Combined Effects of Environmental Factors

Combined Effects of Environmental Factors

BOOK OF ABSTRACTS

Edited by

Olavi Manninen

The Academy of Finland, The Research Council for

Medicine, c/o Department of Public Health,

Medical Faculty, University of Tampere,

PO Box 607, 33101 Tampere, Finland

Third International ICCEF Conference on The Combined Effects of Environmental

Factors is held in Tampere, Finland, at the Hotel Ilves on 15-18 August 1988, under

the auspices of The International Society for Complex Environmental Studies (ISCES)

in cooperation with many internationally honored experts, companies and

organizations representing versatile competences and scholarships.

The Local Organizing Committee contains representatives of different fields; its

members are Minister Mr. Jarmo Rantanen, Member of Parliament Mr. Matti

Hokkanen, Mayor of City Heinola Mr. Jarkko Paronen, Vice Director Mr. Pekka Kari,

Managing Director Mr. Rafik Neuman, General Director Mr. Mauno Ahonen,

Marketing Director Mrs. Pirjo Hallama, Chairman Mr. Olavi Manninen, and Secretary

General Mrs. Ritva Manninen. The Conference Secretariat is comprised of Mr. Olavi

Manninen, Mrs. Ritva Manninen, Mrs. Merja-Riitta Ryynänen, Mr. Antti Perttula, Mr.

Harri Airaksinen, Mr. Glen Orlando, Miss Tuula Keinänen, Mr. Kari Peltola, Miss

Saila Pitkänen, and Mr. Seppo Siuro.

This Book of Abstracts consists of 55 reviewed, accepted, and edited abstracts

involving presentations at the conference.

RESEARCH PROGRAM ON THE COMBINED EFFECTS OF ENVIRONMENTAL FACTORS

Tampere, Finland

Publishing Office S. Siuro, Tampere, Finland

Printed in Finland by Pk-Paino Oy, Tampere, Finland 1988

Combined Effects of Environmental Factors: Book of Abstracts ICCEF 1988

Welcome Address

The complex environmental conditions and their interactions are among the

most central and problematic questions in the field of traditional medicine,

public health, environmental health, occupational health, toxicology, labor

protection, ergonomics, environmental technology and environmental

planning. The study of such combined effects is thus of current interest not only

in scientific terms, but also as far as everyday life is concerned.

The two previous conferences have unambiguously proved that plausible

progress and concrete results can be achieved in this topical area. To ensure the

continuation and nourishment of the international process The Third

International Conference on The Combined Effects of Environmental Factors is

held on 15 - 18 August 1988 in Tampere, Finland, at the Hotel Ilves.

We are very delighted to note that once again our international conference is

attended by a great number of distinguished researchers and experts, whose

research reports cover the latest top achievements in the study of

environmental factors.

We wish that your stay and work here in our hospitable city of Tampere will

prove both productive and pleasurable, and will encourage us to persistently

continue our efforts to gain ever better understanding of the complex

phenomena involved in this field of research.

Olavi Manninen

Chairman

Editor-in-chief


[1] COMBINED WORKLOAD, METHODOLOGICAL CONSIDERATIONS ON THE PRESENT RESEARCH

Van Dormolen M, Hertog CAWM

Dutch Institute for the Working Environment (NIA), Amsterdam, Netherlands

In an extensive literature review, the available studies on combined workload were

collected. The literature search resulted in approximately 300 studies of which the

majority was published within the last 10 years. In this review all factors concerning

the structure of work are defined as stressors. This definition includes factors

stemming from the structure of the task itself, from environmental factors, from the

formal conditions of employment and from the working relations. This paper deals

with a number of methodological considerations concerning the analysis of

combined workload and holds critical comments on premises and methods scientists

are dealing with this subject. Among the subjects that will be discussed are: 1The

necessity of a broader concept of combined workload than one restricted to

environmental factors. This is illustrated with examples of interaction between

environmental factors and the task structure, 2The (lack of) validity of performance

measures as indices of workload, 3The structure of post-work tests as a confounder in

the assessment of workload, 4The influence of the choice of subjects from homogenous

populations as male students or military personnel on the external validity of the

results; the need to focus more on high risk groups, 5The definition of the concepts of

interaction, synergism and antagonism and their usefulness in the application of the

results of experimental research in existing work situations, and 6Laboratory versus

field studies, and their complementary function.

[2] SOME METHODOLOGICAL AND PRACTICAL ASPECTS OF COMBINED

EFFECTS OF ENVIRONMENTAL FACTORS

Izmerov NF

Institute of Industrial Hygiene and Occupational Diseases, USSR Academy of Medical Sciences,

Moscow, USSR

Studies on combined effects of chemical, physical and biological environment

have become important nowadays. Many researches study dose-effect

relationship to determine the isolated effect of a factor. However, in real

conditions we have to deal with multifactorial effect. It is a combination of work

and non-work exposures, physical and mental load, negative social

consequences, bad habits and style of life, personal perceptibility. The mixture

of these exposure elements may cause quite a number of systemic diseases. We

suggest different indices to value effects of factor complex, for instance, total

population morbidity.


Epidemiologic researches have shown that changes in health in 38.0 %

depended on work conditions, in 20.0 % - due to environmental

contamination (i.e. air and water pollution), and in 27.0 % - due to social factors

and stresses. The problem can be settled only by a multiple study using

experimental, clinical and epidemiological investigations.

[3] THE EFFECTS OF NOISE, HEAT AND VIBRATION ON A COMPLEX TASK

Sandover J

Department of Human Sciences, University of Technology,

Loughborough, Leicestershire, England

One might expect a mix of environmental stressors to interact with

each other as regards their effect on task performance. However, it

is not easy to carry out applied investigations on this as one has to

take into account the problems of "direct" versus "indirect"

influences, differences in stressor intensity and characteristic,

exposure duration, task complexity and operator strategy and tactics,

and task realism. We have attempted to ameliorate these problems by

using a functional approach to the design of our computer -based,

complex, information processing tasks by using large clear displays

and large keys for simple responses, by using heat, noise and vibration

stressors of similar characteristic and level to normal transport

situations, and by using long exposures in a workaday situation for

the subjects. Our results show that complex, information processing

tasks are affected by environmental stressors but that the interactions

are still difficult to explain.

[4] WORKLOAD, PERFORMANCES AND PHYSIOLOGICAL RESPONSE UNDER ENVIRONMENTAL AND TASK LOADING STRESS

Von Gierke HE, Albery WB

Biodynamics and Bioengineering Division, Armstrong Aerospace Medical

Research Laboratory, Wright-Patterson AFB, Dayton, Ohio, USA

The effects of biodynamic stressors (two levels of noise, two levels of

sustained acceleration) and dual psychomotor task difficulty (8 degrees of

difficulty) on performance, physiological response and subjective workload

assessment were studied on 9 subjects during 60 seconds exposures. The

results indicate that biodynamic stressors, as well as task difficulty,

adversely affect subjective operator workload without necessarily affecting

objective task performance. Most physiological workload measures do not

correlate well with the subjective workload assessment.


[5] COMBINED EFFECTS OF NOISE AND VIBRATIONS ON PERFORMANCE AND PHYSIOLOGICAL ACTIVATION

Cnockaert JC, Damongeot A, Floru R

Department of Environmental Physiology, Institut National de Recherche et de

Sécurité (INRS), Vandouevre, France

The purpose of this study was to investigate the combined effects of noise and vibrations

on performance and physiological activation in a vigilance task during simulated

driving. The driving scene and symbolized vehicle were generated by a computer.

Interrupted vertical lines of equal lengths were sweeping along the central axis of the road

from top to bottom of the screen. They constituted the irrelevant signals in the vigilance task.

The relevant signals were slightly longer lines occurring randomly among the others. The

subjects were required to maintain the vehicle in the middle of the right lane and to

respond as far as possible to relevant signals by depressing the brake pedal. The

experiment had four conditions: control (C), noise (N), vibrations (V) and noise plus

vibrations (N+V), similar to those in a real truck cabin, i.e. noise with dominating

low frequencies and a A weighted level of 80 dB and vertical broadband vibrations

with a 2.5 Hz peak and a Z (axis) weighted acceleration of 0.9 m/s2. The task lasted two

hours. Response time to relevant signals (RT), omission rate (0), steering control

of vehicle position, heart rate (HR), alpha Index (AI) and beta Index (BI) determined

from EEG were continuously recorded. The average RT and 0 do not show significant

changes across the conditions but the variability of RT increases under isolated or

combined effects of noise and vibrations. Mean HR and BI increased and AI decreased in

stress conditions. These changes were more pronounced under combined stressors

(N+V). The RT and the steering control tended to decrease in the second half of the task.

The progressive decline of HR and BI and progressive increase of AI over time in (C),

(N) and (V) conditions became much more marked in (N+V) condition. Thus, cerebral

and autonomic arousal increase under stress conditions without significant

performance changes. The cerebral and autonomic arousal decline over time and this is

not related to their average level. Both noise and vibrations act in the same direction but

the final effect of their combination seems to be controlled by cortical reticular

homeostasis mechanisms.

[6] COMPARATIVE MAGNITUDES OF PERFORMANCE CHANGES RESULTING

FROM ENVIRONMENTAL STRESSOR AND MOTIVATIONAL VARIABLES

Strong RJ

Institute of Naval Medicine, Alverstoke, Gosport, Hants, United Kingdom

The Institute of Naval Medicine at Alverstoke has conducted a series of trials

investigating the effects of the gas HALON 1301 on task performance. HALON

1301 had been proposed for use in a total flooding firefighting system at sea, and the

primary objective of the studies was to identify possible health and performance


hazards of the gas, which is a narcotic in low concentrations. The trials design used a

series of repeated-measures experimental studies, small groups of subjects being

confined within a special research chamber with associated living accommodation,

each group for up to three weeks. While not the major purpose of the trial, we

were able to observe effects of variations in leadership competence, group

cohesiveness, and the occurrence of unexpected events. These findings will be of

interest to those concerned with the performance of small groups, and in particular

provide quantitative evidence of the comparative magnitude of performance changes

due to group characteristics and processes and to more conventional external

stressors. Our observations show the following: 1The performance of one group

(known to one another and with a clear leader) remained consistently stable

throughout a three week period, while another group's (of mixed background, not

known to one another, and with no clear leader) did not, despite initial training

performance of the two groups being comparable. 2The occurrence of a significant

event (denial of a request for an expected social activity) was sufficient to cause a huge

change in group performance. This change was of considerably greater magnitude

than that due to the experimental stressor variable (the firefighting gas). 3The

magnitude of this effect was independent of the degree of task practice and suggests

that motivational changes may be of equal significance for all tasks, although

changes due to external physical stressors may be greater for less well practiced

tasks. It may be concluded that: 1Good leadership and high group cohesion can lead to

greater consistency and predictability of small group performance, 2Performance

changes due to motivational factors can be considerably greater than those due to

environmental stressors, and 3Overlearning of tasks may provide resistance to increased

environmental stresses, but not against motivational variations.

[7] COMBINED EFFECT OF WHOLE-BODY VIBRATION AND LOW-

FREQUENCY NOISE ON THE HUMAN ORGANISM

Suvorov GA

Department of Physical Factors, Institute of Industrial Hygiene and Occupational Diseases

of USSR Academy of Medical Sciences, Moscow, USSR

The mass investigations of operators exposed to noise and vibration of low

frequency range (lorry and car drivers, operators of concentrators and agricultural

tractors, weavers) showed that combined effect of those factors manifested in signi-

ficant changes of functional state of vestibular analyzer, hearing loss mainly on low

audiometric frequencies and early development of vegetative vascular dysfunction that

revealed the synergic character of interaction and mutual deteriorative effect of noise and


vibration. Combined exposure to noise and vibration resulted in their sub additive effect on

functional state of main physiological systems. The results of field investigations and conducted

experiments underlines the necessity of differentiated approach to hygienic rating of noise and

vibration as the most wide-spread factors of working environment taking into account the

peculiarities of their combined effect to estimate real load on operator and to maintain good

health and optimal conditions of work.

[8] A CONTRIBUTION TO IDENTIFICATION OF NONLINEAR BIODYNAMIC OSCILLATORY MODEL OF MAN

Demic M

Faculty of Mechanical Engineering, Kragujevac, Yugoslavia

In optimizing oscillatory parameters of motor vehicles, there is a need to use

biodynamic oscillatory models of human body. Since all the oscillatory excitations that a

man is exposed to in vehicle, are most often random, and sometimes shock or

harmonic, use of many well-known models (described in literature) would not give

acceptable results in all characteristic cases. Therefore, based on the test obtained data on

input mechanical impedance of a man in passive sitting position, this paper has made

an attempt to identify non-linear biodynamic oscillatory model of a man namely, a

man is approximated by three concentric masses, mutually connected by non-linear

and linear damping elements. Using electronic computer various parameters were

identified. These parameters enable very good simulation of human body behavior

under influence of random, shock and harmonic excitation. The paper also indicates

that it is better to use simple non-linear than complex linear biodynamic oscillatory

models in optimizing characteristics of motor vehicles.

[9] THE INFLUENCE OF NOISE, INFRASOUND AND TEMPERATURE ON DRIVER PERFORMANCE AND WAKEFULNESS DURING STANDARDIZED CONDITIONS

Nilsson L, Morén B, Törnros J

Swedish Road and Traffic Research Institute, Road User and Vehicle Division,

Linköping, Sweden

The environment within a motor vehicle is believed to affect the

driving performance and wakefulness of the driver. Knowledge, about

how and to what extent the driver is affected, is however lacking due to

the fact that very few realistic studies have been carried out. The effects on

traffic safety, if any, are therefore also unknown. The objective of the

present study was to assess the influence of noise, infrasound and

temperature on performance and wakefulness of drivers driving a simulator,

where they can be exposed to realistic and controlled environmental as well as

driving conditions. 48 young, healthy individuals drove the VTI driving

simulator for about 4 hours.


They were exposed to different combinations of noise, infrasound and

temperature. Two values of each of these variables, representing low and high

levels measured in real traffic, were used. The experimental design thus

included 8 different experimental conditions (combinations) with 6 drivers

exposed to each condition. As dependent measures of driving performance we

used steering precision, speed keeping and stimuli-induced reaction time,

while EEG, ECG and EOG were recorded for the assessment of wakefulness.

Audiometry was carried out, before and after exposure, to observe possible

temporary hearing losses. The answers from questionnaires given to the

subjects indicate their subjective evaluations of sleepiness and impaired

performance. The experimental part of the study was finished only this March

and interpretation and assessment of obtained data are still going on. The

results will be available and discussed at the conference.

[10] METHODICAL STATEMENT FOR COMPUTER-AIDED INVESTIGATION OF THE COMBINED EFFECT OF NOISE, CLIMATE AND ILLUMINATION

Rentzsch M, Joiko K, Prescher W

Dresden University of Technology, Department of Work Sciences, Dresden,

German Democratic Republic

Working environmental factors can impair both fitness and wellbeing of

man, particularly with their combined effect. Especially in case of mental

performances, results will be modified by the level of cognitive activity

requirements. At the example of activities modelled for automated flexible

manufacturing systems impacts of load onto man caused by the working

environment such as combinations and variations of noise, climate and

illumination will be investigated. By means of a three-dimensional

experimental design performance parameters (number of errors, reaction time),

physiological indicators (heart rate) and psychic indicators (ratings) are in-

volved into experimental methods. In addition to data detected objectively,

sensation of combined load at simultaneous and immediately successive

presentation of two conditions was investigated using the method of pair

comparison as a subjective procedure. For instance, noise and illumination

levels were presented in a contrary mode in order to reduce the high

number of pairs to be evaluated, decisively. The results of the objective

investigations tend to indicate an increasing load of test persons during the

course of test, which is enhanced at rising load due to environment as well

as at growing activity requirements. Test series using the method of pair

comparison in terms of illumination and noise intensity suggest that the

effect of noise dominates concerning the feeling of comfort. Finally,

equivalence considerations of objective and subjective methods in terms of

experienced impairment due to environmental conditions and their impact to

strain and performance will be presented in order to draw conclusions for

measures of a complex design of working environment.


[11] AGED AND YOUNG MEN UNDER COMPLEX ENVIRONMENTAL

EXPOSURES INCLUDING MENTALLY AND PHYSICALLY LOADING TASKS

Manninen O

The Academy of Finland, c/o Department of Public Health, Medical Faculty,

University of Tampere, Tampere, Finland

This study is part of a multi-stage research project into the combined

effects of different environmental factors on the functions of the human

body. This study in particular was set out to explain the significance of

age (and working hours) in changes in the body functions observed when

the subjects were exposed separately or simultaneously to noise and

vibration while performing physically and mentally loading work at an

elevated temperature. The study was realized as a type 2-2-2-2-3 factorial

experiment yielding a total of 48 exposure combinations. The experiment

were participated by 192 healthy, non-smoking male subjects, 64 of whom

were students and 128 Tampere City Transport bus drivers. Half of the

drivers (64) were under 39 and half were over 40 years of age. Before

the exposure tests all subjects were subjected to a thorough medical

examination and physical fitness tests, an enquiry and an interview in

order to chart, among others, such things as their exposure and working

history. To determine the daily exposure doses various measurements were

made with equipment in bus cabins during driving both in winter and in

summer. One personal test took 5½ hours and it was composed of several

consecutive exposure periods of 16 minutes with a break of 4 minutes

between. During the breaks the subjects were either resting in sitting

position in the vibration chair or were subjected to various measurements

to trace changes in their body functions. During the all tests the subjects

were working on a choice reaction apparatus. The classes of mental work

were 1) no competition and 2) competition on least errors in mental arith-

metic motivated by interim information and monetary rewards. The

classes of physical workloads were 1) work at 2 W and 2) work at 7 W.

The noise classes were 1) no noise and 2) a stable 90 dBA broadband

noise. The vibration classes were 1) no vibration and 2) a stochastic

broadband whole body vibration with a frequency range of 2.8-11.2 Hz

(along Z-axis; acceleration 2.12 m/s2). Changes in body functions were

analyzed on the basis of temporary threshold shifts of hearing, blood

creatine kinase activity levels and urinary catecholamine excretion rates.


The results showed that changes in body functions were largely

dependent on the exposure combinations the subjects were exposed to. The

same exposure combinations would have a slightly different effect on

young subjects than on older subjects.

[12] VESTIBULAR EVOKED POTENTIALS - A NEW METHOD FOR STUDY OF

THE COMBINED EFFECTS OF ENVIRONMENTAL FACTORS

Trinus KF

Research Institute of Labour Hygiene and Occupational Diseases, Kiev, USSR

Progress in the industries and high-speed traffic caused the increase of the number of the

people suffering from the vestibular disorders. That is why the search for new diagnostic

methods is very important. In this context the special place is reserved for vestibular

evoked potentials, the method which will show the particular features of information pro-

pagation in the special areas of the brain. The subject of this study is the analysis of

the parameters of the longue-latency vestibular evoked potentials in healthy

persons and the changes of these parameters after the combined effects of

environmental factors. Vestibular sensitivity analysis is used for recordings and data

proceeding. It appears that the threshold of the vestibular evoked potentials lies at the

acceleration range of 5.7±1.8 cm/s2. The potentials consist of the 3 main extremums: P1,

N1, and P2, the latencies of which at the threshold level are: 31.3±7.2 ms, 69.1±9.1 ms, and

157.6±10.5 ms. The increase of the acceleration results in the shortage of the latencies

which may be reflected by the linear regression equations based on the use of the least

squares method: P1 = -0.69x + 33.6, N1 = -0.44x + 64.0, and P2 = -0.13x + 145.1, where x -

acceleration, factor a shows the slope of the regression line, factor b - theoretical

latency of the peak at the threshold level. The data presented shows that the most

acceleration-dependent is P1, and the least P2. The variability analysis shows some

individual and group specifics, for example, for males the least variable is P1 while

for females N1. The preliminary data shows that after the action of vibration, noise

and workload in different combinations as to the intensities the vestibular threshold levels

rise, latencies of the peaks increase especially at the small acceleration, coefficients of

variation and factors a and b in linear regression equations also increase. The most

impressive changes are caused by vibration, the least by noise. We hope that the method of

vestibular evoked potentials will be useful for studies of the combined effects of

environmental factors.


[13] A STUDY OF THE EFFECTS OF LOW-INTENSITY NOISE AND MILD HEAT

ON COGNITIVE PERFORMANCE AND THE FIVE-CHOICE SERIAL REACTION

TASK

Hygge S

Human Criteria Laboratory, National Swedish Institute for Building Research,

Gävle, Sweden

From the arousal theory and from the perspective of an assumed de-arousing

effect of mild heat and an arousing effect of noise, it can be predicted that more

demanding cognitive tasks would show an antagonistic interaction between

noise and heat. Alternative theoretical approaches, such as information

overload theories or shift in cognitive strategy theories have a problem in

explaining how one stressor can cancel the effects of another. Present study was

designed to further explore interactions between mild heat and low intensity

noise on an array of cognitive performance tasks and on the five-choice serial

reaction time task. In a factorial design two levels of ventilation noise (38 dBA

and 53 dBA) were crossed with two temperatures (19⁰C and 27⁰C). A total of

64 subjects (32 males, 32 females) completed the experiment, and the four

experimental groups had similar distributions of sex and age. The sessions

lasted 2 hours 20 minutes while the subjects worked with mental arithmetic,

incidental learning, hidden geometrical figures, proofreading, verbal fluency

and the five-choice serial reaction task. To increase the sensitivity of the tests

employed, all subjects took part in a pre-experimental standard session exactly

24 hours before the experiment proper. In the pre-session subjects worked in 38

dBA and 20⁰C with parallel versions of all the tests given in the experiment

proper. Multivariate analyses of variance were performed on the difference in

performance between the two sessions. Results indicated an antagonistic

interaction between heat and noise on the hidden figures test. For the incidental

learning task, noise biased the response criterion towards being stricter. On the

five-choice task, the higher temperature increased the rate of responding

without increasing errors. The results are discussed in relation to arousal theory

and alternative explanations. Time-of-day effects and sex effects will be briefly

indicated, as well as the results of a factor analysis of the tests in the pro-

experimental session.


[14] PHYSIOLOGICAL BACKGROUND OF CHANGES IN PROSODIC FEATURES OF SPEECH UNDER COMPLEX ENVIRONMENTAL EXPOSURES

Manninen O1, Vilkman E2 1The Academy of Finland, c/o Department of Public Health, Faculty of Medicine, University of

Tampere, Tampere, Finland 2The Department of Phoniatrics, Clinic of Otolaryngology, Tampere University Central Hospital,

Tampere, Finland

In an earlier study we investigated the variation in prosodic features of speech

under exposure to 12 combinations of three environmental factors: dry bulb

temperature (200C, 350C), stable broadband noise (90 dBA), and stochastic broadband (2.8-

11.2 Hz) as well as sinusoidal (5 Hz) whole body vibration along the Z-axis (acceleration 2.12

rn/s2). Sixty healthy, young male subjects read a text which was analyzed. The changes in

prosodic features (i.e. fundamental frequency, intensity, time) were found to depend on

the exposure used and, thus, assumed to reflect changes in the arousal or

psychophysiological state of the reader. The special purpose of the present

study was to investigate the background of these prosodic changes by studying

their relationship to changes in physiological measures, such as heart rate, blood

pressure, urinary catecholamine as well as hearing thresholds. The physiological data has been

published before. In this report results from correlative analyses between the prosodic and

physiological variables will be presented.

[15] SIGNIFICANCE OF THE ADDITIVE MODEL IN THE EVALUATION OF COMBINED ENVIRONMENTS OF TEMPERATURE, NOISE AND ILLUMINANCE IN A ROOM

Sakurai Y2, Matsubara N1, Noguchi T2, Horie G2

1Department of Housing and Design, Faculty of Living Science, Kyoto Prefectural

University, Kyoto, Japan 2Department of Architecture, Faculty of Engineering, Kansai University, Osaka, Japan

The purpose of this study is to find the way for the design of combined environment in a

room as a whole. This paper discusses the concept of the two scales - specific one

to a certain environmental factor and nonspecific one not depending on a kind of

environmental factors, and discusses the significance of our additive model by

reconsidering the results which were obtained in the past study. Most of the studies on

the environmental evaluation are limited to those on a single environmental factor and few

studies treat several factors synthetically, while there are many environmental factors in a

room. Although there are several studies on the evaluation of the combined environmental

factors, their main interest is the evaluation specific to a single environmental factor and

not the synthesized evaluation common to every factor.


However, specific scale on a single factor is not always useful when the

improvement of whole environment is aimed. It is necessary to introduce the concept of

the synthesized evaluation on the nonspecific scale. The numerical contribution called a

weight score of each environmental factor - temperature noise and illumination - to the

synthesized evaluation of "uncomfortableness" is determined by applying the Second

Method of Quantification of Hayashi to the experimental responses on the linear combi-

nation simulation. It is demonstrated that "nonspecific uncomfortableness" is expressed by

the addition of each weight score for a corresponding category in each factor. With this

method, the added score of "uncomfortableness" to the daily combined environmental

factors can be predicted in the moderate range. The comparison of effects of different

kinds of environmental factors is now possible on the common scale. Then the

dividing points between classes of "uncomfortableness" are obtained to predict with the

largest probability at any given condition. The prediction of evaluation, one of the classes,

for a given combined environment is possible with this result. A few examples how

to apply these quantified results to an environmental design are shown. It is discussed

that the synthesized evaluation by utilizing the nonspecific scale is necessary and a specific

scale is not so much useful in the design of combined environment.

[16] THE COMBINED EFFECT OF FORMALDEHYDE AND RADIANT HEAT ON ODOR STRENGTH

Berglund B, Berglund U, Högman L, Olsson MJ

National Institute of Environmental Medicine and Department of Psychology,

University of Stockholm, Stockholm, Sweden

Formaldehyde is an odorous substance that above a certain concentration is assumed

to cause nasal trigeminal stimulation (i.e. perceived irritation). The trigeminus is also

sensitive to heat and people tend to report a tickling feeling in the nasal cavity

when suddenly exposed to sunlight. This may reflect a change in the nasal mucosal

conditions due to radiant heat. An experiment was undertaken in order to study the

possible influence of radiant heat on perceived odor strength and irritation. The

stimuli were eight concentrations of formaldehyde presented alone in a hood or

together with three levels of radiant heat. The whole face was exposed to both the

radiant heat and the formaldehyde. The method of free number magnitude

estimation was used by 20 observers to judge the odor strength of the inhaled stimuli

(warmth was not judged). The eight concentrations of formaldehyde ranged from

50 to 1000 ppb in logarithmic steps. The radiant heat stimuli were: no heat, supra

threshold heat, "weak" heat, and heat. The results show that observers report

higher odor strengths at low concentrations of formaldehyde when radiant heat is

perceived. Out of 20 subjects, 15 found formaldehyde to produce sensory irritation at

some concentration or another.


Most observers reported nasal irritation. Several of them reported throat irritation, and

only a few eye or facial skin irritation. A change in the odor percept due to the presence

of supra threshold radiant heat was reported by 15 subjects out of 20; the odor percept

gets more pungent (as if mediated by the trigeminal system) and there is a tendency of a

qualitative change towards a less "saturated" smell.

[17] PHYSIOLOGICAL REACTIONS OF WOMEN TO COMBINED STRESS OF

WORK AND HEAT

Nag A, Nag PK

National Institute of Occupational Health, Indian Council of Medical Research,

Ahmedabad, India

Physiological responses and work output of six women exposed to

different environmental warms (30, 35 and 40°C dry bulb temperature

with 50, 70 and 90 % RH) were examined. Based on the study a permissible

level of heat exposure for women has been suggested. The O2 demands

due to combined load of work and heat were 30 to 40 % of aerobic work

capacity. The local and mean skin temperatures (Tsk) were significantly

influenced at lower heat loads up to about 4-5 KPa. Both heart rates

(100-110 beats/min) and deep body temperature (Tdb ) (37.0-37.5°C) were

largely independent of vapor pressures up to 4-5 KPa. At higher heat

loads, the heart rates and Tdb raised linearly up to about 140 beats/min

and 38.5°C by 3rd hour at 6 .7 kPa, when the gradient of T s k and Td b

was around 1.0°C. The work output remained constant up to the ambient

load (4-5 kPa) and at higher vapor pressures there were drastic fall in

output with the time of exposure. Also the women reported the thermal

sensations as more or less comfortable up to 4-5 kPa. The conditions

beyond 5 kPa were stressful to women and may not be allowed for conti-

nuous exposure.

[18] PSYCHOLOGICAL AND PSYCHOPHYSICAL SCALINGS OF ANNOYANCE

COMPARED WITH PHYSIOLOGICAL MEASUREMENTS

Spreng M

Department of Physiology and Biocybernetics, University of Erlangen, Erlangen, FRG

With respect to their annoyance environmental impulsive and fluctuating sound

configurations (traffic, pile driving, gun fire, low-level military overflights) were judged

by subjects of different sex and age using psychophysical (quasi-reflective) power/work

handgrip - scaling and psychological category scaling (1 to 10 annoyance scale). In

addition, the change of heart rate has been measured and processed by a specialized

microcomputer-based system. Psychophysical scaling of verbal graduations of annoyance

allowed the combination of the latter with the psychological category scaling results and

revealed a remarkable agreement with direct psychometric graduations, thus validating the


handgrip scaling method. This psychophysical method proofed to be most valuable in

scaling the degree of annoyance during a longer lasting influence of environmental

factors. It could be shown, that most subjects, especially the older ones (mean age 49.1

years) scaled remarkably increasing values of annoyance during the whole duration

(5.5 minutes) of the sounds, the younger subjects (mean age 24.0 years) presented nearly

constant values (only grouping young females resulted in slightly decreasing

psychophysical scaling values over time). It is remarkable that the three different areas of

measurement (both scaling as well as the change of the heart rate) showed the same re-

lationships between typical environmental noises (e.g. significant higher reactions for

traffic if compared to gun-fire). It must be concluded that psychophysical handgrip-

scaling is an appropriate method to scale sequentially the annoyance of longer lasting

environmental effects and in combination with physiological measurements may be

helpful to evaluate the processes of sensibilization and habituation.

[19] COMBINED EFFECT OF NOISE, LOCAL VIBRATION, HEATING

MICROCLIMATE AND RATIONAL WORKING ROUTINE WITH STATIC STRAIN

Menshov AA, Schleifman FM, Gorban VS, Tashker ID

Research Institute for Labour Hygiene and Occupational Diseases, Kiev, USSR

A combined effect of three levels of noise (82, 81 and 92 dBA), local vibration

(corrected levels 108, 114 and 120 dB), air temperature (22, 28 and 34⁰C) and

mobility (0.65, 1.75 and 3.0 mps) upon man was reproduced in a laboratory

experiment. The investigated subjects pressed with a 200 N effort over 60 minutes

summarily a knob of a vibration-testing machine which imitated the process of

work with a hand tool in a deep coal mine. The duration of one pressing made 6

minutes corresponding thus to a single exposure to noise and vibration with 3

minutes lasting pauses. 17 variants of experiments were carried out with different

combinations of the investigated factors in accordance with the requirements of

mathematical experiment planning. We studied changes of specific indices (auditory

and vibrational sensitivity, skin temperature and moisture losses) and non-

specific ones (heart rate, latent period of the reaction to a stimulus etc.). The

solving of multiple regression equations made it possible to determine corrections

for allowable rates of noise and local vibration depending on the investigated range of

air temperatures under combined exposure there to - for noise -1 to -8 dB, for local

vibration -5 to 2 dB. In 9 variants of the experiment we studied human

reactions during work with 170, 200 and 300 N static effort, while the duration

of a single noise and vibration exposure made 2.5, 5.0 and 7.5 minutes (totally 60


minutes), the preceding data were taken into consideration. On the base of multiple

regression equations solution we have determined rest coefficients necessary upon

single exposures, said coefficients amounting to the break duration-towards

noise/vibration exposure length ratio. The duration of work making 2.5, 5.0, 7.5

minutes, they range respectively from 0.5 to 0.2 minutes for 170 N, from 0.5 to 0.4

minutes for 200 N and 0.7 minutes for all the variants for 230 N.

[20] COMBINED EFFECTS OF LOCAL VIBRATION AND COLD ON

PERIPHERAL CIRCULATORY FUNCTION

Nohara S, Nakamura H, Nakamura H, Kimura S, Kubota M, Okada A

Department of Public Health, School of Medicine, Kanazawa University, Kanazawa,

Japan

Local vibration and cold are known respectively as one of the factors, which may

induce vibration hazards. This study was designed to compare the changes of

finger blood flow by exposure to a combination of local vibration and cold with

those by exposure to either stimulus alone. Six healthy subjects were exposed for five

minutes to four different kinds of exposure conditions as follows: 1) Local vibration

(120 Hz, 50 m/sec2) alone at the room temperature, 2) Cold alone (4°C), 3)

Combination of local vibration (120 Hz, 50 m/sec2) and cold (4°C), and 4)

Control i.e. neither local vibration nor cold. The finger blood flow significantly

decreased in comparison with the initial value when the subjects were exposed to

local vibration or cold. In the combination of the local vibration of 120 Hz and cold

(4°C) the finger blood flow remarkably decreased compared with that during the

exposure of vibration of 120 Hz or cold (4°C) and showed significant changes during

exposure of the combination.

[21] WHEN DOES SYNERGISM EXIST? THE ROLE OF THE EXPOSURE-EQUIVALENT PRINCIPLE

Ward WD

Rearing Research laboratory, University of Minnesota, Minneapolis, Minnesota, USA

An exposure A1 to noxious agent A produces effect E(A1) in some characteristic

E. Exposure B1 to agent B produces effect E(B1) in that same characteristic.

Assume E(A1) to be greater than E(B1). Combined exposure A1+B1 leads to effect

E(C). If E(C) is less than E(A1), B can be said to ameliorate the action of A (or

vice versa); if E(C) is greater than E(A1)+E(B1), synergism clearly exists. But

what of the zone in between: E(A1)<E(C)<[E(A1)+E(B1)]?


If the function that relates E to A is already known, then the "exposure-

equivalent" rule can be invoked. One can determine that particular exposure to

A, designated AB, which would have the same effect E(AB) on E that B1, did, i.e.,

E(B1)=E(AB), as well as the expected effect of administering both A1 and AB,

E(A1+AB). If A and B act at the same site, then one would expect E(A1+AB) and

E(C)to be equal, in the absence of any interaction. On the other hand, if A and B

act independently (at completely different sites) then E(C) would be expected to

be [E(A1)+E(AB)], which of course is the same as [E(A1)+E(B1)]. Thus the only

values of E(C) that would remain ambiguous would be those between E(A1+AB)

and [E(A1)+E(B1)]; values below E(A1+AB) would now imply amelioration, and

values above [E(A1)+E(B1)] would indicate synergism. Values in the remaining

zone of uncertainty will represent synergism if the sites of action of agents A

and B are known to be identical, amelioration, if the sites are completely

independent. Indeed, one interpretation that could be made, although,

unfortunately, not the only one, of the actual position of E(C) in this ambiguous

zone is that it reflects the degree of overlap of sites of action of the two agents.

Two specific examples of the usefulness of the exposure-equivalent principle

will be presented, one dealing with the interaction of noise and aspirin, the

other involving steady noise and impulse noise. In the former case, application

of the principle clearly implies synergism (at least when noise exposure follows

aspirin administration), while in the latter, amelioration is found when steady

and impulse noise are presented simultaneously.

[22] COMBINED WORKLOAD, A REVIEW OF PRESENT KNOWLEDGE

Hertog CAWM, Van Dormolen M

Dutch Institute for the Working Environment (NIA), Amsterdam,

Netherlands

The literature on combined workload shows an immense divergence in

research methodology and conceptual framework. Comparison of the

results from the available studies is therefore a difficult task. In

order to provide a basic understanding of the complex problems,

met on the shop floor, the authors made a systematic inventory of

the research literature. Attention was paid to the ways in which

several factors related to organizational structure, work task and

working environment interact and affect health and well -being of

the employed. In an on-line search in several databases the

literature was screened on general terms as "combined workload",

"multiple exposure" or "synergism". The literature was also sifted

by combining existing thesaurus-terms.


This combined approach resulted in about 1300 tit les. After

selection on the basis of the information provided in the abstracts,

a corpus of about 300 studies remained as a fundament for the

literature review. These studies were checked on their relevance for

actual working condit ions or conceptualizat ion of combined

workload. In this paper the results of the invento ry are presented

and comment is given on the current lack of applicable knowledge

on many subjects in the field of combined workload.

[23] HEALTH SURVEILLANCE OF LOW-LEVEL OCCUPATIONAL EXPOSURE TO ORGANIC SOLVENT MIXTURES IN LABORATORY WORKERS

Grafstein O, Lemesch C, Rav-Acha C, Sanchez M, Pines A

Division of Human Environmental Sciences, Hebrew University of Jerusalem and

Occupational Medicine Department of the General Workers Sick Fund, Division

of Human Environmental Sciences, School of Applied Science and Technology,

Hebrew University of Jerusalem, Jerusalem, Israel

Exposure to mixtures of organic solvents that fluctuate widely in qualitative and

quantitative terms is a feature of laboratory work. These fluctuations decrease the value

of environmental monitoring in risk assessment. A health-surveillance screening panel

was piloted as an alternative method of identifying workers at risk in a typical

chemical factory; 63 solvent-exposed employees were compared to a group without

known solvent exposure. Risk indicators included both subjective (self-reported solvent

exposure and self-reported health symptoms) and objective (blood count hematology at

different time points, routine biochemistry and urine delta-aminolevulinic acid, ALA)

variables. The most frequent solvents used were benzene (reported by 36 % of the

exposed group), toluene (45 %), methylene chloride (24 %) and methanol (45 %),as well as

others (chloroform, ethyl acetate, acetone, ethanol, petrol ether, xylene, butanol, pyridine,

acetonitrile, and hydrogen sulfide) - most workers reported daily exposure to at least 5

different solvents and related chemicals. Health complaints (noted at least 3 times per

week when working) in laboratory workers vs. controls included eye irritation (31 %

versus 4 %, p<0.001), skin irritation and rashes (16 % versus 4 %), headache (36 % versus

19 %) and dizziness (22 % versus 12 %). Controlling for potential confounders such as

age, sex and smoking by ANOVA did not eliminate higher reporting by exposed workers,

RBC counts showed a clear shift between exposed and control workers: median

values were lower in solvent-exposed workers, which might be attributed to

frequent use of benzene and/or toluene contaminated with benzene. In several workers, a

longitudinal trend of decreased RBC values was also observed. Biochemical

values (AP, GOT) were not different among the two groups; however, ALA values were

increased for the urines of laboratory workers versus controls. In all, over half of the

workers exhibited at least 2 self-reported health complaints possibly due to mixed

solvent exposure and RBC values below the median for their sex. Selection of an

appropriate indicator battery for individuals with multiple overlapping and

potentially interacting exposures is discussed.


[24] COMBINED EFFECT OF JOB DEMANDS AND JOB DECISION LATITUDE ON LEAD IN BLOOD

Ulenbelt P, Lumens M, Cron H, Herber R, Meijman T

Work and Health, Coronal Laboratory, Amsterdam, Netherlands

The effects of interaction of formal job characteristics (job demands and job

decision latitude) and hygienic behavior at the workplace on uptake of

airborne lead and on lead in blood are studied. Workers in an

electric accumulator factory (n=30) responded to a questionnaire.

Moreover their hygienic behavior was observed during five working

days. Lead in air (PbA) and lead in blood (PbB) was measured. The

correlation between PbA and PbB is R (PM)=0.42. The correlation

between job decision latitude and PbB is R ( P M ) =0.55 and between the

use of personal protection devices and PbB is R(PM)=0.46. Job demands and

personal hygienic habits are not correlating with PbB levels. Job

demands and job decision latitude are both negatively related to

the use of personal protect ion devices (respectively R ( P M )=-0.59).

Moreover, a combined effect of job demands and job decision

latitude on PbB is demonstrated. Both job decision latitude and the

use of personal protection devices explain more variation in PbB

levels than the exposure to PbA does.

[25] THE RELATIVE IMPORTANCE OF NOISE WITHIN THE SCOPE OF COMBINED STRESS FACTORS AT WORKPLACES

Schwarze S, Jansen G

Institute of Occupational Medicine, University of Düsseldorf, Düsseldorf, Federal

Republic of Germany

A longitudinal study into the effects of noise on health in comparison to other

stress factors of the workplaces was carried out with a sample of 29 employees

of a military service unit. Out of 31 stress factors 6 variables relating to the

working conditions proved to be relevant for health state. Analyzing the

predictors for general health by calculating multiple regression, time stress

was the most important variable, followed next by noise annoyance. Subdividing

the general health score into 11 different groups of diagnoses, still two third of the

criteria showed significant explanations of variance. The relative importance of

the predictors varied between the groups of diagnoses. Time stress was the

dominating variable for the group of gastrointestinal diseases and for the group

of urogenital diseases.


For neuro-vegetative disorders and diseases of ear, nose and throat, time stress as

well as noise annoyance and duration of noise exposure were relevant predictors.

Cardiovascular disorders were mostly related to the noise variables. Evaluation

models are presented how to assess noise effects.

[26] INVESTIGATIONS OF THE RISK OF HEARING DEFECTS FOR THE

OCCUPATIONAL GROUPS OF WELDERS AND PLANT ASSEMBLY

WORKERS

Rentzsch M, Minks B

Department of Work Sciences, Dresden University of Technology, Dresden,

German Democratic Republic

Welders and plant assembly workers represent a high proportion of

occupational diseases caused by noise. This suggests primarily a considerable

risk of hearing defects. By field studies and findings of occupational

medicine of work the situation in terms of occupational hygiene was

analyzed and characterized. The detected hearing losses of probationer

groups cannot be described by the Dresden noise dose model and, thus,

they can't be understood merely as a consequence of noise load. The highly

increased risk of hearing defects in comparison to the dose model is

intensified by the combined effect of noise and chemical pollutants (CO). For a

description of the combined effect and extension of the noise dose model is

proposed describing an additional risk of hearing defects as a function of

exposition time and intensity. The ototoxic effect of carbon monoxide is well-

known. The results represent a valuable basis for a more precise specification of

noise limiting values from the aspect of a combined effect including carbon

monoxide

[27] ADDITIONAL EFFECT OF HIGH LEVEL SHOOTING IMPULSES TO THE GENESIS OF SENSORY NEURAL HEARING LOSS

Pekkarinen J1,Starck J1,Pyykkö I2 1Institute of Occupational Health, Vantaa, Finland 2University Hospital of Helsinki, Helsinki, Finland

Sensory neural hearing loss (SNHL) may be caused either by a long term

exposure to noise leading to the metabolic changes in the inner ear or by high

level impulses which produce immediate damage in the cochlea. The criteria

level for immediate damage is still a matter of controversy but according to

several recommendations peak levels above 140 dB should be avoided.

Shooting is known to produce peak levels up to 185 dB. We analyzed the effect of

non-occupational and military shooting impulses on the hearing loss in a group

of 199 forest workers exposed to noise from chain saws.


Our goal was to clarify the relative role of different factors for the incidence of

SNHL which has not diminished in Finland during last ten years in spite of the

wide use of hearing protectors and noise control measures. The total amount of

shooting impulses, weapons and hearing protectors used were inquired in

addition to the occupational history. The attenuation of impulse peak levels by

hearing protectors was measured for the most common weapons. Subgroups

were contrasted by the lowest and highest quartiles of the total exposure to

shooting which was summed for each individual using logarithmic conversion.

Exposure to chain saw noise was calculated as a noise immission level by

Robinson's model including age, noise exposure time and level. The matching

criteria for the contrasted 12 pairs of workers were: no ear diseases, age within

10 years, noise immission level within 5 dB, use of salicylates within 30

tables/month, diastolic blood pressure within 10 mm/Hg, LDL-cholesterol

concentration within 2 mmol/l, same status for smoking and vibration-induced

white fingers. The bilateral hearing level (mean±sem) for the low impulse

exposure group was 21.7±4.6 dB at 4 kHz and 24.4±5.0 dB at 8 kHz, and for

high impulse exposure group 30.8±6.2 dB at 4 kHz and 34.6±6.6 dB at 8 kHz. The

forest workers with higher exposure to shooting impulses had significantly

higher hearing loss at 4 kHz (p<0.l) and at 8 kHz (p<0.05) according to a one-

tailed paired t-test. The peak levels of large caliber weapons exceeded 140 dB

inside the hearing protectors which together with the analysis by matched pairs

revealed that shooting impulses were contributing to the hearing deterioration

in persons exposed to occupational noise.

[28] SMOKING AS A RISK FACTOR IN SENSORY NEURAL HEARING LOSS

Starck J1, Pekkarinen J1, Pyykkö I2 1Institute of Occupational Health, Vantaa, Finland 2University Hospital of Helsinki, Helsinki, Finland

Smoking is generally considered to contribute to the vascular diseases.

However, its role in the development on sensory neural hearing loss (SNHL)

has been controversial. Smoking has been proposed to influence inner ear

directly by the chemical agents in smoke or by circulatory changes in the inner

ear capillaries. While some researchers have shown correlation between

smoking and SNHL some others have not been able to confirm such a finding.

This may be due to the minor effect of smoking on SNHL compared to other

more profound risk factors. The present study was aimed to evaluate the effect

of smoking alone and together with other risk factors on the SNHL among

workers exposed to occupational noise and vibration. The study comprised 199

professional forest workers and 171 shipyard workers.


Their exposure to noise and vibration and health status were examined. The

smoking habits were queried and if more than ten years had passed since

quitting smoking, the subject was classified as a nonsmoker. The permanent

hearing level was measured with audiometry in an acoustically treated room.

Effect of age to hearing was corrected by using Robinson's model. The other

risk factors were blood pressure, low density lipid cholesterol concentration,

and presence of vibration induced white finger. The result showed that

smoking without the presence of any other risk factors does not increase the

risk for SNHL, but that smoking in combination with other risk factors

promotes a higher risk than any of the risk factors alone.

[29] EFFECTS OF MULTIEXPOSURES FOR HANDS IN SNOWMOBILE DRIVING

Virokannas H, Hannu Anttonen H, Niskanen J

Oulu Regional Institute of Occupational Health, Oulu, Finland

The aim of the study was to find out the effects of multiple exposures in

snowmobiling and correlated complaints in hands. Vibration syndrome in

hands is caused more in cold than in warm conditions. Hand vibration and cold

have combined effects for circulation in fingers and noise may also have effects

upon circulation. According to the results of the inquiry for reindeer herdsmen

white finger symptom and numbness of hands increased significantly when

snowmobiling exceeded 6000 h (Group III; Table 1). Persons in every exposure

group had used chain saw equally (Mean±SD 1200±1100 h).

Table 1. The use of snowmobiles and prevalence of white finger symptom and numbness of hands ___________________________________________________________________________ Exposuregroup n Age(y) Snowmobile (h) White finger Numbness

Mean±SD Mean±SD % %

__________________________________________________________________________________

Group I 404 41±16 500±600 11 37 Group II 108 38±13 3700±1100 12 47 Group III 77 42±12 12800±5900 20 61

__________________________________________________________________________________

Vibration was measured in the field according to the standard ISO 5349. The

study included the most popular snowmobiles of reindeer herders (n=24). The

values for weighted acceleration were in hand bar 1.5-6.7 m/s2, mean was 3.3

m/s2 (SD±1.2). The noise levels of snowmobiles were 88-106 dBA, mean was 97

dBA (SD±5). In snowmobile driving Windchill-indexes were 1000-1550 kcal/m2

x min (Ta>-13) and temperatures on fingers decreased considerably. In the

earlier questionnaire 20 % of reindeer herders had occurred frostbite of fingers.


In snowmobile driving the exposures of hand to vibration, noise and cold may

make functions of hands worse. Reindeer herders had had plenty of symptoms

in circulation and in nerves fitted to vibration syndrome in hands.

[30] EFFECTS OF AMBIENT TEMPERATURE AND CLOTHING UPON SKIN TEMPERATURE IN WORK IN COLD CONDITIONS

Virokannas H, Anttonen H Oulu Regional Institute of Occupational Health, Oulu, Finland

The purpose of this study was to estimate the combined effects of cold

environment and clothing in light and moderate work with measurements of skin

temperatures. The results included ergometer tests (n=45) for 60 minutes in a

climatic chamber in combination with workloads (55 and 110 N), ambient

temperatures (-5°C and -150C) and clothing (1.3, 1.5, 2.2 and 2.4 clo). Skin

temperatures were measured by YSI 400 probes at ten sites on the skin. The

relations between mean skin temperature (Tsk), insulation value of clothing (clo)

and ambient air temperature (Ta) were: in light work: Tsk = 20.5 + 5.5 x clo +

0.16 x Ta, and in moderate work: Tsk = 22.5 + 4.8 x clo + 0.11 x Ta. The models

were statistically highly significant (analysis of variance for the full regressions; p

< 0.001). The equations showed that in light work both clothing and ambient air

temperature have greater effect upon the skin temperature than in moderate work.

The change of one centigrade in mean skin temperature was caused by 0.18 clo or

6.30C in light work and by 0.21 clo or 9.10C in moderate work. According to the

results in moderate work it is possible to work with the same clothing on wider

range of ambient temperature than in light work. The results could be useful in

planning of work and clothes in cold conditions.

[31] HORMONAL REGULATION OF ADAPTATION OF MAN TO COMBINED

EFFECT OF ARCTIC CONDITIONS

Tigranian R, Krylov Vu, Kalita N

Institute for Standardization and Control of Drugs, Ministry of Health,

Moscow, USSR

In 10 healthy men, participants in a 380 km skiing march during 17 days,

performed under arctic conditions of the Far North at temperatures -320C

to -340C, the blood content of E, NE, serotonin (S), histamine (H), ACTH,

TSH, GH, PRL, F, T4, T3, insulin, aldosterone, testosterone, glucose,

triglycerides, Na and K, as well as the urinary content of E, NE,

conjugates, metabolites and precursors of catecholamine, F, aldosterone,

Na and K were measured.


Blood samples were taken three times: 5 days before the start of the

march, on the eleventh day of the march, and on the second day after its

completion; collection of the diurnal urine was made in the same

intervals. During the skiing march the blood and urine content of E and

NE increased significantly, as well as the blood S and H levels. After the

completion of the expedition, the level of indices catecholamine

metabolism somewhat decreased, albeit exceeding the pre-expedition

values. During the expedition the blood content of GH, ACTH, aldosterone, T3

and K increased considerably, while that of T4, testosterone and PRL in blood

and excretion of Na and K decreased. In the post-expedition period the

levels of the compounds under study tended to return to the initial

values, except the still elevated blood levels of F, aldosterone, decreased

blood content of T3 and reduced excretion of Na and K. The data

obtained showed that the combined effect of arctic conditions in conjunc-

tion with greater exercise lead to marked changes in adenohypophysis

incretory activity, thyroid gland, adrenals, and gonads, and at the same

time contributed to changes in the fluid-electrolyte homeostasis. The

endocrine system takes the most active part in the adaptation reactions

of the human organism to the climate geographic conditions of high

latitudes; at the same time, in the course of adaptation of man to

strenuous physical loading in the Far North, optimal variants of

functional bonds and levels of activity are developed, ensuring the

normal vital activity of the body.

[32] INDIVIDUAL DIFFERENCES ON THE COMBINED EFFECTS OF NOISE AND NIGHTWORK ON HUMAN PERFORMANCE

Smith A

NRC Perceptual and Cognitive Performance Unit, Laboratory of Experimental

Psychology, University of Sussex, Brighton, United Kingdom

The effects of occupational stressors are usually examined in isolation, which is not

representative of the real-life situation where the individual is often exposed to a

combination of such factors. Noise and night work are two occupational hazards

of health and the present experiment was carried out with the aim of providing

preliminary data on their combined effects. Studies of environmental stressors can

also be criticized because they rarely examine individual differences. Yet it is clearly

important to determine whether any sub-groups are particularly sensitive and the

present paper reports data relevant to this point. Before the start of the experiment 24

subjects filled in standard personality questionnaires measuring introversion-

extraversion, neuroticism, anxiety and morningness.


Each subject was tested from 09.00 to 17.00 and 22.00 to 06.00 (the two sessions

being a week apart and half the subjects being tested in the order day/night and the

others in the reverse order). During each shift the subjects carried out tests

designed to assess perceptual-motor functions, selective and sustained attention and

various aspects of memory. The results for the group as a whole showed that the

effects of noise and night work were independent. This view was confirmed in the

analysis of individual differences, and the only measure found to interact with

noise and night work was introversion, and this effect was only observed for a few

aspects of performance. Overall, these results show that noise and night work have

independent effects on performance, and none of the personality measures

examined here revealed a sub-group who were consistently most sensitive to the

combination of these factors.

[33] THE COMBINED EFFECTS OF NOISE AND NIGHTWORK: NOISE

SENSITIVE VERSUS NOISE INSENSITIVE WORKERS

Koller M, Kundi M, Haider M, Cervinka R

Institute of Environmental Hygiene, University of Vienna, Vienna, Austria

In one of our early studies about health and psychosocial aspects of shiftwork an

interesting finding focused on the perception of noise. Shift workers and the

group of drop-outs (i.e. people who had been transferred from shift- to day

work) showed - whenever the problem "noise" was referred to, a sort of

special "sensitivity". To follow the hypothesis of a "learned" noise

sensitization we initiated another field study on 210 shift workers, 67 day

workers comparable in age, social status and working conditions and 34

drop-outs of an Austrian Oil Refinery. Questionnaires concerning personal

and family data, vocational history, attitudes towards various elements of

shift systems, opinions to different working conditions, an interview referring

to morning/evening type, sleep quality, eating habits, health state,

psychosomatic disorders, special noise sensitization questionnaires were

administered. Comparing shift workers, day workers and drop-outs as to

noise statements, shift workers perceive their noise exposition at work most

and scale the noise most unbearable (significant difference to day workers).

The analysis of items of the sensitization questionnaire shows shift workers to

be significantly more sensitive to noise than day workers. Drop-outs tend

towards shift workers' values.


To examine special traits of the noise sensitive subjects, (the population of shift

workers was divided according to the noise sensitization questionnaire at the

median of the total sample) we found 64 noise "insensitive" shift workers and

146 noise "sensitive" ones and formed two contrast groups. Although they did

not differ in age, the mean duration of night- and shiftwork exposure is

significantly higher in the noise sensitive group. Noise sensitization coincides

further with a number of work and health related conditions in a significant

way: negative attitude towards shiftwork, adverse perception of work strain,

sleep disturbances, lack of coping with shifted meal-times, health and fatigue

problems, depression, various unspecific symptoms, and cardiovascular

disorders. The results might be interpreted in terms of two different theories:

One source of sleeping problems in shift workers' day sleep is the higher

environmental noise levels during day. Noise sensitivity might be a trait

variable which discriminates between shift workers who are more or less prone to

sleeping problems in rather noisy environmental conditions. Since sleep

disturbances might have consequences on family situation and attitudes

towards work) as predicted from our destabilization theory) they might

indirectly be responsible for adverse health effects. On the other hand there

might be a synergism between the load imposed by night work and

occupational noise exposure which is moderated by noise sensitivity.

[34] ENVIRONMENTAL PERCEPTION IN RELATION TO EXPERIENCED ILLNESS BY PATIENTS IN A WAITING-ROOM

Van den Hazel PJ

CG&GD Arnhem/Chemiewinkel, University of Amsterdam, Arnhem,

Netherlands

A structured interview was used on a selective sample of patients in

three different waiting-rooms of General Practitioners (G.P.). The aim

of this pilot study was to do a preliminary exploration of the possibility

to examine the perceived relation between illness and environmental

problems by patients. Data were collected regarding the individual

perception of the environment and the perceived causal relations

between patient's illness and the environment. It was observed that 31 %

of the patients mentioned complaints that in their opinion were related to

environmental problems (n=62). When certain environmental problems

were mentioned in the interview the percentage of patients that men-

tioned complaints in relation to their environment raised to 53 %.


As two practices were near a paper-plant and a sewage-plant the

percentages of hindrance by stench were so high as 91 % and 78 %. Air-

pollution (indoor and outdoor) and noise were the most often mentioned

environmental problems. The results of this pilot study resulted in a second

phase. A self-administered questionnaire among patients in a waiting-

room of G.P.'s dealt with the perceived environmental problems and the

possible health outcome by these problems. Different areas were

compared. The results are still being computed and will be presented at

the conference.

[35] COMBINED EFFECT OF ELECTROMAGNETIC FIELD AND NOISE ON

HEALTH OF WORKERS

Bielski J, Bielska StK

Department of Hygiene and Labour Protection, Agricultural University, Poznan, Poland

Although the effect of electromagnetic fields on the human organism has been in the center

of interest of specialists in various branches of science, still the problems involved have

not been definitely explained. That is why we have undertaken observations of the

combined effect of high frequency electromagnetic fields and noise on the health of

workers, especially on the central nervous system. The results obtained showed, that

most of the employees, operating radio and television installations, exposed to microwaves

of 3000-7000 MHz frequency, in exposition ranged from 0.1 W/m2, periodically to 2.0

W/m2, not exposed to noise, complained different nonspecific symptoms, as excessive

irritability, increased perspiration, headaches and dizziness, heartaches, etc., the symptoms

of vegetative neurosis. No focal changes in the central nervous system were found, but in

the employees neurasthenic syndromes with vegetative disturbances were noted. In 28 %

the abnormal EEG record was found. The record of the surface leads was characterized by

a low voltage, but still of the normal alpha type or flat, and in the record of the deep leads

there appeared single short series of slow theta waves. Most of the employees of furniture

industry by operating of generators for glue wooden elements, exposed to longer waves:

7-30 MHz frequency and 30-200 V/m intensity, and contemporaneously exposed to noise (80-

110 dBA), complained also the same symptoms: headaches, excessive irritability, increased

perspiration, discomfort and sleep disturbances. No focal changes in the central nervous

system were found in these subjects. The perceptivity in most subjects was weakened, the

reaction time prolonged, psycho-motoric excitability increased. In EEG examination in 69

% the abnormalities in bioelectrical activity of the brain were detected. The record of the

surface leads was in most cases a low voltage of alpha type or flat.


In the record of the deep leads the high voltage activity was found and also numerous series

of slow theta waves and single sharp waves ("spikes") irregularly distributed, sometimes

with phase opposition. In conclusion it is suggested, that combined exposition to noise and

to electromagnetic fields, even if not very intense, and meets in general the actual safety

standards, influences adversely general health condition and particularly the brain

bioelectrical activity. The frequency of anomalous EEG records and the intensity of EEG

changes were markedly higher among furniture industry workers than among radio and

television employees, not exposed contemporaneously to noise.

[36] RESULTS OF EPIDEMIOLOGICAL STUDIES OF EFFECTS OF COMBINED

PHYSICAL FACTORS ON HEALTH STATE

Enderlein G1, Ruppe K2

1Central Institute of Occupational Medicine, Berlin, German Democratic

Republic 2Institute of Occupational Medicine, Humboldt-University Berlin, Berlin, German

Democratic Republic

The assessment of simultaneous effects of combined factors at workplaces on the health of

the exposed workers is difficult. There is only little knowledge of possible interactions between

multiple workplace-factors. It does not permit an ultimate statement in regard to health risks.

Well controlled studies on the effects of combined factors under laboratory conditions had

shown synergistic effects of noise and whole-body vibration upon hearing (TTS) and mental

performance. The most important result of our study has been a strong influence of inter indivi-

dual different reactions to the effects of the combined exposures. With the aim of studying

possible longtime effects of combined factors on workers’ health, we used the results of

periodic medical examination of workers exposed to noise (over the level of 85 dBA), to

whole-body-vibration, to hand-arm-vibration, to extreme heat, and to fibrous dust. We have

found, in relation to the intensity of the exposures in most of combinations of factors synergistic

effects. In the group of workers who were exposed at the same time to noise and to hand-arm-

vibrations we were able to show a stronger effect on the hearing than in the group of

workers who were exposed only to noise or only to hand-arm-vibration. In the

group of workers exposed to the combination of noise and whole-body-vibration, we

discovered an antagonistic effect as far as the effect on hearing is concerned and synergistic

effect on the workers’ general health. In the group of heat and dust combined exposure, we

have found an increase in the abnormal medical findings i.e. diseases of the respiratory

system, in comparison the groups exposed to mere heat or dust, in insulation, separately. The

results were statistically significant in consideration of influences of age and sex.


[37] ARE THERE COMBINED EFFECTS OF ASBESTOS EXPOSURE AND SMOKING? RESULTS OF A COHORT STUDY IN AN AUSTRIAN ASBESTOS CEMENT FACTORY

Kundi M, Neuberger M, Haider M

Institute of Environmental Hygiene, University of Vienna, Vienna, Austria

Several studies have been published dealing with the asbestos-smoking

interaction. The results of these studies are compatible with a so-called

multiplicative model for the interaction between asbestos exposure and

smoking in regard to lung cancer risk. In the further discussion these

results have often been misinterpreted as examples of more than additive (even

potentiating) effects of these agents on the individual. The multiplicative

model, however, is the formalization of the hypothesis of independence or no-

interaction in terms of relative risks. The multiplicative model in this case

implies that the lung cancer risk due to asbestos exposure within smokers

is the same as within non-smokers. The discussion on the asbestos-smoking

interaction demonstrates the urgent need of a sound and unified

terminological basis for the description of the effects of combined

exposures. It is recommended to formulate interactions exclusively on the

appropriate effect level and not with respect to probabilities, risks or

incidences. In our case the multiplicative risk model is readily reformulated as

an additive effect model which states that both smoking and asbestos being

capable of producing lung cancer and that they act additively when exposure to

both occurs. In a historical prospective study at Austrian asbestos cement factory,

2695 employees employed between 1950 and 1981 were followed up till 1987.

Individual exposure to asbestos (mainly chrysotile) was ascertained by

inspection of the records of the factory, smoking habits by interview. The

living status was established through the general registrar, and death certificates

were inspected and recorded. Results indicate additive effects of asbestos and

smoking on lung cancer. The effect of asbestos, however, was statistically not

significantly different from zero.

[38] AN INVESTIGATION OF HUMAN RESPONSES IN CLOTHING COMFORT-DISCOMFORT SENSATIONS OF WINTER, SUMMER CLOTHING AND SPORTSWEAR

Li Y, Keighley JH, Hampton IFG

Department of Physiology and Department of Textile Industries, University of

Leeds, Leeds, UK

In order to study the psychological responses of ordinary people living in

different countries to the clothing they wear daily, an investigation of


responses to clothing comfort or discomfort sensations was carried out in

three countries (Britain, China and USA) during 1985-86. 26 sensation

descriptors relevant to clothing comfort were chosen: snug, loose, stiff,

lightweight, staticky, nonabsorbent, sticky, heavy, cold, damp, clammy,

clingy, picky, rough, scratchy, cool, hot, soft, warm, wet, prickly, itchy, chill,

sultry, tickling, and raggy. A questionnaire was used in which 191 subjects

were asked to rank, on a 6 point scale, those descriptors as they applied to the

three types of clothing. Of 465 observations obtained, 191 observations were

related to winter clothing, 187 to summer clothing, and 84 to sportswear. By

analysis of variance and nonparametric analysis of significance of differences it

was found that the ratings of most of the comfort-discomfort sensation

descriptors were significantly different between the three types of clothing

(P<0.01). Differences in the ratings of most descriptors were significant

between Chinese subjects and British subjects for summer clothing, but not

for winter clothing or sportswear. Differences in most of the descriptors

were not found to be significant between male and female subjects for the

three types of clothing. By cluster analysis, it was found that the 26

sensation descriptors for winter and summer clothing and sportswear could

be grouped into four clusters: 1 (picky, rough, scratchy, prickly, itchy,

tickling, raggy, heavy, staticky), 2 (sticky, damp, nonabsorbent, wet, clammy,

clingy, hot, sultry), 3 (warm, soft, snug, loose, lightweight),and 4 (cold, cool,

chill, stiff).

[39] CALCULATION AND USE OF PROBABILISTIC SAFETY COEFFICIENT IN HYGIENIC STANDARDIZATION OF SEVERAL FACTORS' COMBINED EFFECT

Dobrovolsky LA1, Svatkov VI2

1Kiev Research Institute for Labour Hygiene and Occupational Diseases, Kiev, USSR 2Kiev Research Institute for General and Municipal Hygiene, Kiev, USSR

Today hygienic standard setting of occupational and communal environmental factors is based

on their isolated hazardous effect when we use an expert safety coefficient resulting from an

arrangement between specialists. Safety coefficient is meant to be a divisor of chronic isolated

action threshold. The result of the division represents a MAC (MAL) maximal allowable

concentration (level) of a factor. The MAC (MAL) thus obtained is liable to ignore the possibility

of the reglamented factor's combined effect with the other ones in a real occupational and

communal environment. In order to get rid of this shortcoming we propose in every separate

case to calculate the safety coefficient basing on the objective information. The latter includes, on

one hand, information on chronic combined exposure to a reglamented factor and,

on the other hand, on the reglamented factor's specific weight in the occupational or

communal environment. Under such an approach, the safety coefficient remains also the chronic

threshold divisor, the division producing a MAC (MAL) of the factor's combined effect.

Nevertheless, the MAC value has another meaning in this case: the MAC (MAL) of a factor

reglamented anew is to take into account the supposition about the possible toxicity of the sum


of MACs (MALs) of all the factors supposed to have their share in the combined effect which

should not exceed the toxicity brought forth at the level of the chronic threshold

of a single factor's isolated effect. This approach does not assume the reglamented factor's

combined effect in a real occupational or communal environment to be obligatory; it assumes

just a certain probability of such an effect. That is why the safety coefficient developed is called

probabilistic (PSC). The information necessary for its calculation is also to be

expressed through probabilities: the one of toxic changes under combined exposure to

chronic threshold concentrations of factors and the one of the reglamented factor's allowable

appearance in a real communal or occupational environment. The chronic threshold logarithm

divided by the PSC yields the PMAC (probabilistic MAC) logarithm of the

reglamented factor's combined effect.

[40] COMBINED EFFECT OF THE CNS PHARMACOLOGIC ACTIVATION

AND OF INTELLECTUAL TASKS COMPLEXITY UPON OPERATORS

Navakatikyan AO, Grigorus AG

Research Institute for Labour Hygiene and Occupational Diseases, Kiev, USSR

Three activation levels have been modelled under laboratory conditions; a

moderately decreased one (aminazine intake), an ordinary level (without pharmacologic

impacts), a moderately increased one (caffeine intake). The tested subjects have been per-

forming their work: 1) free pace, 2) in a forced regime, the low, medium and

high working pace alternating, and 3) at one of said paces during the whole of the

experiment. The duration of the experiments made up 3 hours. The task of the

tested subjects was to recognize quickly and correctly photic stimuli, both requiring and

not requiring a response. We registered R-R intervals of ECG, arterial blood pressure, time

of pulse wave propagation through the arteries, GSR integral, indices of short-term

memory, attention, muscular strength and endurance, number of tasks fulfilled, latent

response periods, and errors of task omission and of incorrect response. The results of the

investigation have been analyzed with the help of mathematical statistics methods, inclu-

ding the two- or three-factor analysis of variance. The analysis of data relative to

the forced pace testifies to the selective effect of said factors through different working

periods upon body's functions. During the first 20 minutes of the work the CNS activation

effect tells upon the cardiovascular systems functioning (effect share 65 to 90 % in

different tested subjects). Later on, the activation effect tells upon the response speed (this

factor’s effect share reaches toward the end of the experiment 37 to 76 %). Changes of

the vegetative nervous system activation, according to the GSR data, had considerable indi-

vidual differences. The most substantial effects upon psychophysiological indices among

the factors of activation, intellectual load and work duration all through the investigation,

were proper to the first two ones; the effect of work duration has been shown to be true

for indices muscular strength and systolic pressure only.


Under a free pace of work the effect of three studied factors was little pronounced. Thus,

the effect of CNS and intellectual load activation upon humans depends upon the

regime of the operator's performance. It has a particular importance for a forced working

pace. The application of variance analysis during the investigation of the combined effect of

CNS and intellectual load activation provides enough information the effect of factor

operators are exposed to.

[41] EXTENSION OF THE ADDITIVE MODEL WITH THE UTILIZATION OF SET

AND THE RESULTS IN THE FIELD SURVEY

Sakurai Y2, Matsubara N1, Noguchi T2, Horie G2

1Department of Housing and Design, Faculty of Living Science, Kyoto Prefectural

University, Kyoto, Japan 2Department of Architecture, Faculty of Engineering, Kansai University, Osaka, Japan

We have been studied the combined environment of heterogeneous factors noticing that

there always exist several factors in a room. Since a scale specific to one factor

would not express the total effect of several factors, a nonspecific scale has been

used. The method to express the degree of uncomfortableness as a linear combination of the

weight score which was obtained with the Second Method of Quantification of each

environmental factor was proposed, the method to predict the degree of

uncomfortableness in the actual combined environment and its application to the

environmental design was discussed. Thermal environment has been categorized

by dry bulb temperature (DBT; see another article in this publication). This paper aims

to discuss the possibility to extend the additive model of synthesized evaluation with the

utilization of standard effective temperature (SET). To realize different thermal condition,

only DBT and relative humidity (RH) were controlled. The results showed that the success

rate of the prediction was virtually the same as that of the past where RH was fixed. And

the quantified weight scores of each environmental condition were also similar to the

past. The reason why there is a slight different score profile was caused by the slight

inner correlation between the environmental factors. Quantified weight scores for three

environmental factors where thermal, noise and illumination environment are categorized by

SET, Leq and lx, respectively, are obtained on "uncomfortableness" scale. After all, it is

suggested that the additive model is to be extended by introducing SET. Then it is

discussed how the success rates of the prediction of residents' responses in the actual

offices would coincide with those findings obtained in the experimental chamber.

The surveyed offices were three; one was a not air-conditioned office in a university

and the others were the air-conditioned offices in companies. Reasonable results

were obtained, in spite of other factors which were not treated on the quantification.


[42] EFFECT OF ALCOHOL CONSUMPTION COMBINED WITH OTHER

FACTORS ON BLOOD PRESSURE OF MALE METAL WORKERS

Honda R, Ishizaki M, Nogawa K, Yamada Y, Kido T, Tsuritani I

Department of Hygiene, Kanazawa Medical University, Kanazawa, Japan

Factors affecting blood pressure were studied on 1897 male workers in a metal-

products producing factory. Age of workers varied between 35 and 59 years.

The variables(factors) used in the study were as follows; the questionnaires for

drinking habits and family history of hypertension, age, height, weight, blood

pressure, hemoglobin, hematocrit, red blood cell count, white blood cell count,

serum levels of GOT, GPT, γ-GTP, total cholesterol, β-lipoprotein, HDL-c,

triglyceride, uric acid, creatinine, sodium, potassium, calcium, phosphorus,

chloride and glucose. Drinking level, age, family history of hypertension and

body mass index (BMI) were demonstrated by the multiple regression analysis

and revealed them to be the significant determinative factors for blood

pressure. Drinking level also showed a close association with both systolic and

diastolic blood pressures. In addition to these determinative factors, variables

were selected from hematological and biochemical data. In the systolic blood

pressure model, the selected significant variables were age, glucose, family

history of hypertension, phosphorus, BMI, HDL-c, γ-GTP, urinary protein,

white blood cell count, red blood cell count, sodium and GOT. In the diastolic

blood pressure model, the selected significant variables were age, hematocrit,

family history of hypertension, BMI, HDL-c, γ-GTP, sodium, chloride, glucose,

triglyceride, urinary protein, GPT and drinking level.

[43] COMBINED EFFECTS OF ENVIRONMENTAL FACTORS IN A NEW CABIN

OF SUGAR COMBINA

Serralta O, Felipe M

Work Protection Institute, CETSS, Havana, Cuba

The present work includes a summary of the most important results achieved in

the 12 years of research in work environmental factors which act, in combined

form, upon agricultural machinery operators, and, especially, their

consideration in relation to the design and construction of cabins. These should

improve work efficiency and protection in sugar combines used in countries

with subtropical and tropical climates which make the sugar cane harvest

environment much more hostile, and its influence on prevailing conventional

solutions.


For example, the micro-climate treatment in our case is applied with combined

forced injection and extraction allowing for devices and measures against the

radiating action. Thus, below critical levels are to be achieved for this kind of

work. The study also deals with the application of a set of norms and proce-

dures having as ultimate aim the knowledge of work environmental factors and

its interaction with the machine operator during land exploitation as a previous

step for evaluation; laboratory experimental tests and inclusion of parameter

design to be guaranteed in the project and cabin construction for the use of this

kind of machines giving conclusions related to: 1the evaluation in cabin design

based upon an integral approach of the factors under study, 2the evaluation of

environmental factors present in the worker’s post individually and combined,

and 3the possible classification and homologation of both parts and devices in

order to attain rationalization in its application self-propulsating machine lines

in similar work environment in general.

[44] COMBINED EFFECTS OF LOCAL VIBRATION AND COLD EXPOSURES

ON DOPAMINE TURNOVER IN THE RAT BRAIN

Nakamura H1, Nohara S1, Ohnishi T1, Nakamura H1, Sakamoto M2, Okada A1

1Department of Public Health, School of Medicine, Kanazawa University, Kanazawa,

Japan 2Department of Environmental Hygiene, School of Pharmacy, Hokuriku University,

Kanazawa, Japan

Both vibration and cold stress have been well known to be ones of stressors that

cause an imbalance of the homeostasis of organisms. In order to clarify the

mechanism in the central nervous systems (CNS) that combined stresses of

vibration and noise produce more dysfunction in the autonomic-neuroendocrine

systems than each stimulus alone, dopamine (DA) turnover rates which is well

known to be most sensitive to stress, were examined in the regional rat brain in the

following 4 groups: 1) Group restrained in special cage as a control of group 2 and

group 3, 2) Group with its hind limbs exposed to vibration at 120 Hz under

acceleration of 4 g for 90 minutes, 3) Group kept in cold room (4°C) for 90

minutes, and 4) Group exposed to these combined stimuli for 90 minutes.

Simultaneously plasma corticosterone (CORT) concentrations and gastric ulcer

formation were examined as autonomic-endocrine function. The results were as

follows: 1CORT and DA turnover rate (homovanillic acid (HVA) and/or (HVA/DA

ratio)) in the frontal cortex (FC) in vibration group increased compared to that of


control group, 2CORT, ulcer formation and DA turnover rates in FC and the

nucleus accumbens (NAc) in cold exposure group were increased compared to that of

control group, while DA turnover rate in the hypothalamus (HYP) was decreased, 3CORT and DA turnover rate in FC in group exposed to combined stimuli were increased

as compared to that of cold exposure group but DA turnover rate in HYP were

decreased, 4There were no significant differences in any items examined between cold

exposure group and combined stimuli group, and 5There were no significant

changes DA turnover rate in the striatum or amygdala between any group. These

results show that the appearance of the combined effect on CORT deeply related to

DA turnover in FC increased by the combined stress, that is, psychological stress induced

by emotion which is something common to these physical stress, and indicating

mesocortical DA neuron innervating to FC plays a part in regulation pituitary-

adrenal system.

[45] INTERACTION OF NOISE AND VIBRATION

Byrne C, Henderson D

Department of Communicative Disorders and Sciences, State University of New

York at Buffalo, Buffalo, New York, USA

Whole body vibration has been suggested to be a potentiating agent in the

condition of noise induced hearing loss. These experiments were designed to

evaluate the effect of vibration frequency and acceleration in the interaction of

noise and vibration. Three groups of chinchilla were used as subjects and

hearing was monitored using an evoked response recorded from a chronic

electrode in the inferior colliculus. The first group (n=6) received an octave band

of noise (octave band centered at 500 Hz) at 100 dB SPL for 6 hours per day for

20 days. The second group received the same noise for 10 days and on day 11

vibration was added (14-20 Hz at 0.l g rms) and at day 16 the level was

increased to 1.0 g rms. The third group had the same exposure sequence as the

second, but the vibration frequency was 63-89 Hz. The vibration frequencies

were chosen to approximate either the body resonance (14-20 Hz) or the head

resonance (63-89 Hz); however, it is difficult to specify a single resonant

frequency where the body is composed of multiple spring/mass systems. The

noise produced approximately 25 - 40 dB hearing loss across the frequencies

tested. The addition of the low frequency vibration did not increase the hearing

loss, but like high frequency vibration increased the hearing loss on the average

of 4 to 8 dB across most frequencies tested. The results are discussed in terms of

agents that potentiate the effects of noise.


[46] THE INFLUENCE OF WHOLE BODY VIBRATION ON NOISE-INDUCED HEARING LOSS, A REVIEW OF ANIMAL EXPERIMENTS

Hamernik RP, Ahroon WA, Davis RI

State University of New York at Plattsburgh, Auditory Research Laboratory,

Plattsburgh, New York, USA

There is the suggestion in the literature that vibration may potentate the effects of

noise and may pose an increased risk of hearing loss. However in human

experimental studies, which be necessity are limited to low levels of TTS, the

effects measured are consistent but relatively small. A very limited number of

animal studies have also shown an enhanced hearing loss, but the scope of these

studies is limited by a large inter subject variability and small number of subjects.

Also, the high levels of stimulation that were used in some of these animal

experiments were not realistic. Our recent animal studies (chinchilla) have

used a 30 Hz, 3.0 g (rms) cage vibration in combination with continuous noise

(95 dB, 0.5 kHz octave band) and impact noise (114, 119 or 125 dB peak SPL)

exposure paradigms. All exposures lasted for five days. The impact noise

exposures were designed to have an equal total energy. Temporary (compound)

and permanent threshold shifts were measured using evoked potentials. Sensory

cell populations were evaluated with the surface preparation technique. The

results obtained from each of the above paradigms were consistent in showing that

the presence of vibration did not have a statistically significant effect on hearing

thresholds. A parallel set of experiments using a 20 Hz, 2.0 g (rms) vibration is in

progress. Preliminary conclusions are essentially the same as those of the 30 Hz

experiments. The suitability of the chinchilla as an animal model for use in vibration

experiments will also be discussed.

[47] COMBINED EFFECTS OF NOISE AND CISPLATIN

Gratton MA, Salvi RJ, Kamen BA, Henderson D

Hearing Research Laboratory, State University of New York at Buffalo, Buffalo,

New York, USA

One of the most promising chemotherapeutic agents for treating certain types of

cancer is Cis-diamminedichloro-platinum (cisplatin). Unfortunately, one serious side

effect of cisplatin is that it can cause hearing loss, with the incidence of ototoxicity

ranging from 23-61 %. One environmental agent that could potentially exacerbate

the ototoxic effects of cisplatin is high level noise exposure. To determine if intense


noise exposure could exacerbate the ototoxic effects of cisplatin, a series of

experiments were carried out using three groups of chinchillas. Group I was

exposed only to noise on days 1-5, 8-12, and 15-19 (octave band noise centered at

0.5 kHz at 100 dB SPL). Group II was given only cisplatin (2.75 mg/kg) on days 6,

7, 13 and 14. Group III received both the noise plus cisplatin as described above.

Group I, given cisplatin alone, showed little or no TTS whereas Group II,

exposed only to noise, developed 35-50 dB of TTS. By contrast, Group III, which was

given both noise and cisplatin, showed approximately 15 dB more TTS than

either Group I or II. There was some recovery in hearing sensitivity; however, the

permanent effects of the three treatments were significantly different. Group III

showed 15-50 dB more PTS at the high frequencies than either Group I or II.

Furthermore, Group III showed substantially greater hair cell loss than either

Group I or II. These results suggest exposure to intense noise during the time of

cisplatin treatment may substantially increase the risk of sensorineural hearing

loss.

[48] PREDICTION OF SYNERGISTIC EFFECTS OF ENVIRONMENTAL AGENTS ON AUDITORY FUNCTION

Fechter LD

Department of Environmental Health Sciences, Johns Hopkins University School of

Hygiene and Public Health, Baltimore, Maryland, USA

The identification of synergistic interactions between environmental factors is

tremendously accelerated when a hypothesized basis for the interaction can be

identified. We are interested in the vulnerability of the auditory system and, in particular,

the inner ear, to disruption in oxygen delivery or oxidative metabolism. Initial studies

with carbon monoxide showed that the ear is relatively well protected from this agent

due to the elevation in cochlear blood flow which accompanies carbon monoxide

exposure. Only transient auditory dysfunction as measured by a depression in the

cochlear action potential was observed. We report here on the results of more recent

studies in which rats were exposed to noise concurrently with carbon monoxide.

We anticipated that carbon monoxide might be able to potentiate permanent noise

induced threshold shifts and auditory injury because of evidence that noise may

serve to enhance cochlear metabolism and decrease cochlear blood flow. We

anticipated that concurrent carbon monoxide exposure would limit cochlear oxygen

delivery and predicted that a synergistic relationship would be found using combined

exposure. We have evaluated both the effects of carbon monoxide dose and of the

frequency characteristics of the noise upon auditory function across the rat's

audiogram. In these experiments auditory thresholds were assessed behaviorally using

reflex modification audiometry.


Rats were then assigned to groups which received noise alone (2 hours), carbon

monoxide alone (3.5 hours), combined treatment (90 minutes carbon monoxide and 2

hours noise and carbon monoxide) or no treatment (control group). After an interval

of 1-6 weeks behavioral thresholds were measured again. In some experiments, light

microscopic examination of the organ of Corti was performed. The results show

profound potentiation of noise induced injury by carbon monoxide at levels as low as

500 ppm for 3.5 hours. Both behavioral and histological data also suggested a

preferential high frequency injury under combined exposure when broad band

noise was used. However, when octave bands of noise are presented, there is evidence

that the point of maximal disruption of cochlear function shifts in relationship to the

characteristics of the noise exposure. Thus it appears that the physical characteristics

of the noise determine the locus of injury along the cochlea. [49] HAEMATOLOGICAL AND SEROLOGICAL DEVIATIONS IN RATS AFTER

EXPOSURE TO COMBINED ORGANIC SOLVENTS

Zastrow G, Diehl HA

Biophysics Group, FB1, University of Bremen, Bremen, Federal Republic of

Germany

Rats were exposed to methoxyethylacetate (25 ppm), to methylisobutylketone

(200 ppm) and to nine different combinations of them with toluene (200 ppm),

xylenes (100 ppm), ethylbenzene (100 ppm), isobutylalcohol (100 or 300 ppm)

and isobutylacetate (200 or 600 ppm). These solvents are the main components

in spray painting lacquers. They are known for their occupational toxicity. It is

desirable to find, in vivo, available parameters which may indicate if certain

combinations of those solvents interfere with their physiological effects. The

urine metabolites of the organic solvents used are no good indicators (see

accompanying paper here). So blood parameters are to be looked for whether

they might indicate combination effects. Exposure lasted four or twelve weeks

and eight hours daily during the active period of the rats. One day after the last

8-hour exposure the following parameters were determined from the blood and

the blood sera (respectively) of the animals: hematocrit value, hemoglobin

content, erythrocyte number and the total protein content. The serum proteins

from some exposed groups additionally were further analyzed by

electrophoretic methods. The most distinct deviation from normal values with

respect to all parameters measured was obtained after exposure solely to

methoxyethylacetate. In combination studies there is a clear tendency to a

diminished deviation. In immunoelectrophoregrams five different proteins can

be shown to be involved in solvent effects: α1-antitrypsin, α1-lipoprotein and

one component of the complement system, two other proteins are unidentified

so far.


[50] AN IN VITRO METHOD FOR EVALUATION OF THE NEUROTOXIC EFFECT OF INDUSTRIAL SOLVENT MIXTURES

Tähti H, Korpela M

Department of Biomedical Sciences, University of Tampere, Tampere, Finland

In industry, organic solvents are mainly used as solvent mixtures. Thus

occupational exposures to solvents often mean exposure to solvent mixtures.

Industrial solvents have s general narcotic effect on the central nervous system

(CNS). This effect is based on a membrane fluidity change due to solvent

exposure. In our previous studies we have shown that the membrane effect occurs

under concentrations which are subanesthetic and even lower than the

accepted threshold limit values. We have measured the membrane changes by

studying the integral enzymes acetylcholinesterase (AchE) and ATPase in

erythrocyte membranes and in synaptosomes isolated from rat brain. The in vitro

model has been compared to results obtained in an acute inhalation exposure of

rats to toluene. The results show that the in vitro models can be applied to

predict the possible hazardous neurotoxic effects of organic solvents and solvent

mixtures. The mixtures of aromatic hydrocarbons, chlorinated aliphatic

hydrocarbons, and a commonly used admixture of n-hexane, ethylacetate and

toluene were tested. The cell membranes were incubated within buffer with known

solvent concentrations. The activities of the membrane integral enzymes were

determined and calculated per mg protein. The activities in test samples were

calculated as per cent activities of control samples. The most prominent effects

were found in the combinations of aromatic hydrocarbons (toluene, benzene,

xylene, styrene). The combinations of chlorinated aliphatic hydrocarbons

(trichloroethylene, 1,1,1-trichloroethane and 1,1,2,2-tetrachloroethane) were not

more effective than the most effective solvent in the mixture. The admixture of n-

hexane, ethylacetate and toluene seemed to be quite safe, causing nearly the same

effect as toluene on integral enzymes in the membrane preparations. We consider

the erythrocyte model and the synaptosome model to be suitable in studies on the

CNS effects of organic solvents and their mixtures.

[51] DIFFERENT EFFECTS FROM INHALATION OF COMBINED ORGANIC SOLVENTS

Diehl HA1, Oelkers B1, Kaschny P1, Braun H1, Störmann R2, Schill W3, Jastorff B2

1Biophysics, Physical Department FB1, 2Bioorganic Chemistry, Chemical Department

FB2, 3Mathematical Department FB3, University of Bremen, Bremen, Federal

Republic of Germany

Rats were exposed to seven different organic solvents and eighteen different combinations of

them. Exposure occurred for 12 weeks and eight hours daily during the active period of

the rats at concentrations in the range of the threshold limit value of each

organic solvent: 200 ppm toluene, 100 ppm xylene, 100 ppm ethylbenzene, 100 ppm

isobutanol, 200 ppm isobutylacetate, 25 ppm methoxyethylacetate, and 100 ppm


methylisobutylketone. These solvents are main components in spray painting

laguers. They have been chosen on behalf of their partly common and partly different chemical

properties. During the exposure period the development of body weight, the

motional activity of the animals and the urine concentration of the main metabolites of the

inhaled organic solvents have continuously been registered. One day after the last 8-hour

exposure the rats were decapitated and some organs were prepared for

biochemical or histologic investigations. Especially those liver parameters were

explored which characterize the detoxification capability the microsomal monooxygenase

system has been checked with respect to its de-ethylation activity against the standard substrate 7-

ethoxycoumarin and with respect to its side chain as well as ring oxidation of the

organic solvent molecules themselves. The alkylbenzenes influence all indicating

parameters into the same direction with increasing potency from the xylenes to

toluene to ethylbenzene. No specific combination effects can be detected. The main urine

metabolites of the alkylbenzenes (hippuric acid, benzoic acid, methylhippuric acids

as well as others) turn out to be no reliable indicators for specific alkylbenzene

loads and should be doubted as a base for establishing biologically acceptable tolerance

values. Those animals which have been exposed to all three alkylbenzenes

simultaneously for longer than one month do not reach the motional activity of the control

groups even not in the day time period without exposure. This effect vanishes if the

alkylbenzene is co-inhalated with the aliphatic organic solvents as indicated, what itself causes no

motional depression with the distinct exception of methoxyethylacetate. This solvent causes

an accumulating depression of motional activity. So, we are concerned with the

fact that component A solely and component B solely cause an effect, but not

the combined factors A+B. Some mechanistic hypotheses of the combined acting organic

solvents will be discussed. Main targets as metabolizing systems are esterases,

alcohol/aldehyde dehydrogenases, the liver microsomal monooxygenase system and the so

called phase II conjugating systems.

[52] COMBINED EFFECTS OF CADMIUM AND COPPER ON

CATECHOLAMINES IN RAT BRAIN

Sakamoto M1, Sakai T2, Nakamura H3, Nohara S3

1Department of Environmental Hygiene, 2Department of Pharmacology, School

of Pharmacy, Hokuriku University, Kanazawa, Japan 3Department of Public Health, School of Medicine, Kanazawa University, Kanazawa,

Japan

It seems important to study its interaction with some metals exposed in the polluted

areas. The present study was examined to clarify the relationships between metals

(Cd, Cu) and catecholamine in brain of rats.


24 rats were divided into eight groups. Female rats were given a diet containing both

cadmium chloride (Cd 3, 10, 30μg/g) and copper sulfate (Cu 200 μg/g) to group 1-3 or

copper sulfate alone to group 4 or cadmium chloride alone to group 5-7 for 180 days.

Rats were sacrificed by decapitation at 24 h after the last feeding. Metals in tissues

were determined by atomic absorption spectrophotometry. Catecholamines in the

brain region were analyzed by using a high-performance liquid chromatography

system with a cation exchange column and electrochemical detector. As a main result,

cadmium and copper greatly enhanced the accumulation of cadmium in liver, kidney

and brain of rats. Exposure to cadmium alone decreased content of norepinephrine

(NE), epinephrine (E), 3-methoxythyramine (3-MT) and serotonin creatinine (5-HT) in

brain cortex. Dopamine (DA), norepinephrine and epinephrine decreased by

combined exposure to cadmium and copper. Increases of the body weight were

suppressed by exposure to cadmium and/or copper. Therefore, this study suggest that

the combined exposure of cadmium and copper, and cadmium alone exposure

induced the increase of cadmium and the decrease of biogenic amines in brain of rats.

It indicates the relationship between cadmium and catecholamine in brain of rats.

[53] SUBSTANCE P AND TOLERANCE OF FEEDING AND ESCAPE TO ETHANOL IN THE RABBIT

Zilov VG

Department of Normal Physiology, IM Sechenov First Moscow Medical

Institute, Moscow, USSR

Some of brain peptides were found in recent studies to enhance tolerance of an

organism to ethanol. The goal of the present investigation is to examine the

ability of substance P (SP) to enhance tolerance of central mechanisms, both

feeding and escape, to ethanol (E). Rabbits were treated (iv.) with 0.5 g/kg E and

alterations of limbic-midbrain interactions as well as excitabilities of lateral (LH)

and ventromedial hypothalamus (VMH) were observed. Decrease of the

VMH excitability and abolishing of inhibitory effects of the dorsal

hippocampus (HpC) and facilitating influences of the midbrain reticular

formation (MRF) on both motivational hypothalamic centers were found in animals

after ethanol administration. Subsequent single injection of SP (30 μg/kg) (just in

the heat of deleterious E-effects in central mechanisms of motivated behaviors)

led to restoration in 72.2 % of the VMH-excitability and in 90.3 % facilitating

MRF-influences on this motivational center (p<0.01). SP had no effects on LH-

excitability which was also not touched by previous E-injection. However, SP

restored in 88.8 % the inhibitory HpC-effects on excitability of LH which were

abolished by E. In 66.7 % of observations SP-injections were found to restore the

facilitating MRF influences on excitability of feeding center.


SP-effects were also analyzed in experiments with escape reaction when this

peptide was administered before E-injection. It was found that after SP ethanol-

injection in 93.3 % of cases did not change the excitability of VMH and in 86.7 %

did not abolish facilitating MRF-effects on this motivational center. Partial and

selective SP-restoration of ethanol-induced alterations in feeding and escape and

partial preventive SP-role of deleterious E-effects in escape let to suggest

that this oligopeptide could be understood as a factor enhancing tolerance of

central mechanisms of some motivational behavioral reactions to ethanol.

[54] PHYSIOLOGICAL FAILURES PERMITTING DEBILITATING STRESS

Brooks CMcC

Department of Physiology, State University of New York Health Science Center,

Brooklyn, New York, USA and Center of Theological Research, Princeton, New

Jersey, USA

Study of the action of and reactions to stressors that may ultimately result in

debilitating stress requires consideration of powers of adaptation to as well as the

effects of situations and stimuli that can cause stress. Another requirement is the

recognition that the body is an integrated unity; stimuli have special significances

and evoke specific reactions but the total body is affected by any and all

impingements. Similarly there are specific responses evoked by stressors but the total

body is involved in any reaction. Stress is usually defined as resulting from the

encountering of forces that cause a threat to or a degree of failure of the integrative

functions that maintain essential balances - failures of homeostatic states. Although

the cerebral cortex of the brain, cerebellum, subcortical structures, the mind and spirit

of man are involved, the initial reacting systems, the hypothalamus, midbrain and

medulla, have primary governance over the autonomic nervous system, the

neuroendocrine system and the exocrine - endocrine complexes which are involved

in emotional, intellectual and physical components of the responsiveness.

Individual animals as well as individual men vary in their resistance to stressors.

This is due in the case of man, not only to genetic heritage but also to cultural

backgrounds and past experiences. Recent recognition of the actions of neurally

liberated humors transmitters, peptides, opioids etc. has contributed much to studies

of stress and its modulation. The body mounts lines of defense, when they do not

suffice to obtund the effects of stressors then injury occurs and pathological

consequences result. What is the strongest defense against injurious stress?


[55] "QUANTUM" OF HUMAN PHYSIOLOGICAL STATE AND ITS POLYMETRIC ANALYSIS

Fudin NA, Dmitrieva NV, Badikov VI PK Anokhin Institute of Normal Physiology, USSR Academy of Medical Sciences, Moscow, USSR

Functional system theory approach allows us to postulate the existence of

behavioral "quantum" which could be taken as a unit of behavior. Basing on this

approach an express method of ecological medical observations analyzing the

functional state of workers in real industrial conditions was proposed. A special

system of polymetrically recorded indices, including the most informative

integral parameters of ECG, RVG, EMG, arterial blood pressure, respiratory rate

and temperature to characterize various classes of the functional state was

developed. Multivector compound "quantum of state" on the matrix, using descrip-

tion of basis of the whole set of physiological parameters, was demonstrated. An

analysis of deviations in physiological parameters during industrial activity in

correlation with basic stages of adaptation syndrome was done. For this purpose

a method of permanent correlation of the "quantum of state" with previously

estimated standard pattern has been developed. The method of correlation in

"quantum of state" was tested while studying 280 industrial workers at their

working places.

_______________________________________________________________________________________________________________________________________________________________________________________________________________________________

Combined Effects of Environmental Factors: Book of Abstracts ICCEF 1988 Edited by Olavi Manninen

Research Program on the Combined Effects of Environmental Factors Tampere, Finland

Publishing Office S. Siuro, Tampere, Finland Printed in Finland by Pk-Paino Oy, Tampere, Finland 1988

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Combined Effects of Environmental Factors