Occupational Hazard ``Source or situation with a potential for harm in terms of injury or ill health, damage to property, damage to the workplace environment, or a combination of these``

Occupational Health Hazards Types » Physical » Chemical » Biological » Mechanical » Psychosocial

Diseases due to Physical Agents Heat – Exhaustion, Syncope, Cramps, burns, Prickly Cold – Frost bite Light – Occupational Cataract, Illumination Atmospheric-pressure – Caisson disease, explosion Noise – Occupational deafness Radiation – Cancer, Leukemia, aplastic anemia Electricity – Burns, Shocks

Heat Illness Predisposing Factors – Physical activity – Extremes of age, poor physical condition, fatigue – Excessive clothing – Dehydration – Cardiovascular disease – Skin disorders – Obesity – Drugs Phenothiazines, Anticholinergics, Diuretics, Amphetamines, Cocaine, MAOIs

Chemical Hazards Routes of entry – Inhalation (main route of entry), Ingestion, skin absorption Chemical agents: – Metals - Lead, As, Hg, Cd, Ni, Co – Aromatic Hydrocarbons - Benzene, Toluene, Phenol – Aliphatic Hydrocarbons - Methyl alcohol – Gases - Simple asphyxiants : N 2, CH 4, CO 2 Chemical asphyxiants : CO, H 2 S, HCN Irritant gases : Ammonia, SO 2, Cl 2

TLV (Threshold Limit Value) “Time-weighted average concentration for a normal 8-hour working day and a 40-hour working week, to which nearly all workers may be repeatedly exposed day after day, without adverse effect”

Biological Hazards Bacteria – Tetanus, Tuberculosis, Anthrax, Brucellosis (Milkmen), Gonorrhea Virus – Hepatitis, HIV Protozoal & Parasitic – Malaria, Hookworms, Hydatid (Dog-handlers), tapeworms Fungi (Agri-workers) – Tinea-infections, Psittacosis, Coccidiomycosis, Ornithosis

Mechanical Hazards Injuries – Falls, cuts, abrasions, concussions, contusions Ergonomic Disorders – Musculo-skeletal disorders(MSDs), Cumulative-trauma-Disorders (CTDs) Ergonomics – Adjustment of Man & Machine Ergo-friendly tools – Tools which reduce the stresses or problems resulting in CTD’s / MSD’s.)

Psychosocial Hazards Lack of job satisfaction, insecurity, poor interpersonal relations, work pressure, ambiguity Psychological & behavioral changes – hostility, aggressiveness, anxiety, depression, alcoholism, drug addiction, sickness absenteeism Psychosomatic disorders – Hypertension, headache, body-ache, peptic ulcers, asthma, diabetes, heart disorders

Occupational Lung Diseases (Pneumoconiosis) Pneumoconiosis is a group of lung diseases which result from inhalation of dust in certain occupations. Let’s consider a coal mine which contains approximately particles/ml, will inhale between 100 to 150 grams of dust yearly. Of the dust inhaled, about 1 to 10 grams is deposited in the alveoli, but only about 0.5 g is permanently retained. After 40 years of working, this amounts to 20 grams, half as much as the weight of the normal dried lung.

Classification of Pneumoconiosis Benign Pneumoconiosis Simple Pneumoconiosis Complicated Pneumoconiosis

Benign Pneumoconiosis Dust could not Produce fibrosis Examples include: – Baritosis: pure Barium sulphate and oxide – Siderosis: ferric oxide – Titanosis: titanium oxide – Chalkosis: calcium salts

Simple Pneumoconiosis Inhaled dust causes only minimal fibrosis Examples: – Silicatosis: inhalation of complex silicates (not free silica) e.g., clays – Vegetable dust pneumoconiosis: Mill fever: organic dust Byssinosis: cotton dust Farmer’s lung: grain dust Bagassosis: sugar-cane fibres

Complicated Pneumoconiosis Produce Progressive Massive Fibrosis Examples: – Silicosis: inhalation of free crystalline Silica SiO2 – Asbestosis: inhalation of fibrous tri-magnesium silicates – Talcosis: inhalation of talc powder – Coal miner’s pneumoconiosis: inhalation of coal dust

Nature and chemical composition Size of dust particles Concentration of dust in atmosphere Duration of exposure Individual susceptibility Factors affecting the development of disease (by depositing dust particles in the resp system)

Nature and Chemical Composition Inorganic dusts e.g. Silica, Asbestos Massive progressive fibrous reaction in the lung Organic dusts e.g. Cotton dust, grain dust, sugar-cane fiber Asthma bronchitis, non distinguishable

Size of Dust Particles 10-5 μ: Removed from upper respiratory tract 5-3 μ :Deposited in the mid respiratory tract 3-1 μ:Deposited directly in the alveoli < 1 µ: Move in and out of the alveoli with air, – may be deposited in alveolar wall by impaction, or being caught by alveolar movement

Size of Dust μ Upper Respiratory tract μ Mid respiratory tract μ Alveoli

Study of some common Pneumoconiosis Silicosis Pathological condition of the lung due to inhalation of particulate matter containing free silica or uncombined silica (SiO 2 )

Permanent scarring of the lungs caused by inhaling silica (quartz, SiO 2 ) dust Slowly progressive, nodular, fibrosing pneumoconiosis Thickened pleura Fibrosis 03/09/201521

Common Occupations with Exposure to Silica Mines Porcelain Sand bricks industry Glass industry Gun industry Grinding of metals using sand stone

Pathology Fibrotic nodules develop by a particular process in which fibrous tissue is laid down in concentric rings around a central core of silica particles as an onion

Manifestations Symptoms shortness of breath while exercising fever occasional bluish skin at ear lobes or lips fatigue loss of appetite

3 Types of Silicosis (based on amount of exposure and length of time) Chronic occurs after 10 or more years of mild overexposure to silica the most common of all types may go undetected for years Accelerated develops between 5 and 10 years of moderate overexposure Acute develops within weeks up to five years due to breathing very large amounts of silica

Diffuse fibrosis of the lung parenchyma Asbestos fibers, highly resistant to heat, acids and chemicals Widely used in industries Banned from use globally since 1973 because it is highly carcinogenic 03/09/201526

Asbestosis Parenchymal lung fibrosis with or without pleural involvement due to inhalation of asbestos fibres. bronchogenic carcinomamesothelioma More dangerous than silicosis as it predisposes to bronchogenic carcinoma and mesothelioma of the pleura and peritoneum

Complications Bronchogenic carcinoma Mesothelioma

Prevention of Pneumoconiosis

Medical measures Pre-employment examination Periodic examination Conducted every year Include LFT If susceptible worker (significant effect across shift after few month of exposure) should be transferred to other job Health education Nutrition Prohibition of smoking

Engineering Controls Designing-building, Work station Good Housekeeping, wet mopping Ventilation Mechanization, Vacuum cleaning Substitution Enclosure machine dust Isolation/Segregation Local Exhaust Ventilation Personal Protective Devices Work Environment Monitoring Statistical Monitoring