4/12/2012 Dr. Haldar

Occupational Health Hazards & It’s Control

Industrial HealthIndustrial HygieneIndustrial PsychologyIndustrial Physiology

Institutional TrainingIn Plant Training

Occupational Study :- National & ConsultationOccupational Health Audit:- Safety & Health AuditHealth Audit:- Pre-requisite for Thermal Power PlantOccupational Health Survey:- From Competent Authority and from Outside Authority

Bernardo Ramazini:- An Italian Scientist labelled as Father of Occupational Health.

Occupational HealthOH

OD/H OEOccupational Diseases/Hazards Occupational Environment

Occupational Environment is defined as :- External Condition & Influences prevailed at the place of work which has direct & indirect effect on health of working population.

Occupational Health is the promotion & maintenance of highest degree of Physical, Mental & Social well being of workers in all occupations. It is a division of General Medicine & is devoted to prevention of Occupational Diseases & Injuries & Promotion of Health of people at work.Principles of Occupational Health:- 1) Prevention

2) Promotion:- Training of people3) Protection4) Adaptation5) Cure & Rehabilitation6) Primary Health Care

1) Prevention:- Prevention of accidents, heat stress, NIHS etc.2) Promotion:- Primacy:- Detailed training of job hazard.

Frequency:- Periodical Training.Resency:- Lay Man’s gap is big, they may forget. Thus feeding of information

Through posters, Exhibits etc. is required.3) Protection:- Personal Protective Devises (PPE)4) Adaption:- Acclimatization, cope up adjustment5) Cure & Rehabilitation6) Primary Health Care

Occupational Disease:- Disease which arises out of or in course of occupation. It is difficult to diagnose, has long incubation period, in early stage show no signs & Symptoms. In advance stage it becomes a burden on the person, family, company and on nation.

Etiological Fractions of OD:- Skin Diseases:- 45%, maximumMusculo-skeletal:- 33%Nervous:- 30%Respiratory Diseases:- 25%Cardiovascular:- 20%Mental:- 5%Cancer:- 4%, least of total cancers in the world

Skin Dise

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Musculo-sk

eletal

Nervous

Respira

tory Dise

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Cardiova

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Mental

Cancer

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Interaction in Occupational Environment:- Workers Vs Physical Agents

Chemical AgentsBiological Agents:- e.g. Mosquito bite

Workers Vs MachinesWorkers Vs Workers

Types of Hazards:- 1)Physical 2)Chemical 3)Biological 4)Mechanical:- Accidents, Injuries & 5)Psychological 1) Physical Agents:- 1) Heat :- erethema abegnie(?):- brownish discolouration

2) Cold:- Ice forming freezing, Non ice forming freezing. Used for generalized shipment preservation. Causes Local:- Frost bite;- Superficial (only skin effect, Deep:- Internal tissues involved, Thawing, immersion feet / Trench feet 3) Noise 4)Vibrations:- Hand drum vibrations (8 Hz/sec White Fingers, Renold’s Phenomenon 5) Ionizing Radiation(Penetrate tissues & deposits its energy (Alpha, Bata & Gamma) 6)Non Ionizing Radiation:- UV rays, Infra Red Rays (Immediate-sickness, Delayed :- Somatic- carcinoma, Leukaemia, Genetic:- Chromosomal Point Mutation) , Micro Wave, Laser 7)Electricity:- Voltage, Path through body, duration, resistance at the point of entry & 8)Light.

9) Barometric Pressure:- High, Low. Barotraumas- Kolar Gold mines – Compression Barotrauma affects ears, eyes, joints. Barometric Pressure at sea level is 100 KPa. At pressure 7,000 KPa symptoms starts.Decompression Syndrome:- air embolism due to Nitrogen bubbles during decompression. V = P X T10) Ultrasonographic (USG):_ Long term exposure causes disintegration of tissues, which mainly affects RBCs leading to Anaemia11) Electromagnetic Field (EMF):- Unit of EMF is Tesla:- Permitted 1uT. Causes Cancer, Reproductive problems:- Males:- Brain TumourFemales:- Foetal Developmental abnormalities, Miscarriages, abortions, Psychological:- Suicidal TendencyNo effect on heart but causes disturbances t pace maker.12) Moisture13) Colour:- Ceiling white, Red is freshening14) Fire:- Emit about 400 toxins, Chemical Asphyxiants (CO, H2S, HCN), CO2 is simple Asphyxiant:- stimulates respiratory centre causing increasing depth & rate of respiration, thus more amount of toxic gases are inhaled. Thus indirectly helping toxicity of other asphyxiants.Welding:- Flash / Arc Eye:- due to UV rays- Redness, watering, foreign body sensation, diplopia- 48 Hours of rest needed.15) Barotrauma:- Barometric Pressure High or low

Model Rule (A + B) / 2 = anteroom (?)

Metal Fumes Fever:- While welding fumes of metals like Zn, Cadmium, Aluminium (metal fumes containing Al & Cadmium):- Flu like symptoms lasting for few hours, sometimes breathlessness & asthma.

Mill Fever:- Exposure to cotton, flax or hump:- Fever, non productive cough, malaise, sneezing, which lasts for few hours, due to endotoxins from Gr.-ve bacteria contaminating cotton.

Bagasosis:- Acute Monday fever due to delayed hypersensitivity (Pl. Check)

2) Chemical Agents:-

Dust Gases Metals & their Fumes Solvents Chemicals

Organic inorganic AcidSugarcane Silica AlkalisHay Coal Organic

Asbestos

Irritants Asphyxiants Drugs Like(Heart of Total Hazards)

Primary Secondary Anaesthetic Solvents HydrocarbonAffecting Secondary Ether ChloroformSite of to absorption BenzeneAbsorption gives Systemic Toluene

effects OR Simple Chemical

Water Water CO2 COSoluble Insoluble Methane, H2S(Readily) ( Slightly Hydrogen HCN

Soluble) Aniline

Dust:- Silica, Nascent:- Chalk DustAsphyxiants:- Does not allow body to utilize OxygenCement:- Dermatitis, Burns & UlcersOil:- Contact Dermatitis, Oil AcneAsbestos:- Crocidolite Asbestos is Banned. Asbestos fibres with hemosidrin form asbestos bodies which are retained in the alveoli.Why Blue Asbestos is dangerous:- 1) It is brittle, so cause more dust leading more amount inhalation.

2) Cannot produce asbestos bodies. There is no clearance.3) edges are very sharp cause much irritation.4) Causes Mesothelioma of Pleura, Lung & GIT Cancer

Silicosis:- Many times causes Mixed dust fibrosis. Silica + Iron in steel, iron mines.Coal miner’s lungStannosis:- Tin dustLead:- Inorganic Lead:- Foot drop, wrist drop

Organic Lead:- Leaded Petrol, Tetra ethyl lead, anti-knocking agentPhenol Lead: Cause leucoderma, Bindi

Chromium:- Chrome Ulcers, holesChromium, Nickel, Cadmium, Arsenic cause Nasal Septal Perforation (Pl Check)Smoking & Occu. Disease:- Additive effect – all irritant gases

Synergistic:- Smoking + AsbestosPotentiating:- Smoking + Cotton Reducing:- Zinc, Cadmium

Coke:- When Coal is burnt produces ash. If coal is burnt without Oxygen produces coke. Coke is used in ink industry, to produce gramophone records.Silica:- SiO2 – 3 types 1) Quartz 2) Tidimi @ 800 C 3) Crystabolite @ 1200 CBoiler lining cleaning, Sand blastingDispersion Module:- SO2, Ammonia, LPG, CS2

Chemical Interaction & It’s effect on Human Body

Additive Synergistic Potentiating ReducingAll irritant Gases Smoking+ Asbestos Smoking + Cotton Zinc, Cadmium

3) Biological:- Bacteria, Viruses, Protozoa( rat, cat, dog, snake bite), Anthrax:- Cutaneous, Pulmonary Ligionella

4) Mechanical:- Accidents, InjuriesEnvironmental Human

Physical Physiological PsychologicalHeat Colour Blind Age Accident PronenessNoise Deaf Sex Over Enthusiastic

ExperienceOrientationTimingShift

5) Ergonomics:-Computer operators

5) Psychological:-Behavioural Psycho- somaticNeurosis High BPFear SleeplessnessAlcoholism Peptic UlcerDrug Addiction

Sustained Trauma Disorder (STD) / Cumulative Trauma Disorder (CTD)Work related Musculo-skeletal disordersExercise Program:- Fitness gainNutrition at work

Preventive Measures:- Medical Safety Statutory / Legislative Administrative:- acclimatization

Medical Examination :- Pre-employment, periodic, Pre-placement, Pre-retirement & SpecialNotification:- 29 (+5) notifiable diseases, compensable by Workman’s Compensation ActIf the disease is misdiagnosed by the doctor penalty is Rs. 1,000.

1) OHS Principles2) First Aid Boxes:- Factory Act chapter IV a added after Bhopal Gas Disaster.3) FA Centre4) Hospital

OHS IN India:- SupervisionMaintenanceHealth Education & Counselling

Donabedian ModelUK, US Model

Repeat audit on regular basis in order to ensure Set StandardsThat the standards are maintained

Measure / Observe Current Practices

Impose changes in order to meet Corporate current procedures & or improvements

This is a common model for Occupational Health Audit.

5/12/2012

Physical Hazards1) HEAT

Flow chart of Heat Hazards

Heat Loss by all means Woker(Radiation, Convection, Conduction, Evaporation) entering into factory

Increased Body HeatShifting of heat to periphery (higher to lower)

Heat StressLoss of Heat (Evaporation)

Heat Strain (after working for sometime)

Sweating Vasodilatation (VD)

Heat Stress:- The amount of heat that is to be eliminated from human body in thermal equilibrium & measured as metabolic Heat load & Heat Loss or Gain through the process of Convection, Conduction, Radiation & Evaporation.

Heat Equilibrium M+ (R+C+K) – E = SM = Metabolic Heat Load, R = Radiation, C = Convection, K = Conduction, E = Evaporation, S = Stored Heat / Heat StressThus equation becomes:- M + (R+C+K) – E = + S As per heat gain or loss

Heat Strain Physiological or Pathological changes of body due to heat stress.

Vasodilatation causes sweating. Upto this level heat is compensated. Loss of heat is from body surface, thus the internal heat is shifted to periphery. This is the cut off point called as Prescribing Zone.

Vasodilatation

Sweating Fluid Depletion (heat exhaustion) Loss by Evaporation

Salt Loss causing Heat Cramps Mainly Calf & Abd. Muscles Heat Hyperpyrexia

Vasodilation (Pulling blood to lower part of the body) Complete Stoppage of Sweating

Less Blood to Brain Heat Stroke(Temperature Regulating Centre

Heat Syncope Paralysed – 40% Mortality)(Thermo Regulatory centre is not paralysed)

Indirect effects :- More accidents, errors, fatigue, sleepless nights, decrease productivity.

Measurement of Heat Stress:- Heat stress can be measured by two departments 1) Medical Department 2) Hygiene DepartmentHygiene Department measures Ambient Temperature.

Medical department:- Usually a worker has 3 breaks. Take the resting pulse weight, & oral temperature. After working for maximum hours take the measurements again.

Give ½ minutes of rest, then take pulse for one full minute ( 0.5 to 1.5 min.). This is P1. Now give rest for one minute ( 1.5 to 2.5min.). Now take the pulse again. This is P3.In Heat Stress:- 1) Oral Temp. Is more than 37.5⁰C

2) P1 is more than 1103) P1 – P3 is less than 10

This all should be done at work place, called as Work Place Health Monitoring.Cooling measure is the immediate treatment. In this case rectal temp should not go below 102 F.Preventive measures:- Well ventilated rest room, Drinking water, Salt water. All measures should be at source.Acclimatization:- This is 1 to 2 week program. Actual worker’s duty is at 100⁰ F carry 100 Kg. Of load.On day 1:- Built a set up- Start with 50⁰ F & 50 Kg Weight and increase by 10 % every day. Thus on last day of the week he will have full load. From next week continue with full load. In acclimatization sweating is same but retention of salt is more and excretion of salt in urine is less. This is due to Renin – Angiotensin - Aldosteron Mechanism. Thus here excretion of salt is mainly through sweat.In Heat Stress Comfort Zone (Worker can work comfortably) depends upon 1) CET (Corrected Effective Temperature and 2) P4SR (Predicted 4hour sweat rate)

1) Corrected Effective Temperature :- This is a combined effect of 1) Ambient Temp. 2) Air Movement (Internal Air Movement should touch the skin of the worker) 3) Moisture 4) Radiant Heat. These all should be added to correct the effective temp.

2) P4SR Predicted 4 hour sweat rate:- 1 to 3 lit. S a comfort zone.

Corrected Effective TemperatureZone Corrected Effective Temperature in Farenheight

Pleasant & Cool 69⁰FComfortable & Cool 69⁰F – 76⁰FComfortable 77⁰F – 80⁰FHot & Uncomfortable 81⁰F – 82⁰FExtremely Hot 83⁰F – 85⁰FIntolerably Hot 86⁰F+

P4SR:-Zone Sweat Rate

Comfortable 1 – 3 Lit.Just Tolerable 3 – 4.5 Lit.Intolerable More than 4.5 Lit.

Model Rule for permissible limit of heat (Permissible Heat Exposure Threshold Limit Values)Work & Rest Regiment Light Work Moderate Work Heavy WorkContinuous 30⁰ C 26.7⁰ C 25⁰ C75% Work + 25% rest in each hour 30.6⁰ C 28⁰ C 25.9 ⁰C50% Work + 50% rest in each hour 31.4⁰ C 29.4⁰ C 27.9 ⁰C25% Work + 75% rest in each hour 32.2⁰ C 31.1⁰ C 30⁰ C

Heat causes Marjolin’s ulcers on face due to sun burn or heat. It is pre cancerous condition. It also causes Keloid.

7/12/2012

2) NOISENational Programs on Occupational health are two:- 1) Hearing Conservation Programs 2) Vision Conversation ProgramDefinition :- According to ANSI (American National Standard Institute) any unwanted sound is Noise.Noise is conducted By 1) Air – Air Conduction (AC) and 2) Bone – Bony Conduction (BC)Sound Wave hits the tympanic Membrane, which then vibrates. In the middle ear there are three ossicles – Malleus, Incus and Stapes, situated between Tympanic Membrane & Round Window. The wave motion is converted into mechanical motion and passes through these ossicles passes to inner ear into perilymph. It vibrates the perilymph. In the inner ear are situated cochlear hair cells. Movements of their cilia produce action potential. The electric current passes through nerve cells to brain, where it is interpreted. Types of Noise:- a) Continuous

b) Impulse / Hammeringc) Interrupted:- i) Subjective ii) Objective

Units of Noise:- 1) Intensity or loudness dB measured by Noise Level Meter or Sound Level Meter2) Frequency or Sharpness Hz

dB has 3 scales A-Mimicking ear, B & CPermissible Limit as per Factory Act 1948

Hours of Exposure

dBModel Rule (India) As per OSHA Rule As per ACGIH

16 Hrs. - 85 808 Hrs. 90 90 856 Hrs. 92 90 -4 Hrs. 95 90 903 Hrs. 97 90 -2 Hrs. 100 90 951 Hr. 105 90 100½ Hr. 110 90 -¼ Hr. 115 90 -

1 dB :- When a dry leaf falls on earth, the colliding noise is 1 dB.Hammering or Impulse sound:-

Sound in dB No of impulses in 24 hours140 100135 315130 1,000125 3,160120 10,000

Deafness:- Types:-1) Conductive2) Perceptive or sensory neural3) Mixed

Audiometric ChartNormal Conductive Deafness (Bone Conduction)E-----E-----E----E-----E-----E-----E-----EO----O----O----O----O-----O----O----O (Air Conduction)

E-----E-----E----E-----E-----E-----E-----E (Bone Conduction)

O----O----O----O----O-----O----O----O (Air Conduction)

Both Abnormal ZonesPerceptive(Sensory Neural) Mixed

(Bone Conduction)E-----E-----E----E-----E-----E-----E-----EO----O----O----O----O-----O----O----O (Air Conduction)

E-----E-----E----E-----E-----E-----E-----E (Bone Conduction)

O----O----O----O----O-----O----O----O (Air Conduction)

Minimal Gap Long Gap

Audiometric Room:- Should be small and preferably AC. If it is AC room measure the noise in the room. It should be below 25 dB.Keep the frequency dB fixed and go on increasing the intensity Hz.Threshold of Perception = Minimal sound required to be audible to a particular person at that frequency.

In audiometry we measure AC & BC of each ear. We can measure Air Conduction upto 8,000 Hz and Bone Conduction upto 4,000 Hz. Normal AC & BC are upto 25dB. Bone Conduction is disturbed only when there is profound problem. AC & BC of each ear are denoted as follows:-AC Right ear :- 0----0----0-----0-----0 AC Left ear :- x----x----x-----x-----xBC Right ear :- E----E-----E-----E-----E BC Left ear :- ]----]-----]-----]-----]

First start from 100 dB then gradually go on reducing. Yes – No – Yes is the 50% response and that is the threshold. Destruction of hair cells of cochlea causes sensory neural deafness.Health Effects / Hazards:- 1) Auditory 2) Non auditoryAuditory:-Conductive as well as Perceptive 1) If it is a blast / loud hammering noise, the tympanic membrane may rupture causing Conductive deafness.

2) Occupational :- NITTS (Noise Induced Temporary Threshold Shift) or NIHL (Noise Induced Hearing Loss). NITTS is due to fatigue of Hair cells (Cochlear cells). In such case give complete rest for 48 hours and then do audiometry again, if still there is hearing loss then it is permanent hearing loss Characteristics if NIHS:- (Painless, Progressive, Permanent, Precedes NITTS, Preventable,

1) Gradual2) Painless3) Bilateral4) Irreversible5) Precedes NITTS6) In early stage normal conversation is not disturbed7) When exposure increases, invades upper & lower frequencies ranges8) Always starts at 4,000 Hz9) Sensory neural type of deafness10) Depends upon individual susceptibility11) Not amenable to treatment12) It can be measured

It starts at 4,000 hz

4,000 Hz

Why at 4,000 Hz ?Mechanical theory of Tanndof:- The initial segment (first turn) of cochlea is responsible for 4,000 Hz of frequency. The sound hit the first turn first where the first damage occurs.

Bone conduction:- We can measure bone conduction upto 4,000 Hz only.Recent concept of Fence Value:- High & Low fence valueHigh:- above 91.4 to 100% hearing lossLow:- upto 25% hearing loss

25 dB

How to calculate this fence value ?For example:-

--Hz Threshold of Perception--500 1000 2000 3000

Right Ear 40 35 40 45 =160/4=40Left Ear 50 45 50 35 =180/4=45

Now we calculate % hearing loss:- Lower level Upto 25 is normal, thusRight ear:- 40(value from above table) – 25 (normal) = 221dB loss = 1.5 % hearing lossSo% hearing loss in right ear =22 X 1.5 = 22.5 % hearing loss% hearing loss in Left ear from above table = 45 – 25 = 20 X 1.5 = 30 % hearing lossHow to calculate Hearing Handicapped ?Better ear = 22 X 5 = 110Poorer Ear = 30 X 1 = 30Combined together 110 + 30 = 140 /6= 23% handicappedBetter ear multiplied by 5 and Poorer ear is multiplied by 1This multiplication by 5 & 1 is a research work done by AAOO (American Agency of Ophthalmology and Otorhinolaryngeology).

Calculation of hearing impairment• From audiogram calculate the average of the thresholds of hearing for frequencies of

500,1000,2000,4000 and 6000 Hz.• Deduct 25 db.• Multiply it by 1.5• We will get the percentage of hearing impairment for that ear.

Percentage handicap• The percentage handicap of an individual is calculated using this formula :• [Better ear % x 5] + [worse ear % ]

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Old age Deafness is also Sensory Neural Deafness:- For compensation purpose age factor is not considered.For every of age after 40 yrs of age there is 0.5 dB of loss. So Age above 40 multiply by 0.5 dB for every year.

(pl. Check following equation)e.g age is 50 yrs. Age Factor - Industrial Factor50yrs. - 40yrs. = 10yrs. X 5 multiplication factor=50 - 5 (0.5dB X 10yrs.) =45%

Peculiarity of Noise:- NIHS is not detected in early stage without audiometry. At the range of 500 to 2,000 Hz normal conversation is heard. Thus in early stage hearing loss cannot be perceived by the patient. So signs & symptoms cannot be detected.

500Hz 2,000Hz 4,000 Hz

This range of normal conversation 500 to 2,000 is not disturbed, so normal conversation will not be disturbed. When the patient complaints shortness of hearing means it is advanced hearing loss.Personal Protective Equipment (PPE):-Ear Plug:- Maximum reduction possible is 15dBEar Muff: Maximum reduction possible is 20dBNow if first ear plug is worn and over that ear muff is worn, then ear plug reduction will be 5 and ear muff will be 15. This is only for air conduction and not for bone conduction. In that case Hearing Protective Helmet can be used, this reduces the exposure by 30dB

Property of Frequency:-1) Normal ear range is 20 to 20,000 Hz.2)It takes progressively less intensity to be audible, upto 4,000Hz.

25 dB

x120dB

x100dB

4,000 Hz3) From 1,000 to 4,000 Hz the response is fairly constant4) From 4,000 to 20,000 Hz a greater intensity is required for sound to be audible.5) Threshold of Pain:- at the intensity more than 140 dB we feel pain. So Threshold of pain is 140dB.Level of Intensity:- 1) Soft whispering Voice;- 30 dB

2) Soft Conversation:- 70dB3) Large chipping hammer:- 120dB4) Turbo Jet Engine :- 160dB

B) Non auditory Effects of Noise:- 1) Pupils dilates, Voluntary & Involuntary muscles contract. BP Increases, Blood Sugar increases – lasts for only few seconds2)Noise stimulates adrenal glands & induces catacholeaminesle& Circulatory disturbances.3) May cause nausea, Vertigo, increased heart rate, increased pulse rate.4) Causes more accidents more errors, less productivity5)Socially undesirable6) increased Physical & Psychological stress.7) Sickness & absentism8) Tendency to speak loudly9) Pulmonary functions decreases because of loss of surfactants. Thus increased infections.

How to differentiate old age deafness (Presbycusis) and Industrial noise induced deafness ?

1) Usually in old age dB loss is not beyond 65 to 75. In NIHL no age factor. 2) At age of 70 yrs. 5,000 Hz is mostly affected. 1,000 to 2,000 Hz does not become significant

until late in life. 3) 4,000 to 6,000 Hz affect is the early effect of age.

25dB

30dB 1KHZ

35dB 2KHZ

40dB 3KHZ

60dB 4KHZ

70dB 5KHZ

100dB Age 70 Yrs.

Here at the age of 70 years as the frequency increases more & more loss of hearing is seen.

Hearing Conversation Program:-

Aims:- 1) To prevent NIHL2) To reduce claim for compensation

It has 3 components:- 1) First Phase:- Physical Evaluation of Noise Exposure2) Medical evaluation of hearing3) Control of noise exposure. Noise slowing, mapping of area by SLM (? Sound Level Meter).It is a team approach. Leader of the team is Medical Officer.Function Members involvedIdentification of noise source Industrial Hygienist, Plant Supervisor, WorkersReduction of noise exposure level Plant Engineer, Industrial Hygienist, Audiologist,

Supervisors & WorkersHearing Measurements Ottologist, Aodiologist & Workers

Need Audiometers, Noise meters & Protective measures.Grades of hearing:-Grade Threshold of perception Hz.

500Hz 1,000Hz 2,000HzAbility to understand speech

Non Significant Below 25db No difficultySlight 25-40dB Difficulty with faint speechMild 40-55dB Frequent difficulty with friend’s speechModerate 55-70dB Frequent difficulty with loud speechSevere 70-90dB Can hear only shouted speechProfound 90dB + Very limited hearing

Fallacies of Personal Protective Equipment:-1) Gap between plug & Skin may be more

2) Quality is not upto the mark3) Material itself vibrates4) Bone Conduction cannot be obstructed

When two machines together are making noise

Difference between two machines Addition0 to2 3 will be added3 to 4 25 to9 1Above 9 0

e.g . Two machines of 85 dB are working at a time, then 85 + 3 = 88 is the cumulative effect.When to conduct audiometry test ?After completion of 8 hours of duty conduct first test. Here suppose you find threshold of perception is 40dB. Normal is 25 dB. Now here difference is 15. Give rest of 48 hours and then do audiometry again at the beginning f the shift. Now suppose you get threshold of perception 30 dB.Normal is 25. NITTS is 10 and NIPTS is 5. This loss of 5 will be permanent.

Treatment of NIHS:- Cochlear implantControl Measures:- - Engineering

- Administrative- Legislative

Sound absorbing material:- - Thermocoal, Wool, Glass wool, Anti eco panelsSLM:- Where person’s ear is getting contactEar plugs:- Rolled, Pulled, insertEar MuffsHelmets

250

500

750

1000

1500

2000

3000

4000

6000

8000-10

10

30

50

70

90

110

Frequency (Hz)H

earin

g (d

b)

25–40

40-55 dB

55-70 dB

70-90 dB

90 dB +

Management

• Medical treatment: • There is evidence that hearing loss can be minimized by taking mega

doses of Magnesium starting early after exposure to loud noise .• A Magnesium high diet also seems to be helpful as an NIHL preventive .• You can get magnesium from many foods. Foods rich in magnesium

include whole grains, nuts, and green vegetables. Green leafy vegetables are particularly good sources of magnesium.

• Rich sources of magnesium include tofu, legumes, whole grains, green leafy vegetables, wheat bran, Brazil nuts, soybean flour, almonds, cashews, blackstrap molasses, pumpkin and squash seeds, pine nuts, and black walnuts.

• Folate may prevent hearing loss in men Increased intakes of folate and folic acid may reduce the risk of hearing loss in men by 20 per cent.

• AdultAdolescent and adult males: 270 - 400 mg dailyAdolescent and adult females: 280 - 300 mg dailyPregnant females: 320 mg dailyBreastfeeding females: 340 - 335 mg daily

• Antioxidants such as vitamins C and E, and beta-carotene were not associated with any benefits.

OCCUPATIONAL DEAFNESSDefects in Audiogram

1/1/2013 3)VIBRATIONClassification of Vibration DisordersVascular ComponentStage

Grade Description

0 - No attacks1v Mild Occasional attacks affecting only tips of one or more fingers2v Moderate Occasional attacks affecting distal, middle phalanges (rarely proximal) of

one or more fingers3v Severe Frequent attacks affecting all phalanges of most of the fingers4v Very Severe As in stage III with tropic skin changes at finger tips

Sensorineural ComponentStage

Grade Description

0 SN Exposure to vibration but no symptoms1 SN Intermittent numbness with or without tingling2 SN Intermittent or persistent numbness with decreased sensory perception3 SN Decreased tactile discrimination or loss of manipulative dexterity

Preventive measures of vibration disorders1) Training of potential hazards of vibrations.2) Need to service their tools regularly.3) To grip the tools as per rules. Non slippy, light grip4) Use of PPE like Attenuated Gloves (antivibration gloves). Due to these gloves there will be no injury, hands will remain warm & vibrations are reduced.

Raynaud’s Phenominon:-To develop Raynaud’s Phenomenon 3 factors are responsible:- 1) Cold Weather 2) Vibration & 3) SmokingCold weather factor :- Previously this was considered as disease of cold countries. Now-a-days it was found in our country also.Mechanism:- 1) Stimulation of sympathetic nervous system with circulatory disturbances

2) Thickening of medial coat of digital artery ( Muscle hypertrophy), thereby occluding the lumen3) In later stages results in cyanosis (Acrocynosis)4) Finally tropic changes to the finger tips.

Smoking & Occupational Diseases:-Chronic cough, Chronic Bronchitis, COPD, CO toxicity, Cyanide Toxicity, Lead, Cadmium, Benzene ToxicitySynergistic effect:- Lung Carcinoma in Asbestosis, VigenosisAsbestosis, Bysinosis Synergistic Effect of Ca lung

Raynaud’s Phenomenon:- Precursor of Cancer:- Leuplekia, Lung cancer itself, High B.P., Atheroma:- Nicotine, CO causes atherosclerosis, Foetal Development Abnormalities, Foetal Toxicity, Abortions Kidney Damage.

Prevention:- Teach Skills, Attenuated Gloves (Keeps hands worm & moist, prevent injuries, reduces vibrations)Periodic Medical surveillanceSource of vibration

Reduce transmission of vibrationRubber padding, rubber matting over vibrating platformReduce ExposureAdministrative measuresWhole body vibration (WBV):- 0.1 to 20 Hz frequency can cause WBVAffects eyes, vestibular apparatus (Motion sickness 0,1 to 0,63 Hz), adrenal cortex, thyroidHand Arm Vibration Syndrome (HAVS):- 50 to 300 HzVascular;- blanching, , cyanosis, trophic changes Sensorineural:- numbness, tinglingMusculosketal:- Carpo-metacarpal pain, arthritis, wrist pain, arthralgia,

4) COLDSubnormal atmospheric temperature. 1) Generalized effects 2) Local Effects

Generalized effects:- i) Coldness 2) Shivering 3) Weakness 4) Desire to sleep 5) Coma 6) DeathLocal Effects:- Depends upon Freezing Temperature of Non Freezing TemperatureFreezing Temperature:- 1) Frost Nip

2) Frost Bite

Superficial Deep Fluids from fingers solidifies & thenSuperficial Deeper tissues involved Again when temp, of atmosphere skin is involved causes gangrene Increases it liquefies – seen in cold Usually no gangrene storage workers.

Freeze Thaw refreeze causes tissue injury treatment of choice is amputation

While working worker gets sudden death due to release of K from the cells.

NFT( Trench Foot, immersion foot, Flender’s foot, Shelter’s limb):- Occurs by standing in cold water:-Preventive Measures:-

Room “B” :-

Temp. is subnormal

Anti Room “C”

Temp = A+B 2

Room “A”

Normal Temp.

Take ½ hour rest in the Anti room before the duty and ½ hr rest after the duty.

5) IONIZING RADIATION

The radiation which can penetrate the tissue & deposits it’s energy within is called as ionizing radiation.Examples are Alapha, Beta, Gamma rays, cosmic rays, X-Ray

Hazards

Immediate DelayedBurnsIonising Sickness / Syndrome Somatic GeneticNausea, vomiting 1) Carcinogenic 1) Chromosomal Mutation e.g Sterility

2) Leukaemia 2) Point Mutation:- here gene is 3) Foetal developmental involved. Abnormalities4) Shortening of life expectancy

Most dangerous ionizing radiation is Alpha α though it’s penetration power is less…… How & Why ?

H = DQH = Dose equivalent measured in Sievert D = Absorbed dose Q= Quality factorQuality factor in case of Alpha α is 20. For X-Ray it is 1

Penetration PowerRadiation Penetration ability

Air Tissues LeadAlpha α 4 cms. 0.05 mm 0Beta β 6 to 300 cms 0.06 to 4 mm 0.005 to 0.3 mm

Gamma ϒ 400 meters 50 cms. 40 mmX-Ray 120 to 240 meters 15 to 30 cms 0.3 mm

Electromagnetic :- X-Ray & Gammaϒ Corpuscular:- Alpha α & Beta β

Units of IR H is measured in sievert. 1 Sievert = 100 RemD (Dose) is measured in Greys. 1Rad = 0.01 Grey.

Permissible Exposure Limits:-Radiation should not exceed to 5 Rad in a year (Old concept).Newer:- ICRP (international Commission on Radiological Protection):- 235 Rems of whole body radiation for a person occupationally exposed from 18 to 65 years of age

Units of Radiation:-A – Activity of a radioactive material is number of nuclear disintegration per unit of time. It is

measured in Bq (Becquerel). 1 Bq = 1 disintegration / secondFormarly it was also known as Ci (Curie)

B- Potency of radiation is measured by a) Roentgen:- Unit of Exposure (Old)Newer International System unit is C/Kg ( C is Coulomb)

1 R = 2.58 X 10⁻⁴ CKg⁻¹ = 1 RotgenRad is replaced by Gray:- 1 Rad =0.01Gy Absorbed Dose:- old is Rem which is replaced by Sievert 1Sievert = 100 RemOnly in case of X-ray Rem = Rad

6) NON IONISING RADIATIONThey cannot penetrate tissues. Their wave lengths are characteristics. So classified according to their wave lengths.UV VIBGYOR IR 1 nm = 10⁻⁹meterUV = 100nm (nano meter) to 400 nm 1 ᵤm = 10⁻⁶

Effects of Ionizing Radiation depends Upon:- 1) Type of Ionizing Radiation 2) Quality of IR 3) Dose of IR 4) Dose Rate of IR 5) Tissue Distribution of IR Dose related Effects:- A uniform Whole Body Irrediation with 1 to 10 Gy. It is also known as Low Linear Energy causes:- 1) Pancytopenia leading to Infections & Bleeding usually 2-4 weeks after

Exposure2) In Human Bone Marrow the total no of Nucleated Cells are reduced at Day 1 of exposure by a) 10-20% Reduction after 1-2Gy Exposure

b) 25-30% Reduction after 3-4Gy Exposurec) 50-60% Reduction after 5-7Gy Exposured) 80-85% Reduction after 8-10Gy Exposure

Types of Leukemias found :- 1) Acute Myloid Leukemia 2) Acute Lymphoblastic Leukemia

Visible light = 400nm to 760 nm 1 mm = 10⁻ᶟInfra Red = 760 nm to 1 mmMicro wave = 1 mm to 1 meter

The effects are mainly on skin & eyes. 1) Cornea:- Less than 300nm can be absorbed2) Lens:- 300 to 400 nm can penetrate and reach inside3) Retina:- More than 400 nm can reach upto retina

UV Rays:- 3 types UV(C) = 100 to 280 nmUV(B) = 280 to 315 nmUV(A) = 315 to 400 nm

UV(C) can be absorbed in upper atmosphere.UV(B):- Sources- Welding, solar

Acute effects:- Arc EyeChronic effects:- Sources:- Snowy region (High Altitude), Welders

Effects:- 1) Chronic Blephro conjunctivitis with loss of elasticity of conjunctiva2) Band degeneration of cornea

UV(A):- Mainly absorbed in lens, little can reach upto retinaEffects:- Acute:- Eye:- 1) Induces cataract formation

2) Severe conjunctival & Corneal lesions e.g. Ptyrigium, Recurrent corneal lesions

Skin:- Tanning without superficial burning of skin.Chronic:- Eyes:- Increased concentration of chromatophores in the lens. Thus yellowish

discolouration of lens. In later stage it will protect the eye from UV(A)

Infra Red:- Blue colour to some extent deposits it’s energy into eye.

So long term exposure to blue light is to be avoidedIR(A) – 1.4 ᵤmIR(B):- 1.4 ᵤm to 3 ᵤmIR(C):- 3 ᵤm to 1 mm. When glass is melted IR & Radiation will affect the eye.IR(A):- Usually not visible to the eye but we can see a red glow.

Sources:- 1) Molten glass or metals at temp, above 1,500⁰C 2) Funnaces 3) Heating & Dryibg appliances 4) Sun Rays

Effects:- It affects lens, retina & choroid lining, leading to retinal oedema Pigmentation of retina Cataract formation due to protein denaturisation.

Diagnosis:- Not by ophthalmoscope. Need Fluorescent Angiography IR (B) & (C):- Source:- Sunrays, Furnaces, laser

Effect:- Cataract formation. Protein degeneration mainly occurs in glass.

Microwave:- Sources:- Radar, Ovens, Satellite communication towers, Insect control, Surgical DiathermyEffects:- Cataract formation

Laser:- (Light Amplification of Stimulated Emission R........)Types:- 1) Columnated:- Parallel light rays

2) Monochromatic:- Only one wavelength3) Coherent:- Phase wise

Also 1) Continuous wave2) Pulsed:- a) Continuous b) Short Duration:- Q switched

Sources:-1) Engineering Process:- Drilling, cutting, welding2)Holography3) Communication4) Civil engineering measurement5) Medical application;- A) Ophthalmologyi) for diagnosis:- i)to detect opaque ocular media like

cataract, vitreous haemorrhage.ii) Scanning Laser Ophthalmoscopy for images of retina

For Treatment:- of Glaucoma, Diabetic retinopathyB) Dermatology;-1) To produce burn in dermatitis

2) To burn benign vascular tumours 3) To improve cosmetic appearance.

Hazards of Laser:- Retinal burn, Skin Burn, Fire hazardsLaser safety as per British Standard no. 4083 (1983)

Class I :- no hazardClass II:- Not hazardous within a blink reflexClass III:- Viewing directly is hazardousClass IV:- High Risk Laser – skin & fire hazard

7) BAROMETRIC PRESSURE

It is pressure of atmosphere at sea level. Normal atmospheric pressure at sea level is 100KPa.High Baro-pressure:- When barometric pressure is more than 7,000KPa barometric pressure effect will start. The effect also depends upon the media – e.g. Air at the bottom of mines; Water- e.g. divers. The depth increases pressure.

High Barometric Pressure Effects

Compression Barotrauma Decompression illness (Cassion’s Disease)

Compression Barotrauma:- 1) Middle ear barotraumas:- Characterised by pain in affected ear radiated down to the neck.2) Sudden relief of this pain may be due to rupture of tympanic membrane. This rupture will be towards the middle ear, as the pressure is from outer ear side.If the ear muffs are used then the rupture will be towards outer ear, due to the pressure transferred from eustachian tube to the middle ear.3) Alternobaric Vertigo:- Due to inequality in pressure between right & left middle ear, which is transient.4) Inner ear barotrauma:- This is due to transmission of increased CSF pressure through perilymph. This may cause rupture of oval or round windows, and fistula formation, leading to persistent vertigo, & total or partial sensoryneural hearing loss. Treatment of choice in this case is immediate operative repair.5) Sinus, eyes & teeth:- Pain in sinuses, conjunctival oedema or haemorrhage, teeth ache6) Ear & Skin infections mainly due to Pseudomonous species.

Decompression Illness:- Any return from raised to normal atmosphere pressure may be associated with some clinical manifestations. Some of them can be serious. There are two clinical types:- 1) Expansion of gas & 2) Evolution of bubbles in the body mainly due to Nitrogen gas, and also to some extent Helium.Microbubbles are formed due to high pressure below. If ascent is slow they are eliminated by exhalation. If the decent is rapid then these gases are retained in tissues & organs, which can be potentially fetal.

Health Hazards:- 1) Cutaneous decompression illness (Skin Bends):- i) Itching of skin around ears, face, neck, arms & upper trunk, due to cutaneous absorption of nitrogen.ii) A blotchy red or purple rash, mainly over upper trunk, may be due to superficial vasodilatation & stasis called as Cutis Marmorata.iii) Pu De Orange usually seen in limbs, as well as oedema of face & trunk due to lymphatic blockage by bubbles. Scar like depressions are formed on the skin.iv) Sensation of insects crauling on the skin.

2) Musculoskeletal pain. Bends (Bubbles within the joints, mainly affect shoulder. It is called as bends because pain is relieved on bending the joint) :- Pain in knees, shoulders & other synovial joints characterized by redness, oedema & limitation of movements.3) Constitutional manifestations:- Malaise, anorexia, fatigue etc.4) Cardiopulmonary decompression illness:- 5) Pulmonary Barotrauma:- Chest pain, crepetitions in suprascapular region, Pneumothorax causing breathlessness. Chokes (Substernal pain, cough & Dyspnoea, pain increasing on breathing) due to build of venous gas emboli, passing to

the lungs through Pulmonary artery. The gas bubbles accumulates in Pulmonary capillaries. & associated vasoactive products of surface activity in the pulmonary circulation.

6) Neurological Decompression illness:- i) Loss of consciousness due to gas emboliii) Hemi, mono, paraplegiaiii) Vertigoiv)Spiciness:- detachment from realityv)visual disturbancesvi) Behavioural changesvii) Psychosisviii) Da Staggers:- Associated with nausea, vomiting, &/or ipsilateral deafnessix) Onset of tingling or wooliness in the feet.x) Diminished sense of vibration (imp)xi) Impairment of sphincteric tone--> Retension of urinexii)Urinary & fecal incontinence.

7) latency:- Loss of consciousness on arriving the surface due to relative rapid assent. Characterised by the conditions associated with arterial gas emboli.

Long Term Effects:- 1)Hearing loss2) Pulmonary Changes:- i) Occupational narrowing of small airways leading to

20% reduction of FVCii) Diminished gas transfer capacity

3) Neurological:- CNS changes4) Dysbaric Osteonecrosis:- Severe joint pain (imp)

Treatment:- 1) End the drive2) If conscious & co-operative – lay on the back and give O23) If not responsive but breathing, then lay on the side, head supported and O24) If not breathing then CPR, treatment of shock5) Serious cases:- transfer to recompression chamber by low altitude flight & give hyperbaric O2

Prevention:- 1) Deep dives then shallow2) Asent rate not more than 18 meters or 60Ft. Per minute. Five minute os safety shock while coming up. Interval between two dives 16hours. 24 hrs before or after dive refrain from flying.

Low Barometric PressureEffects are acute & chronicAcute:- Found in Jet pilots, person staying at high altitude, mountaineers

1) High altitude Pulmonary Oedema, characterised by progressive dyspnoea, tachypnoea, cyanosis. Treatment is immediate descent & oxygen inhalation2) High altitude Pulmonary Oedema:- Slurred speech, frontal headache with neck stiffness, temporary loss of peripheral vision, impaired co-ordination & ataxic gait.Treatment is immediate descent & oxygen inhalation3) Acute Mountain Sickness:- Headache, nausea, lethargy, impaired memory. Treatment is acetazolmide prior to assent.4) Migraine Headache:- Nausea, numbness & loss of peripheral vision but no headache. Treatment is immediate descent & antiemetics.5) Bronchopneumonia6) Perforation of ear drum from inside.

Chronic:-1) Bronchial Asthma2) Mitral valve prolapsed3) Paroxysmal Supraventricular Tachycardia 4) Paroxysmal Atrial Tachycardia 5) Essential Hypertension6) High Altitude Haemoglobinopathy (imp)7) Risk of spleenic & Renal Infarction.8) Insomnia

8) ELECTRO MAGNETIC FIELD (EMF)In India electricity is on 50 cycles/sec, in US it is 60 cycles/sec. It should be as minimum as possible.Very very low intensity of EMF unit is Tesla.Exposure sites;- very low:-TV, Computers, Cell Phones,

People living below high tension wires, Cell Phone Towers, RadarsAs per ACGAH maximum permissible level is 1 mTEffects:- 1) Health:- 1) Carcinogenic:- Mainly reproductive organs are affected

2) Effective on Reproductive System:- If Male :- 1) his offsprings suffer from brain tumour

2)Foetal developmental abnormalitiesFemales:-Her offsprings suffer from 1)foetal developmental

Abnormalities2) Miscarriages, abortions

3) CNS:- Psychosis, suicidal tendency e.g. military person working in Radar4) Effects on pace maker but no effect on CVS

9) ELECTRICITYSeverity of Electric Current depends upon 1) Type & Voltage of electric current

2) Duration of the flow within the body 3) Resistance at the point of entry4) Path through which it is passing into the body

Most dangerous is AC. AC flow of 60 cycles/sec will produce tingling sensations (tingling is a threshold of perception) at 1-2 mA. While if it is DC it need 5 mA current to produce tingling sensation.Health Effects;- 1) Immediate life threatening effect is Cardiac or Respiratory Arrest, requires

immediate CPR2) Electrical burns:- Burn at the point of entry of the current & at exit and in between.

So we cannot measure the degree of burns in this case.3) AC of 60 Hz at 110 to 220 V travelling across the chest for less than 1 second is capable of inducing ventricular fibrillation at current as low as 60 to 80 mA.4) Electrical current can burn the tissue at the point of entry as well at exit & in between. Thus there is more tissue damage than it is apparent.5) Current flows along the path of blood vessels & muscles may cause thrombosis & necrosis of the tissues at sites remote from apparent injuries.6) There may be severe muscle contractions leading to fractures of bones.7) Oliguria due to destruction of muscles & production of myoglobin in the kidneys.

Treatment:- First Aid & Hospitalization

10) LIGHTLight

Dimness Brightness

Illumination is measured by Lux Meter.Dimness:- Dim Light:- Chronic effects are mainly seen in miners working in dim light for so many years, leads to Miner’s Nystagmus.Brightness:- Effects are Acute & Chronic. Glare Index is 12

Acute:- 1) Glare;- Search light directly falling on the eyes. Also reflected light. At high altitude falling sunrays on snow causes reflection.Symptoms:- Watering, lacrimation, Pain, Redness in eyes, foreign body sensation,

DiplopeaChronic:- Fatigue of eye muscles, annoyance, watering

Acute & chronic both effects are reversible.

11) ULTRASOUND

Very safe. If person is working for very long time USG disintegrates the cellular structure. The target is RBCs, causing anaemia.

12) MOISTURE

65% humidity is pleasant. Increase or decrease in humidity is not desirable. If steam is generated, it causes lung disorders. Dryness is also not desirable.

13) COLOUR

Red & White stimulates. In industries several colours are used to 1) Improve their Quality of workmanship 2) To reduce no of rejections 3) To reduce accidents 4) To reduce absenteeism 5) To raise house keeping 6) To improve moral of workers.Adverse effects of colour are mainly due it’s psychological effects.

Colour Psychological EffectsRed & White StimulatingYellow FresheningOrange Tension producingLight Green & Blue Relaxed feelingPurple Depressing

Apparent size of the object:- In green & blue coloured machines the surface recedes, so they look smaller. Red & Yellow:- Objects come forward

Temperature feeling:- Red & Yellow:- warm feelingBlue & green;- Cool Feeling