Exposure to asbestos and exposure monitoring at Helsinki Asbestos 2014

© Finnish Institute of Occupational Health – www.ttl.fi 07.04.23 Timo Tuomi

Exposure to asbestos and exposure monitoring

Timo Tuomi

© Finnish Institute of Occupational Health – www.ttl.fi/en

Exposure periods to asbestos, historical perspective

07.04.23 2Timo Tuomi

* still going on in Asia-Pasific, Russia, China, Kazakhstan,Brazil, India, Pakistan, Vietnam etc


“An estimated 125 million people are exposed to asbestos at work and 107 000 people die of asbestos-related diseases every year. These diseases will increase greatly in the coming years."(WHO)



Asbestos in Finland (Rantanen et al, 2014)



War times –boosters for industrial use of asbestos• The First World War -> enormous increase in

shipbuilding -> increased the use of asbestos as fire retardants in warships.

• At that time, the dangers of asbestos to shipyard workers were not even considered.

• The Second World War -> even more asbestos use -> rise in production from that time.



The industrial use of asbestos

•More than 80% of all asbestos has been used in asbestos cement production•Insulation material•Numerous applications of asbestos containing products, ACP, and materials, ACM

About half of the asbestos put in buildings are there in place (Finland) ! ! !


© Finnish Institute of Occupational Health – www.ttl.fi/en 07.04.23 Timo Tuomi

Asbestos exposure today !

• Occupational exposure (in BAN countries):• asbestos removal workers • workers in waste handling • repair and maintenance in premises with ACM

• Environmental and domestic exposure:• maintenance and "homeimproving" activities in houses

and dwellings with asbestos containing material in structures

• after failing of dust control in asbestos removal worksite

Occupational exposure (in countries with new asbestos use/production)

The epidemics of asbestos related diseases will continue !


Asbestos minerals



Formation of fibrous minerals


MgFe

SiO

Ca Na


Asbestos minerals

Asbestos is the collective term for six naturally occurring fibrous silicate minerals


Asbestos under scanning EM6000X

• Kuvia asbestista

• Vesi ruoka !!!!


Crocidolite Anthophyllite

Chrysotile Tremolite


Exposures resulting of widespread commercial use



High exposure took place –asbestos spraying

• spraying of asbestos was one of the most dangerous forms of application

• sprayed asbestos is extremely friable, fibres are very likely to be emitted into the ambient air

• a large amount of sprayed asbestos can be found in civilian and military ships which were built using this technique.

The air concentrations of fibers during the spraying were up to 100-200 f/cm3


Occupational exposureHagelmeyer et al, 2006, Riala, 1991

1950-54 1970-74 1980 1990

Textile industry

Production of•gaskets•asb. cement•brake pads

(Germany)

10-200 5-20 1-15 0,1-2

Production of•asbestos cement•ACP•building•abatement•brake maintenance•misc. installations

(Finland)

- 0,1-80 0,1-8 0,1-1

(f/cm3)



Asbestos cement production:mean fiber concentrations in different operations



Environmental exposure to asbestos Environmental and indoor exposure today, fibers/cm3

•Outdoor, rural-urban 0,00001–0,0001•Outdoor, ind. sources 0,01 •Indoor air 0,00003-0,006

- industrial sources (asbestos mine or factory, demolition site, or improperly protected asbestos-containing waste site)- Indoor concentrations depend on indoor sources, insulation, floor tiles, ceiling etc.(ATSDR, 2001)



Exposure limit values in Finland (all asbestos types)



Current limit value, EU

• Workplace air: 0,1 f/cm3 for fibers longer than 5 µm, thinner than 3 µm and length/width > 3

• "Asbestos free air":0,01 f/cm3


Common building materials containing asbestos


Paint in outer walls Asbestos cement boardsHeating pipe insulation

Sprayed asbestos

PVC tiles and bitumen glue Insulation material, soft board and rope Fixing plaster

Cast magnesiamass (floors)


Measurement and analysis of asbestos• Airborne fibers

• during asbestos work• inside respirator• in the exhaust air of a filtering unit• after cleaning and dismantling of the enclosed area

• Settled dust (asbestos contamination) on surfaces

• floors, tables, pipe canals, inside ventilation ducts• archive folders, office papers, shelfs, etc

• Asbestos as a constituent• in building materials• in rocks, ores and soils • in water, (earlier in beverages, wine)

• Asbestos burden inhuman body• in human lung tissue, (post mortem or surgical samples)

07.04.23 Timo Tuomi


Asbestos under light microscope (disp. staining)


© Finnish Institute of Occupational Health – www.ttl.fi/en 9.10.2012

Source : Heli Lallukka/FIOH

Method of exposure measurement (air samples)

•The air concentration of asbestos fibers is determined from filter with electron microscopic counting and analysis with energy dispersive x-ray analysis (EDS) with standardized procedures. Fibers with a minimum length of 5 µm and maximum width of 3 µm and the length to width ratio of at least 3:1, are counted

Filter holder

to sampling pump

elektronimikroskooppi


Asbestos under electron microscope (SEM)

Point of the elemental analysis


Fiber 1: crushing

EDS-Spectrum of tremolite fibers from a metal ore mine

Fiber 2: crushing

Fiber 3: crushing Standard tremolite (IOM)

Source :Heli Lallukka/FIOH

samples coated with gold (Au)


Summary data from measurements after 2004 (Finland):

• asbestos fiber concentration inside respirator

• typically less than 0,01 f/cm3 (exceptions exist !!)

• air concentration during asbestos removal (outside respirator)

• sprayed asbestos, 50-200 f/cm3• vinyl tile removal 0,1–0,5 f/cm3• pipe insulation removal 2,0–10 f/cm3


Asbestos is still mined and manufactured


Concentrations of airborne fibers(> 5 µm) and dust in mining and milling (Uralasbest, 1995) (Tossavainen et al, 1999 , Am J Ind Med)

Fiber conc.SEM (f/cm3)

Fiber conc.Light micr. (f/cm3)

Dust conc.(mg/m3)

Quarry 0,08(0,01-0,27)

0,52(<0,1-2,8)

Plant No. 4 4,61(0,18-14,0)

3,62(0,11-11,6)

2,33(0,1-12,4)

Plant No. 6 0,69(0,03-5,60)

0,63(0,03-5,1)

0,83(<0,1-4,5)


”Dust levels about the same as in mines and factories in CanadaZimbabwe and India, All fibers were chrysotile” (Tossavainen et al, 1999 , Am J Ind Med)


Chrysotile fiber concentrations (>1 µm) in lung tissue of autopsy cases, Asbest Town Hospital (Tossavainen etal, Am J Ind Med, 2000)

Type of exposure

Mean chrysotile fiber conc. (f/g)

N>1x106 (f/g)

N

ChrysotileMining

8,00,9-24,5

7 * 8

Chrysotile milling and manuf.

11,62,0-50,6

11 11

Unknown occup. in chrysotile industry

13,10,8-26,3

4 5

Unknown exposure

2,60,1-14,6

13 23


* the amount of tremolite fibers was about 10% of the chrysotile fibers


ARD diagnostics and epi research: Evaluation of asbestos exposure from work history

• Interview, employment records• Probability of exposure (for studies):

• Definite, asbestos manufacture, -spraying, insulation• Probable, construction, shipbuilding,pipefitting• Possible, mining, car repair, maintenance • Unlikely, office work, education, health care, agriculture

• Counting of fiber years (cumulative dose, individual):

• Faserjahre- approach (Germany, BK-Report 2013)

• number of work days per year X mean fiber (air) concentration during work day

• work description (asbestos exposure) of different works/occupations

• example: 240 days x 1 f/ml = 1 fiber year (Germany)• 25 fiber years = lung cancer risk is doubled


Fibers stay in the lungs

• the adverse heath effects of asbestos are caused by inhalation of asbestos dust =airborne fibers

• asbestos fibers stay in the lungs and clearance is slow (chrysotile behaves differently from amphiboles)


The body burden – what we have learned of exposure and fibers in the lung (Helsinki Criteria, 1997)Highly indicative to past occupational exposure to asbestos:

•Pulmonary fiber concentration (> 1 µm):1 million f/g dry tissue or 0,1 million f/g dry

tissue (amphibole fibers)•"Asbestos body" concentration in BAL-fluid

> 1 AB/ml (BAL) or 1000 AB/g dry tissue

The relative risk of lung cancer risk is 2:

•Pulmonary fiber concentration (> 5 µm): > 2 million f/g (amphibole fibers)Pulmonary fiber concentration (> 1 µm):> 5 million f/g (amphibole fibers)5000-15000 AB/g dry tissue or 5-15 AB/ml

(BAL)


Asbestos exposure of today and tomorrow1. We have still millions of tonnes in place as

a source of exposure2. New asbestos is produced and used

• Removing all existing asbestos is a goal (EU Parliament Initiative, 2012)

• Safe removal and waste management is needed and has to be developed further

• Reliable low cost methods to identify asbestos have to be developed for countries with modest resources• Where ACM are found, what does it look like, history of

the building and material use



Thank You !

Warm thanks to Heli Lallukka, Juhani Piirainen, Panu Oksa, Jorma Rantanen

© Finnish Institute of Occupational Health – www.ttl.fi/en 07.04.23 34Timo Tuomi


Health Council of the Netherlands, 2012. Asbestos: risks of environmental and occupational exposure

Risk level OEL (TEM) corresponding to the risk level

(f/cm3)

Chrysotile Mixed (max. 20 % amphibole

100 % amphibole

4x10-3 0,2 0,13 0,042

4x10-5 0,002 0,0013 0,00042


Health & Medicine

Exposure to asbestos and exposure monitoring at Helsinki Asbestos 2014