This document discusses health problems in important occupations, focusing on health hazards in foundry work. It notes that foundry work involves risks from physical hazards like heat, noise, vibration and radiation as well as chemical hazards like dusts, fumes, and gases. Common health issues for foundry workers include silicosis from sand dust, dermatitis from chemicals, metal fume fever, noise-induced hearing loss, heat illness, and injuries from accidents. The document recommends engineering controls, personal protective equipment, health monitoring, training and other measures to prevent occupational health issues for foundry workers.

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2. Section 11 : Occupational Health
223 Introduction & General Concepts L S. Vaz, A K Jindal, Puja Dudeja 1270
224 Health Problems in Important Occupations Ashok K. Jindal, Puja Dudeja 1271
Leo S Vaz, Ashok K.
225 Organ / System Diseases Peculiar to Occupational Settings 1274
Jindal, Puja Dudeja
Ashok K. Jindal, Leo S.
226 Industrial Accidents 1279
Vaz, Puja Dudeja
227 Industrial Toxicology Ashok K. Jindal, Puja Dudeja 1281
228 General Measures of Prevention & Control of Occupational Diseases Ashok K. Jindal, Puja Dudeja 1286
229 Ergonomics Leo S Vaz 1288
230 Physical Working Environment Leo S Vaz, Ashok K. Jindal 1290
231 Social Security and Labour Laws Ashok K. Jindal, Puja Dudeja 1295
232 Medical Evaluation of Workers Leo S Vaz 1298
National Programme for Control and Leo S Vaz, Ashok K.
233 1300
Treatment of Occupational Diseases Jindal, Puja Dudeja

3. the physical hazards and their adverse health effects due to
223 Introduction & General Concepts them.
Chemical Hazards : Almost all the occupations in industry
Leo S. Vaz, Ashok K. Jindal, Puja Dudeja have scope of exposure to some chemical substance or the other.
These substances may be solids, liquids or gases, vapours,
fumes, dusts, smoke, mist, fog or smogs.
Definition
Biological Hazards : Viruses, rickettsiae, bacteria, fungi,
‘Occupational health should aim at the promotion and
protozoa and helminthes may be transmitted in certain
maintenance of the highest degree of physical, mental and
occupations.
social well being of workers in all occupations; the prevention
amongst workers of departures from health caused by Mechanical Hazards : Mechanical factors of importance in
their working conditions; the protection of workers in their illness and injury in industry are defective design of machinery,
employment from risks resulting from factors adverse to health; defective procedures, unguarded machinery, protruding and
placing and maintenance of the worker in an occupational moving parts, falling heavy objects and poor ergonomics.
environment adapted to his physiological and psychological Psychosocial Hazards : Factors responsible for psychosocial
equipment and to summarize : the adaptation of work to man illness are frustration due to type of work, risks involved in
and of each man to his job’. work, monotony, long working hours, lack of recognition, lack
- Joint Committee of WHO and ILO, 1950 of job satisfaction, poor remuneration, poor man management,
lack of welfare activities and tensions at home and place of
Health Hazards in Industry work. The indicators for psychosocial group of are chronic
Hazards in the industry can be due to physical, chemical, absenteeism, mass leave lock outs, strikes and unexplained
biological, mechanical and psychosocial causes. Table - 1 gives reduction in production.
Table - 1 : Physical Hazards in an industry
Hazard Occupation Health Effects
Foundry, glass, heavy metal industries, Heat stroke, heat hyperpyrexia, heat exhaustion, heat
Heat underground mines, vulcanization of rubber, syncope, heat cramps
spinning room of textile industry
Armed forces, food processing and preservation
Cold Chill blains, frost bite, trench foot, erythrocyanosis
industry
Light Mines, driving Eye strain, eye fatigue, nystagmus, headache
Auditory : Auditory fatigue, permanent hearing loss;
Noise Machinery in factories producing loud noise Non auditory : Nervousness, fatigue, decreased efficacy,
annoyance, raised blood pressure, loss of sleep
Vibration induced white fingers due to Raynaud’s
Vibration Pneumatic drill users
phenomenon, osteoarthritis of wrists, elbows, shoulders.
UV radiation Arc welding Glare and dazzle, pain and gritty feeling in the eyes
Radiography, radioisotope use, processing
Ionizing of plastics, food preservation, industrial
Cancer, leukemia, aplastic anemia, pancytopenia
radiation radiography, industrial hydrology, chemical
industry and medical research
• 1270 •

4. pattern making can release products which may cause asthma
Health Problems in Important
224 Occupations
in exposed workers. Vapours from various resins can initiate
severe allergic reactions. Carbon monoxide gas is produced
in substantial amounts by a variety of furnaces. Exposure
Ashok K. Jindal & Puja Dudeja to concentrations of 500 to 1000 ppm for approximately 30
minutes may precipitate headache, accelerated breathing,
nausea, dizziness and mental confusion. Thus a possible
Health Hazards in Foundry Work secondary effect of exposure is an increased risk of accident
Founding consists of pouring molten metal into a mould which and injury to the worker. Various metal fumes may be generated
is made to the outside shape of a pattern of the article required during founding processes, especially during melting and
and contains, in some case a core which will determine the pouring operations. Lead, magnesium, zinc, copper, aluminum,
dimensions of any internal cavity. The basic principles of cadmium, antimony, tin and beryllium fumes are commonly
foundry work have hardly changed over the years though a lot present in non - ferrous foundries. Iron oxide is the major fume
of modernization has come, making plants more mechanized generated in iron and steel operations. ‘Metal fume fever’ may
and automatic. Molten metal is introduced into the mould. result from exposure to these contaminants. This is an acute
After cooling occurs, the mould is subjected to a ‘shakeout’ illness of short duration which commences some hours after
procedure, which releases the casting and removes the core. inhalation of the metallic fumes. The initial symptoms are flu -
The casting is then cleaned and any extraneous metal is like; nausea, headache, dry throat and coughing, and muscular
removed from it. pains, chills and sweating may occur later. Recovery is usual
within 24 hours after removal from exposure. The lead hazard
Process
in furnace cleaning, dross disposal and the fettling of lead
The various processes involved in foundries include Moulding alloys deserves particular attention. Besides dusts & fumes in
& pattern making, Core making, Melting & pouring, Shakeout foundries are known to have carcinogenic properties.
(Knockout) and Dressing & cleaning.
Occupational Dermatitis : Formaldehyde, isocyanates, various
The various process outlined in the preceding section give rise resin products associated with pattern making and core making
to heat, molten metal splashes, dusts, noise, gases and vapours processes can irritate the skin and may precipitate allergic skin
in the foundry environment. If these hazards are not controlled reactions.
or contained, serious health effects in exposed workers can
Noise Induced Hearing Loss and Related Effects : The foundry
result. Foundry work also involves various manual operations
process generates noise from various sources, including scrap
which carry a risk of physical injury. The occupational health
handling, furnace charging and EAF melting, fuel burners,
and safety issues are encountered during foundry activities
shakeout and mould / core shooting, and transportation and
include Physical hazards, Radiation hazards, Respiratory
ventilation systems. Some fettling workers have been shown
hazards, Electrical hazards, Noise exposure, Burial hazards,
to be exposed to levels of noise over 100 db; shakeout and
and Fire & explosions. The common and important ones are
knockout processes are typically associated with readings of
as follows :
90 - 110 db. Mechanical sand mixing processes and forced
Silicosis : Silica dust presents a prominent hazard of silicosis. draught furnaces may produce noise levels of 90 - 100 db.
This dust is generated during mixing, moulding, shakeout and Extraction fans, die - casting machines, core - making and shell
dressing operations, and during sand conditioning for re - use. - making equipment may also be sources of excessive noise.
The dust arises from quartz in the sand, and the concentration
Vibration : Pneumatic grinding and chipping tools used in
of free silica in the air varies with the handling process, the
dressing the cooled castings may cause vibration induced
efficiency of dust control, the chemical composition of the sand
health effects in operators. Hazardous vibration equipment
and the physical state of the sand, that is, whether the sand is
may also be utilized in shakeout and core removal operations.
screened or un-screened, wet or dry and is either dumped or re-
milled, with water and binder added before it is re - used. The Heat and Heat Stress : Radiant heat is the major contributor
amount of respirable dust is increased by such re - use. Sand to the heat load imposed on the worker by the environment.
is dry at the mixing or ‘mulling stage prior to mould making’, Convective heat transfer adds to this radiant heat. Protective
and at the shakeout stage; this dry sand is potentially more clothing is worn for protection against the heat radiating from
hazardous than wet sand. Screened sand does not produce as the heat sources and against contact with molten metals.
much silica dust as unscreened sand and pure quartz sand is Such clothing greatly restricts the potential for body heat
more hazardous than olivine sand. Abrasive blasting processes loss via evaporation. The effects of heat range from decreased
may involve the use of sand containing high concentrations of concentration to painful cramps, fainting, heat exhaustion
free silica. and heatstroke. Heat stress can also aggravate the effects of
exposure to other agents such as noise and carbon monoxide.
Irritation, Allergy, Asthma, Metal Fume Fever, Malignancy:
In addition to dusts, the air in foundries may contain the Accidents & Injuries : Serious burns may result from splashes
potential irritants like formaldehyde, various amines and of molten metal in the melting land pouring areas of foundries.
phenol. These contaminants are generated primarily by Frequent, unprotected viewing of white - hot metals in furnaces
the core making and moulding processes, and may irritate and pouring areas may cause eye cataracts. Eye injures from
the eyes and the respiratory tract. Some hardwoods used in molten metal or fragments of metal may occur in pouring and
• 1271 •

5. dressing areas, during continuous casting processes, non - recovering from a fever, and any dehydrated worker must be
ferrous molten metals, such as copper and aluminum, may regarded as being in a high - risk category for heat illness.
explode violently if they contact water. Injuries related to the Unacclimatised persons must be given time to acclimatize to
manual handling of materials, and injuries due to falls, may work in the heat. Planned job rotation can assist in reducing
occur. Grinding wheels used for dressing small articles may exposure to heat. Cool water should always be available in
result in hand injuries. close proximity to hot working areas and encouragement be
Preventive Measures given for the use of these facilities. The exposure of workers
to radiant heat can be reduced by the strategic positioning of
Monitoring & Evaluation of Exposure : Monitoring of shields between workstations and heat sources. Clothing should
the work environment, personal monitoring and biological be carefully selected so that a balance between protection and
monitoring should be undertaken, In some cases, biological facilitation of heat loss through evaporation is achieved.
monitoring may be required to supplement static or personal
monitoring. When developing a monitoring programme in Personal Protective Equipment : Personal protective equipment
foundries, due consideration should be given to the hazards such as goggles, padded gloves, ear muffs must be used by the
in the foundry. In the control of health hazards due to specific workers. If the mechanical ventilation in the foundry is not
contaminant, where it has been demonstrated that the exposure adequate in removing the dust at all points of contamination,
of the employee to the contaminant is approaching the relevant the wearing of personal respiratory protective equipment,
exposure standard, or where biological monitoring indicates such as a face mask/respirator, is a complementary preventive
that an unacceptable exposure is occurring, immediate action measure together with local exhaust ventilation. If operators
must be taken to reduce the health hazard and intensive are required to work inside the enclosure, a continuous - flow,
monitoring should continue. Worker exposure to dusts, gases air - line respirator must be worn.
and vapours should be kept as low as workable. Exposures Education and Training : All employees working with foundry
should be well below the exposure standards recommended in hazards must be informed of the hazards and the precautions
the Factories Act 1948. necessary to prevent damage to their health. Employees
Engineering Control Measures exposed to contamination hazards should be educated in the
(a) Elimination/substitution and process modification viz. need for, and proper use of, facilities, clothing and equipment
quartz sand can be substituted by olivine sand in ‘sand and thereby maintain a high standard of personal cleanliness.
blasting’ as it is less hazardous. Silica - based polishing Health Assessment : Pre - placement examination and periodic
pastes should not be used in metal cleaning operations. medical examination of all worker should be done annually for
(b) Engineering controls like local exhaust ventilation early identification of health effects and for documentation for
should be provided at the mixing or mulling stage as the compensation claims.
sand is dry. It is a means of controlling carbon monoxide Noise Management Techniques :
emissions at their source. Total enclosure of abrasive and ●● Enclose the process buildings and / or insulate them
cleaning operations should be provided. Potentially irritant ●● Cover and enclose scrap storage and handling areas, as
vapours or fumes generated in core making or moulding well as shake out and fettling processes
processes should be collected by exhaust ventilation at the ●● Enclose fans, insulate ventilation pipes and use dampers
point of emission. ●● Implement management controls, including limitation of
(c) The reduction of noise at the source or in the transmission scrap handling and transport during night time. Noise
path should be achieved wherever workable. abatement measures should achieve the ambient noise
Preventing Physical Injures levels
(a) Mechanically propelled vehicles or machinery should
be inspected regularly. Contact between molten metal and Health Problems of Agricultural Workers
water must be avoided. All ladles and other equipment Agriculture is art/practice of cultivating land. WHO defines it
used for handling metal should be completely dry before as an industry comprising of all forms of activities connected
contacting molten metal. with growing, harvesting and primary processing of all types
(b) Good house keeping practices are to be followed. of crops. It also includes activities related to breeding, raising
(c) Floors around furnaces should be of slip - resistant, non - caring for animals in the farms and tending gardens and
combustible material, kept free of obstructions and cleaned nurseries. Any person engaged either temporarily/ permanent in
regularly. activities related to agriculture is called as agricultural labour.
(d) Persons would be prohibited from entering furnace areas Agricultural sector occupies a key position in our country.
when the temperature exceeds 50°C. It provides employment to about 65 per cent of the working
(e) Foundries should be equipped with safety blankets, population of India (5). It is the major source of income for
automatic emergency showers or hoses to extinguish about three - fourths of India’s populations who live in villages.
burning clothing. Agricultural workers constitute by far the largest segment in
(f) Self - contained breathing apparatus must be used in the unorganized sector. Most of them are listed as cultivators
emergencies when high carbon monoxide concentrations (large, medium and small) of whom approximately 50% belong
are suspected. to the category of small and marginal farmers. A significant
Minimizing the Risk of Heat Illness : People who have any number of them are engaged in livestock, forestry, fishing,
history of heat intolerance or a circulatory disorder, anyone orchards and allied activities. Agricultural workers constitute
• 1272 •

6. the most neglected class in Indian rural structure. Their income Others : Agriculture being labour intensive activity musculo -
is low and irregular. They do not possess any skill or training skeletal disorders are the leading cause of the occupational ill
and have no alternative employment opportunities. Socially, health (8). This risk of musculo - skeletal disorders is higher
a large number of agricultural workers belong to scheduled in agricultural workers because of the longer working hours,
castes and scheduled tribes. Therefore, they are a suppressed practice of lifting heavy weights and inconvenient work posture.
class. They are not organized and they cannot fight for their There is poor application of ergonomics principle to agricultural
rights (6). Occupational hazards of agriculture sector are given tools. There are no legislations related to health, safety and
in Table - 1 (7). welfare of agricultural workers. There is no social security for
The various types of respiratory diseases in agriculture are agricultural workers other than crop insurance. There is no act
highlighted in Table - 2. to provide welfare to the workers. Living condition of these
people, low educational status, lack of medical facilities in
Table - 2 : Respiratory diseases in agriculture rural areas aggravate there problems. Being in close proximity
to animals agricultural labour also faces hazards of zoonosis.
Agent Disease
Women in Agriculture
Saw dust Carcinoma nasal septum
Women in India are the major work force in agriculture and
Sugar cane dust Bagassosis perform almost all the agricultural activities. Since agriculture
Cotton, flax, sisal or hemp Byssinosis by its nature is an unorganized sector and in case of women, their
contribution is generally unrecognized. In fact some economist
Husk with thermophilic Farmer’s lung
have use the term ‘Labour for Love’ while describing the status
actinomycis
of Indian women who is married with farmer’. A significant
(Micropolyspora faeni)
proportion of women work force in rural areas is dependent
Tobacco dust Tobaccosis for their livelihood (8). The lives of these women are plagued
Dusts of grains, rice, coconut Asthama, COPD by high levels of occupational, poverty - induced diseases and
fibres, tea reproductive health problems. Abortions, premature delivery,
and still birth are outcomes of their deprived socio - economic,
Cocoa bean handling Respiratory allergy
Table - 1 : Occupational Health Hazards of Agriculture
Exposure Health Effect Remarks
Dehydration, heat cramps, heat exhaustion, heat Most agriculture occupations are performed
Weather, Climate
stroke, skin cancer outdoors
Snakes, insects Fatal or injurious bites and stings Close proximity in high incidence
Injuries ranging from cuts to fatalities, hearing Most farm operations require variety of skills for
Sharp tools, farm
impairment from loud machinery which workers have little formal training and there
equipment
are few hazard controls on tool equipment
Numerous types of (largely unreported) Agricultural work involves awkward and
Physical labour
musculoskeletal disorders, particularly soft - tissue uncomfortable conditions and sustained carrying of
carrying loads
disorders, e.g. back pain excessive loads
Acute poisonings, chronic effects such as More hazardous products are used in developing
Pesticides neurotoxicity, reproductive effects and cancer countries with minimal Personal Protective
Equipment (PPE)
Irritation of the eyes and respiratory tract, allergic Agricultural workers are exposed to a wide range
Dusts, fumes, reactions, respiratory diseases such as Byssinosis, of dusts and gases from decomposition of organic
gases, particulates bagassosis, asthma, chronic obstructive pulmonary materials in environments with few exposure
disease and hypersensitivity pneumonitis controls and limited use of PPE use in hot climates.
Skin diseases such as fungal infections, allergic Workers are in direct contact with environmental
reactions and dermatoses pathogens, fungi, infected animals and allergenic
plants
Parasitic diseases such as schistosomiasis, malaria, Workers are in direct contact with environmental
Biological agents
sleeping sickness, leishmaniasis, ascariasis and pathogens, fungi, infected animals and allergenic
and vectors
hookworm plants
of disease
Animal - related diseases or zoonoses such as Workers have ongoing, close contact with animals
anthrax, bovine tuberculosis and rabies (at least through raising, sheltering, and slaughtering
40 of the 250 zoonoses are occupational diseases exposed to a mix of biological agents, pesticides,
in agriculture) and diesel fumes, all linked with cancer
• 1273 •

7. cultural, and political conditions and gender inequities (9). The from money lenders to buy costly fertilizers and pesticides. The
socio - cultural norms and practices that endanger the women’s general public health system of the country is also in a poor
health are reflected in their low age at marriage and low age at state and has very little to offer as preventive, promotive and
first childbirth. Women working in fields shoulder the double curative care to this class. This is evident from the large number
burden of work - within home and outside home - and stretch of suicides that have taken place among farmers. There is a
themselves beyond their physical capabilities to procure definite need to take case for social security for this sector. In
adequate economic security for their families. They bear the this connection government has come out with National Policy
brunt of the deprivation due to the gender inequities. The low for Farmers 2007(10). The objective of the policy is to improve
nourishment and the resultant general under - nourishment the economic viability of farming through substantially
lead to illnesses, which prevent them from translating their improving net income of farmers. The policy emphasis on
labour endowments into economic resources. In short, the increased productivity, profitability, institutional support, and
poverty of the women agricultural workers encompasses a wide improvement of land, water and support services apart from
rage of unmet needs and gender - specific inequities including provisions of appropriate price policy, risk mitigation measures
lack of adequate access to education, employment, resources as and so on. Government of India has recently taken several
well a range of violence, relative powerlessness, and feelings of initiatives such as the National Horticulture Mission, the
hurt, low self - esteem and denial of identity. National Bamboo Mission, reforms in agricultural marketing,
Legislations the revitalization of cooperative credit structure and setting
up of the National Fisheries Development Board and the
Though agriculture is the major occupation in India and gives National Rainfed Area Authority. More recently, the National
not only employment but is also responsible for providing food Food Security Mission and the Rashtriya Krishi Vikas Yojana
security to the nation but unfortunately only lip service has (Additional Central Assistance Scheme) have been approved to
been paid in providing social security for the welfare of the substantially enhance investment in agriculture and increase
workers engaged in this class. As a result they can go into production and productivity.
penury due to floods, droughts, extensive loans under taken
for all dust damage to the alveolar part of lung including the
Organ / System Diseases Peculiar
225 to Occupational Settings
airways which do not have mucociliary lining (18). Therefore
the term does not include bronchitis, asthma or cancers. In
other words the inorganic dusts like silica, asbestos and coal
Leo S Vaz, Ashok K. Jindal & Puja Dudeja cause pneumoconiosis where as organic dust like cotton and
cane sugar cause bronchitic changes and do not qualify to be
called pneumoconiosis.
Occupational Lung Disease Body Defence Mechanism : Dust is an aerosol consisting of
An occupational lung disease is a lung condition that develops finely divided particulate matter, size 1μ- 150μ, organic or
as a result of a person inhaling harmful substances at his or her inorganic, generally inanimate and produced by attrition of
place of work. Occupational lung diseases are the most common solid matter by processes such as cutting, sawing, crushing,
work - related illness but fortunately many are preventable or grinding, blasting etc. Dust particles 10μ or more in size are
controllable with proper treatment. Occupational lung diseases released in size settle down on the floor due to effect of gravity.
are classified into two major groups : pneumoconiosis, caused The dust particles of such larger size which are inhaled are
by dust that gets into the lungs, and hypersensitivity diseases, mostly arrested by the upper airway filter of hairs in the nostrils
such as asthma, that are caused by the lungs’ overreaction and by the folds of mucosa over the turbinates and carried down
to airborne pollutants. Table - 1 depicts important features of in the mucus and swallowed over airway filter, carried in the
various lung diseases. mucus back to the larynx and swallowed. Irritant particles are
Pneumoconiosis thrown out by reflex acts of coughing and sneezing. Of smaller
particles those are inhaled in size of 3 - 10μ are tackled by the
By ILO definition it is the accumulation of dust in the lung
mucociliary lining of lower airway, filter, carried in the mucus
and tissue reaction to its presence. The concept of using the
back to the larynx and are swallowed. Particles 0.5μ - 3μ in size
term pneumoconiosis has undergone a change. Earlier this
reaches the alveoli and get deposited causing damage to the
term was used to describe all lung related problems caused
lungs, producing various types of pneumoconiosis. Particles
by any kind of dust (17). However the term should be used
less than 0.5μ in size have a slim chance of settling down in
• 1274 •

8. Table - 1 : Comparison of Different Types of Lung Diseases
Farmers’
Silicosis Anthracosis Asbestosis Byssinosis Bagassosis Siderosis
lung
Type Major Major Major Major Major Major Major
Occupational Silica dust Coal miners Asbestos Exposure to Fibrous Agricultural Foundry
exposure mines, and handlers industry; cotton dust residue workers workers,
tunnels : : carbon brake and released of sugar grinders and
quarries, electrode fire resistant during cane in welders
foundries; manufacturing product cording, cardboard
potteries manufacturing spinning and and paper
and soap weaving industry
Initiating Chemical Unknown Mechanical Allergy Infection Infection Absent
stimulus
Pathogenesis Fibrosis Two distinct Asbestos fibres Cotton dust Fungal Fungal No tissue
initiated by stages - simple initiate fibrosis inhalation infection infection reaction or
silicic acid CWP and of pulmonary produces leading leading to functional
leading to PMF. Average tissue, allergic to acute bronchitis impairment
nodular time taken emphysema reaction bronchitis and broncho though
fibrosis, is 12 years and its leading to and - pneumonia lungs are
emphysema associated broncho broncho - loaded with
and right complication - spasm, pneumonia iron dust.
heart emphysema
failure. and its
Pulmonary complications
TB in 50%
cases
the lungs and are mostly breathed out in the expiratory air. be taken to see if the individual has pulmonary tuberculosis
Silicosis : Silicosis is a disease caused by breathing air or any other lung disease. Basic lung function tests should
containing silica in its free state, as quartz (SiO2). The be carried out, including measurement of the Vital Capacity
pathological result is a generalized fibrotic change and & Forced Expiratory Volume in one second. Dust control is
development of miliary nodules of variable sizes in both lungs. the most important engineering procedure to reduce risk. If a
The clinical manifestations are shortness of breath, decreased significant number of workers develop silicosis within 20 - 25
chest expansion, a lessened capacity for work and chronic years of first employment, the dust control measures should be
bronchitis with the absence of fever and characteristic X - ray suitably revised.
findings. There is an increased susceptibility to tuberculosis. Asbestosis : Asbestos is a fibrous material. These are silicates;
The diagnosis of the disease mainly depends upon occupational silica combined with bases like magnesium, iron, calcium,
history symptom complex and the radiological findings. The sodium and aluminum. These are of two types - serpentine
pathological process starts only when the dust particles, which and amphibole. However, 90% of production is of serpentine
contain silica in a free state such as quartz (SiO2), reach the variety. Asbestos used in the manufacture of asbestos cement,
alveoli. Most of the dust inhaled is expelled by the ciliated fireproof textiles, roof tiling, brake lining, gaskets, and such
epithelium and some part is eliminated by phagocytosis, which other items. Asbestos fibres are inhaled and fine dust gets
brings up the particles and discharges them to the ciliated deposited in the alveoli. These are insoluble and cause chronic
epithelium and the cough mechanism expels them. However, irritation resulting in pulmonary fibrosis of lungs. It can also
when the fine particles are present in the atmosphere in a large cause carcinoma of bronchus and mesothelioma of pleura and
quantity, some find way to the finer air passages. They first peritoneum (more due to amphibole variety). These possibilities
cause the inflammation of the ciliated epithelial cells with are more when exposure is coupled with smoking. The disease
their subsequent destruction, reducing the first line of defense. appears after an exposure of 5 to 10 years. The fibrosis is
Epithelial cells crowded with silica dust get aggregated into peribronchial, diffuse and more near the bases in contrast to
definite clumps around which fibrosis occurs. This damage fibrosis due to silicosis. Clinically, patient gets cough, pain in
produced in the lung is permanent. It is liable to activate the chest and dyspnoea disproportionate to the clinical signs in
preexisting tubercular focus and develop tuberculosis. The lungs. In advanced cases, there may be clubbing of fingers,
disease finally produces emphysema and corpulmonale. cardiac failure and cyanosis. Sputum show asbestos fibres
Very little can be done once the disease has set in and therefore, coated with fibrin called “asbestos bodies”. X - ray chest shows
prevention is most important, pre - placement & periodic health a ground glass appearance in lower parts of lungs. Disease
examinations of the worker are important. Chest X Ray is to is progressive even after removal from exposure. Preventive
• 1275 •

9. measures include : It is associated with breathlessness, clubbing, bronchitis,
(a) Adopt all measures for dust control. The legal exposure emphysema and right heart failure. This condition may be due
limit in India is 23 fibres/ml of air. Fig.-1 shows various to quartz, coal mine dust plus rheumatoid arthritis (as seen
methods of dust control. by Dr. A Caplan in 1953 in New South Wales Coal mines).
(b) Substitute it with safer materials like glass fibres, calcium Progressive massive fibrosis is characterized by formation of
silicate, plastic foam etc. where feasible. a mass 3 - 10 cm or more in length in the lung tissue and
(c) Use safer varieties of asbestos (chysotile and amosite). lying parallel to the pleura : this may cavitate after many years
(d) Periodic medical examination of workers and elimination releasing large quantities of black necrotic tissue and dust
of susceptible from workforce. which is coughed out as an expectorant resembling black ink
(e) Use of personal protective measures. (melanoptysis). Control measures centre on dust control and
(f) Good housekeeping & the use of vacuum cleaners. early detection of the disease.
(g) Use of respirators & protective clothing is to be In X - rays, 3 stages are seen in simple CWP First stage -
.
encouraged. Generalized mottling of the lung through which exaggerated
(h) Health education of the workers. lung markings are seen. Second stage - Mottling becomes very
(j) Continuing research to find out safer substitutes (19-24). dense and exaggerated lung marking cannot be seen through
Anthracosis or Coal Worker’s Pneumoconiosis : (Synonyms: them. Third stage - Very dense reticulated opacities seen all
Anthracosis, Coalminer’s consumption, phthisis melanotica, over the lung. The reticular markings indicate coal dust foci
black spit). The diseases due to inhalation of dust in coal around the tips of the bronchioles. A person suffering from
mines are simple coal - worker’s pneumoconiosis (CWP) and silicosis is both breathless and ill but a person with CWP is
complicated coal - worker’s pneumoconiosis. Simple CWP is breathless but does not look ill. It has been seen that there
due to chronic exposure to coal dust with a low level of other is a negligible risk of developing CWP over a working lifetime
mineral dust contamination. In this condition, the progression with a dust level below 2mg/cu.m. The basic lesion of CWP
of small rounded opacities may be associated with only a is the local macule. Air spaces adjacent to the macule get
slight loss of ventilation, which is insufficient to produce any enlarged, consistent with focal emphysema. A small percentage
disability. It can be very difficult to differentiate these effects of miners develop complicated CWP or PMF diagnosed
from those of aging and cigarette smoking. Complicated CWP is radiologically by the appearance of a density 1 cm or greater.
one in which CWP is complicated by the additional pathology of Recent studies suggest that superoxide anion generation by
large masses of solid tissue within the lung parenchyma. The alveolar macrophages may play a role in the lung injury of
condition usually occurs after 20 - 30 years in the occupation. CWP The introduction of improved ventilation, water spraying
.
Fig. - 1 : Methods of Dust Control
Methods of Dust Control
Medical Control Environmental Control Personal Control
 Proper selection of persons Dust control at the  Personal hygiene
for dusty trades source Control  Respiratory protection
 Periodic medical (Dust respirator, Air
examination Prevention of escape of mask supplied with air)
 Epidemiological analysis dust into atmosphere
Change in Process Control by substitution  Segregation  Segregation
 Rotary diamond drills  Silica carbide/aluminum  Proper enclosure  Proper enclosure
in place of pneumatic grinding wheels instead  Ventilation general &  Ventilation general &
drills (in mines place of sand stone wheel exhaust exhaust
 Use of permanent  Ground flint replaced by  Reduce magnitude of  Reduce magnitude of air
mould in Foundry non-silica substitute in air displacement by displacement by review
 Use of plastic sand pottery making review of design of of design of process
mixture to form moulds  Silica free parting process equipment equipment
in foundry compounds in iron  Plant layout  Plant layout
 Use of dust free flint in and steel industry  Segregating of dust and  Segregating of dust and
glaze of potteries in  Abrasive blasting non-dusty operations. non-dusty operations.
place of quartz mixture replaced by wheel shot  No crowding  No crowding
 Wet grinding of blasting  Mechanization  Mechanization
washing quartz Good house keeping  Good house keeping
• 1276 •

10. and mechanized equipment has greatly reduced dust levels in asbestos), a biological agent (such as hepatitis B virus), or an
the mines. Medical surveillance is the second most important industrial process in which the specific carcinogen may elude
measure to prevent disabling CWP . precise definition (such as coke production) (13). Common
Other Lung Diseases occupational carcinogens include Benzidine, 2 - naphylamine,
Arsenic, Beryllium, Cadmium, Chromium, Nickel, Asbestos,
Byssinosis : Bronchopulmonary diseases caused by exposure Silica, Talc containing asbestiform fibres, Wood dust, Benzene,
to airborne dust of cotton, flax & soft hemp leads to Byssinosis. Trichloroethylene (TCE), Polychlorinated Biphenyls (PCBs) and
It is a chronic respiratory disease characterized by tightness of Ethylene oxide.
the chest & breathlessness at work after the weekend or other
absence. It is also called ‘Monday Fever’. This is probably due Prevention
to a histamine releasing substance. In addition to histamine Occupational cancers have two characteristic features namely
release, exposure to cotton dust causes irritation in the upper they are preventable (14) and most occupational carcinogens
respiratory tracts & bronchi, which after prolonged exposures have first been recognized by clinicians (15).
slowly progresses to chronic obstructive pulmonary disease. Primary Prevention
In early stages there may be decline in FEV1, which may be ●● Recognising presence of hazards and risks
symptomless in some workers. Within, one or two days, most ●● Educating management and workforce
symptoms tend to disappear except for irritation in the upper ●● Eliminating exposure by substitution and automation
respiratory tract. As the disease progresses, the chest tightness ●● Reducing exposure by engineering controls (such as local
is accompanied by breathlessness, the symptoms becoming exhaust ventilation and enclosure), changes in handling,
worse & persisting for a longer time. In its late stages the and altering physical form in processing
diseases resembles chronic bronchitis & emphysema, except for ●● Monitoring exposure and maintaining plant
the history of chest tightness & decline in ventilatory capacity, ●● Protecting workers by means of personal protective
characteristically worse at the beginning of the work week. equipment
Chest X - rays do not show any specific changes. Prevention ●● Limiting access
includes Pre - placement examination, which should include ●● Providing adequate facilities for showering, washing, and
Chest X ray, VC and FEV1. Periodic medical examination is changing
recommended every year. In groups of workers, a drop of more ●● Legislative provisions
than 10% in FEV1 during the work shift on the day after the
Secondary Prevention : A secondary approach to prevention
weekend holiday may provide advance warning that workers
consists of detection at an early stage to prevent the further
are liable to develop Byssinosis.
progression of diseases and increased survival by institution
Occupational Asthma : Occupational asthma is a form of of treatment. Screening tests and medical surveillance - for
lung disease in which the breathing passages shrink, swell, example, exfoliative urinary cytology and skin inspections.
or become inflamed or congested as a result of exposure to
irritants in the workplace. Occupational asthma is a lung Occupational Dermatoses
disorder characterized by attacks of breathing difficulty, An occupational dermatitis is one where the inflammatory
wheezing, prolonged exhalation, and cough, which is caused reaction is caused entirely by occupational contact factors or
by various agents found in the work place. where such agents are partly responsible by contributing to the
Hypersensitivity Pneumonitis : Hypersensitivity pneumonitis reaction on compromised skin. The commonest site is hands
is an inflammation of the lung (usually of the very small followed by forearms. In case of airborne contact dermatitis
airways) caused by the body’s immune reaction to small air - face may be the prime site on inflammation. Contact dermatitis
borne particles. These particles can be bacteria, mould, fungi, accounts for at least 60% of occupational skin disease, which, in
or even inorganic. Hypersensitivity pneumonitis is usually turn, account for 40 - 70 % of occupationally acquired illness.
an occupational disease in which exposure to organic dusts, Causes
fungus, or moulds leads to acute and over time, chronic lung
1. Physical agents : Heat, Low Humidity, High Humidity,
disease.
Cold, Pressure, Vibrations, Friction (Coal Mines, Construction
Berylliosis : Berylliosis (or beryllium disease) is caused by the Workers) and Occlusion, Presence of Sharp Particles (Fibre
inhalation of beryllium particles, dust or fumes. Its symptoms Glass), Damage from Minor Lacerations of the Skin, Solar
include coughing, shortness of breath, fatigue, weight loss or Radiation, Ultraviolet Radiation, Ionizing Radiation.
loss of appetite, fever and sweating. Medical tests may reveal
2. Biological Agents : Bacteria, Viruses, Fungi (Confectioners
abnormal lung sounds, lung scars, decreased pulmonary
- Monilia, Sewage Workers, Doctors), Parasites (Miners and
function, granulomas (a nodular form of chronic inflammation)
Workers in tea gardens - Ankylostomiasis).
and an allergy to beryllium.
3. Chemical Agents : These account for 70% of all occupational
Occupational Cancers dermatoses and include :
Occupational cancer is any malignancy wholly or partly caused ●● Acids : HCl, HNO3, H2SO4
by exposures at the workplace or in occupation. Such exposure ●● Alkalis : Hydroxides, Carbonates of Sodium, Potassium
may be to a particular chemical (such as ß - naphthylamine), and Ammonium
a physical agent (such as ionising radiation or a fibre like ●● Chlorides : Sulphuryl Chloride, Arsenic Chloride, Stannous
Chloride
• 1277 •

11. Some examples of substances causing occupational 2. Employer and employee should be aware of the potential
dermatitis are : risks of exposure
●● Rubber accelerating chemicals, such as Thiurams and 3. Education of need for good occupational hygiene
Carbamates 4. Adequate provision of suitable and effective means of
●● Biocides - such as Formaldehyde reducing exposure
●● Hairdressing chemicals - such as Thioglycolates, 5. Awareness of limitations of personal protection devices
Phenylediamine 6. Engineering or environmental control. Few examples are
●● Epoxy resin monomers given below :
●● Chromates ●● Substitution of mineral oil by vegetable oils
●● Plant allergens - such as Sesquiterpene Lactones found in ●● Segregation and mechanical handling of radioactive
Chrysanthemum substances
Diagnostic Criteria ●● Local exhaust ventilation - chromium plating
●● Good general ventilation
1. Disease appears during a period of occupational exposure
●● Good housekeeping - mercury and its compounds
or within a reasonable period of time after the exposure
●● Safe design of the plants
ceases
●● Provision of adequate bathing and washing facilities
2. Occurs first on the exposed part
●● Provision of protective clothing
3. Disease has not been present previously
●● Periodic environmental survey to ascertain TLV
4. Disease improves after the termination of exposure
●● Wet methods
5. Disease recurs after exposure
7. Medical methods
6. Morphology of the disease is similar to the well known
cases resulting from similar exposure and other fellows (i) Pre - placement medical examination : careful and
with similar exposure similarly affected. detailed history to exclude allergic tendencies such as eczema/
Types asthma. Such people may not be employed in occupations with
sensitizers.
Occupational dermatitis is commonly of two types Irritant
contact or Allergic contact Dermatitis. Others are contact (ii) Standardized Patch Test
urticaria, rubber latex protein sensitivity and photo contact a) Test substances appropriately diluted. Standardized kits
dermatitis. available.
b) Apply the patch to the upper or mid back.
Management c) Leave the patch in place and keep dry for 2 days before
1. Detailed occupational history removing.
2. Evaluation of contact factors d) Read tests :
3. Patch test followed by recommendation on reducing or ●● The same day that patches are removed
stopping exposure to the offending agent and similar ●● One additional reading 3, 4, or 7 days after test initially
ones. applied
4. Chemical analysis of environmental materials to determine e) Grade test reactions according to intensity : 0 = no reaction
whether they contain a substance to which the patient is to 3+ = small blisters
patch test positive. Relate relevance of positive reactions to clinical dermatitis
Prevention cautiously. Careful history and review of skin exposures must
1. Primary prevention is aimed at providing appropriate establish significance.
information and protection. (iii) Treatment : Treatment with barrier / moisturizing creams,
topical steroids, oral steroids and antibiotics if required.
• 1278 •

12. (h) East and comfort with which it can be used and freedom
226 Industrial Accidents of movement with equipment which should not hamper
performance of the worker
(i) Maintenance of these equipment
Ashok K. Jindal, Leo S. Vaz, Puja Dudeja
(j) Periodical check up
(k) Good earthing
The most important industrial hazard due to machinery is
the accidental injury. A detailed account of the prevention Safety Audit
of industrial accidents is outside the scope of this book. Objectives
Box - 1 depicts epidemiology of industrial accidents, while (i) Critically evaluate the safety programme
Fig. - 1 shows methods of accident prevention. (ii) Evaluate the systems to identify and control hazards
The first step in any accident prevention programme is (iii) Check that the above system meets the statutory standards
elimination of various hazards whilst designing the process. and codes of practice
If this is not possible, the next best step would be to control Benefits
the physical, mechanical and chemical hazards in work
(i) Strengthening of the Organization safety standard and
environment by suitable engineering design. But when this
programme.
also is not possible or is not able to give full protection to
(ii) Improve the skill and performance of employee and
workers the third line of defence has to be resorted i.e., the
managers.
personal protective equipments. These protective equipments
(iii) Helps to create group and self awareness and provides
cannot eliminate hazard or stop an accident taking place. These
motivation.
equipments merely set up a barrier against the hazards thereby
(iv) Identifies specific deficiencies in the safety programme.
preventing or minimizing an injury.
(v) Provides timely information before any injury producing
In selection of these equipments, the following points are to be incident occurs.
borne in mind : Mechanism
(a) Type of hazard to be faced
Safety audit shall be carried out at three levels
(b) Selection of right type of personal protective equipment
(c) Availability of correct equipment in good condition at the (i) Level - 1 : Internal Audit inspection by Safety Officers from
work spot within the factory once in every three months.
(d) Training of workers to use the equipment (ii) Level - II : Audit inspection by a group comprising of 3
(e) Convincing the workers that the equipment is used will officers of the factories in the concerned group, once in a period
protect them from hazard of six months.
(f) Making it a habit with the worker to use the equipment, (iii) Level - III : Annual Audit inspection by the Regional
(g) Degree of protection needed Controller of Safety / O.F. Board.
Box - 1 : Epidemiology of Industrial Accidents
Host factors Agent factors Environment factors
●● Age ●● Improper planning and Physical
●● Sex construction of factories ●● Overcrowding
●● Experience and education ●● Machines ●● Defective lighting
●● Concomitant disease ●● Faulty design ●● Temperature
●● Psychological factors ●● Lack of maintenance ●● Ventilation
●● Personality Traits/ ●● Entanglement of loose ●● Humidity
Emotional stability clothes and hair ●● Radiations from surroundings
●● Wearing unsuitable shoes ●● Transmission of Machinery ●● Pressure
●● Carrying improper loads ●● Speed of Work Processes ●● Noise
●● Faulty stepping ●● Faulty planning ●● Vibrations
●● Not using personal ●● Boiler explosion ●● Ionizing Radiation
Protective measures ●● Dust explosion ●● Slippery Floors
●● Physical defects ●● Corrosive materials ●● Uncovered drains
●● Molten metal and Hot liquids Social
●● Flying solid particles ●● At work place
●● Metal grinding ●● Domestic
●● Stone dressing ●● Relationship between
●● Riveting workers and management
●● Chipping metal ●● Lack of Safety Policy
●● Electricity
●● Gassing
• 1279 •

13. Fig. - 1 : Prevention of Industrial Accidents
Prevention of Industrial Accidents
Role of Personal Good Working
Planning Processing
management protection Environment
Foreman and Industrial MO Role of ILO Legislation
safety and safety Machines
 Design and  Clear Policy  Precautions against  Clothing  Lighting
Construction of  Safety Committee toxic Fumes, gases  Dust  Thermal Comforts
factory  Job Analysis of each and Dust vapours  Masks  Noise control
 Collaboration Worker  Substitution  Respirator  Vibration Control
 Industrial MO  Supervision  Segregation  Proper Weight lifting  Radiation Control
 Safety Officer  Training of New  Exhaust Ventilation  Precautions against
 Chemist Worker/trainee  Periodic MAC Fire & Electrocution
 Industrial Hygienist  Industrial Fatigue  Checks of Equipment  Good house keeping
 Supervisor  Avoid Long hours
 Engineer  Posture
 Personnel Officer  Preventing Boredom  Collection & Utilization
 Welfare Officer  Recreation of Information of Special
 Guards
 Union Leader  Welfare Services Dangers in Industry
 Painting of Dangerous
• 1280 •
 Social Worker  Methodological
Parts
Investigation of Physical
 Maintenance
and Psychological
 Proper Training  Medical Examination Causes
 Supervision  Psychological Test  Standardization of
 Education of Workers  Physical Check of Statistics
on Shop floor Environments  Prescribing safety By-
 Accident  Statistics of Accidents laws
Investigation  Engineer Designing /  Research
 Research setting Machinery  Publicity material
- Engineering  Investigation of  Encourage safety
- Medical Accidents measures
 Human Behavior  Health Education
Training
 Personal Protective
equipment

14. Scope where accidents are due to unsafe conditions. In case of all
The Audit is necessarily very wide ranging in scope and serious accidents, a Board of Enquiry to investigate in to the
covers all aspects of a company’s operations. Some of the accident shall start investigation immediately on receipt of
broad areas to be covered for Safety Audit are to study, in intimation by visiting the accident spot so that the evidence
detail, the Safety Policy, Process Safety, Fire Safety, Hazards is not tampered. Photographs may be taken if necessary. The
in the processes and their control, Pollution control, Machine investigations should be towards fact finding and not fault
guarding, Housekeeping, Material Handling system, Training finding. The concerned sections shall not disturb the site until
of workers/supervisory staff and Management personnel, it is cleared by the board of Enquiry of Safety Officer.
Accident reporting, investigation & analysis, Emergency Accident Returns & Analysis : The accident statistics
preparedness and availability of Health, First Aid, Periodical indicating details of accidents, man days lost, man hours
Medical examination. worked are compiled quarterly. A monthly report on the
Accident Investigation : All accidents should be investigated accidents taking place during the preceding month is also
by the concerned Heads of Sections and an unambiguous compiled. Any accident taking place in the factory shall be
report sent in Form No. 14. Safety section shall investigate analyzed by Safety Section.
selected accidents involving plants/machineries/chemicals
and produces ill effects much more rapidly and probably in a
227 Industrial Toxicology more severe from than when ingested. Young persons are more
prone to lead poisoning than adult. Lead concentration in the
working atmosphere should be kept below 2.0 mg per 10 cu m
Ashok K. Jindal & Puja Dudeja
of air ( 25 - 31).
Symptoms : The commonest manifestations of lead poisoning
Industry uses and manufactures wide variety of substances,
are blood changes and lead palsy. Lead makes the RBC fragile
which are either known or suspected to cause toxic effects
and causes haemolysis, which results in anaemia with
in the persons working with them. Industrial toxicology
compensatory stimulation of the bone marrow. So immature
is concerned with the study of various substances used in
RBC or reticulocytes appear in the blood. The RBC count is
industry either as media for processing some other materials
generally below 3 million with haemoglobin under 70 percent
or as raw materials or the finished product. The Permissible
(Sahli). In ‘Lead palsy’ there is a typical degenerative neuritis
Exposure Limit (PEL) to a substance is defined as exposure to
and subsequent fibrosis. In acute lead encephalopathy, there
a maximum time weighed average (TWA) of concentration of a
is involvement of the meninges with oedema and increased
toxicant for an 8 - hour work. The Threshold Limit Value (TLV)
intracranial pressure. There may be some capillary damage as
is that limit in an environment of a toxic agent or the substance
well. The lead line showing blue discoloration of the margins
or the deleterious material which when inhaled by a worker
of the gums is a classical sign. A diagnosis of lead poisoning
for a duration of 8 hours per day for indefinite periods will not
should be based on clinical finding, biochemical evidence of
cause any harmful effects.
excessive lead absorption and by evidence of unusual exposure
Details of industrial toxicology in respect of common and (See Table - 1 and 2).
important toxic substances are being described in this chapter.
Prevention : It depends on good housekeeping, personal
The general measures of prevention and control are dealt with
protection and education of workers and medical supervision
subsequently.
for the detection of hazards the occurrence of poisoning
Lead followed by its rectification.
Lead is ubiquitous in industry and poisoning due to absorption (i) Exhaust ventilation measures so arranged that whatsoever
of lead and its compounds is still common. Lead is the most position the worker assumes the lead dust and fumes are
commonly used metal in industries because of anticorrosive drawn away from his face.
property. Hazardous process are lead smelting, burning and (ii) Strict periodical inspection of the exhaust system : All
making paint, painting, welding riveting, battery manufacture, ducts and their angles should be cleaned periodically.
and lead baths connected with heat treatment of metals, (iii) Avoidance of crowding in the workrooms where metallic
specially when carried out in confined spaces. Inhalation of lead is heated.
lead dust and fumes is the chief route of poisoning, the next (iv) The floor should be impervious to water, and smooth so
common route is ingestion, cutaneous absorption is rare. It that no lead dust can accumulate.
is rapidly absorbed into general circulation when inhaled (v) The floor should be constantly kept wet & swept before
• 1281 •

15. Table - 1 : Manifestations of Lead Poisoning
System Evidence of absorption Evidence of incipient poisoning Evidence of definite poisoning
General Restive, moody, easily Pallor, Leadline, Jaundice Anemia, Leadline, Jaundice,
appearance excited, emotional, lead line Emaciation, “Premature ageing”
Persistent Metallic Metallic taste, definite anorexia, Metallic taste, increasing anorexia, nausea
Digestive
taste, slight anorexia slight colic, constipation and vomiting, marked colic, rigid abdomen
System
slight constipation marked constipation, blood in stool
Slight headache, insomnia, slight Severe headache, increased insomnia,
dizziness, palpitation, increased increased dizziness ataxia, confusion,
Nervous Irritability, irritability, increased reflex marked reflex changes, tremor, fibrillary
System uncooperativeness twitching, neuritis, visual disturbances,
encephalopathy hallucinations,
convulsions, coma paralysis.
Muscle soreness, easily fatigued General weakness, arthralgia,
Miscellaneous -
hypertension
Urine Abnormal lead content Abnormal lead content, Abnormal lead content, Albumin,
examination Albumin, Casts Casts, Porphyrinuria, Haematuria
Polycythemia, Normal red cell count and Decrease in haemoglobin, decrease in
polychromatophilia, haemoglobin, reticulocytosis 50 RBC, increase in cells showing basophilia,
Blood
increase platelets, - 100 stippled cells per 100,000 anisocytosis and poikilocytosis, decreased
changes
reticulocytosis, RBC, abnormal blood lead platelets, increase in blood lead
abnormal blood lead
Table - 2 : List of Bio-Chemical Tests
Excessive absorption
Acceptable absorption
Test Normal Population occupation with
in occupation
signs & symptoms
Blood lead 10μg/dl 75 μg/dl >80μg/dl
Urinary lead 10-65μg/g Cr Upto-150 μg/g Cr >150 μg/g Cr
Zinc protoporphyrin 16-35 μg/dl Upto 100μg/dl >100 μg/dl
Urinary delta aminolaevulinic acid 5 mg/g Cr 6-20 mg/g Cr >20mg/g cr
and after the day’s work with a vacuum cleaner. by active treatment.
(vi) Workers should wear special work clothes which should Treatment : When lead poisoning is diagnosed, the further
be removed before leaving the factory and deposited in exposure should be discontinued, the use of penicillamine and
specially provided lockers in order to ensure the prevention Ca - EDTA, chelating agents, help in bringing down the blood
of contamination of private clothes. lead levels by promoting lead excretion in urine. A saline purge
(vii) Suitable respirators against lead dust and fumes should be will help to remove unabsorbed lead from the gut and also will
use and inspected regularly. relieve constipation.
(viii) No food, drink and tobacco should be taken in a place
Tetraethyl Lead
where there is a risk of lead poisoning - special rooms
should be provided for this in factories. Exposure to high concentrations of vapour of leaded petrol,
(ix) Personal cleanliness should be ensured by providing especially in hot weather, is responsible for an acute form of
bathing and washing facilities. lead poisoning (lead encephalopathy). In industry this hazard
(x) Health education to avoid dusts and fumes of lead being occurs by spillage in petrol filling sheds/holds/barges with
inhaled or ingested. inadequate ventilation, inhalation from clothing saturated
(xi) Medical surveillance : Pre-employment medical scrutiny of with petrol from spillage and splashing and absorption
the prospective workers in the hazardous process should through the skin, which is relatively sight. In some cases a
include the history of previous exposure to lead and chronic form of lead poisoning occurs. Proper ventilation of the
elimination of those with a positive history of symptoms shed is important. The operation of filling should be carried
of lead poisoning. Quarterly medical examination during out in the open air. Exhausted fans may be necessary. Special
employment with attention paid to the loss of weight, precautions must be adopted when containers are loaded in
gastrointestinal symptoms, weakness of wrist muscles and the holds of the barges. Only containers in sound condition
blood picture, removal from exposure should be followed should be accepted for loading and care should be taken in the
• 1282 •

16. storage of the containers. The holds of the barges /tanks should frequently. Shower bath and a change of clothing should follow
be provided with adequate ventilation. Short shifts at frequent the day’s work. All cuts, abrasions and other injuries on hand
intervals during the work and overall turnover of the labour, so and forearm should be protected by adhesive strapping before
that each man is employed for one week in four on this work, starting work. The forearm should be inspected twice a week
are essential preventive measures. Other precautions are the and any breach of continuity of the skin should be immediately
same as have been described under lead poisoning with the reported to the factory doctor. A protective ointment should be
current trend on use of unleaded petrol; it is presumed that applied in the nostrils.
toxicity due to this cause will be on the decline. Metal Fume Fever
Phosphorous It is an transient illness and is commonly known as ‘Brass
White Phosphorus (WP) Founders Ague’ ‘Zinc Fever’ or ‘Metal Chill’. It follows the
inhalation of high concentrations of finely dispersed zinc
White phosphorus (WP) is being used in smoke producing or brass fumes, usually in the form of oxides. After heavy
ammunition. After white phosphorus exposure burnt skin is exposure, the nose and throat feel dry and sore giving rise to
washed with 5 % sodium bicarbonate and 3 % copper sulphate a dry cough. In a few hours, the symptoms appear. There is
in 1 % hydroxy ethyl cellulose. Phosphorus particulars become shivering which may last for some time and this is followed by
coated with black cupric phosphide allowing easy identification. profuse perspiration, the picture simulating that of an attack
Copper sulphate also decreases rate of underlying tissue. Since of malaria. Considerable prostration follows the attack, but by
blackened particles continue to elicit tissue injury, they can the next morning recovery is almost complete. Some degree of
be removed. Of late, copper sulphate is found to be toxic and insusceptibility is produced by low - grade inhalation but is
systemic copper poisoning can manifest as vomiting, diarrhea, lost in 48 hours. Workers therefore, are likely to suffer more
oliguria, haematuria, hepatic necrosis and cardio - pulmonary on Monday morning; Metal fumes should be eliminated by
collapse. proper exhaust ventilation. When conducting replacement or
Mercury transfer medical examinations, cases with a history of chronic
bronchitis, asthma or any other respiratory trouble should be
Mercury Fulminate withheld.
It is a brownish yellow, heavy, crystalline solid prepared by
the action of alcohol on mercuric nitrate. The chief hazard Mineral Oils
is dermatitis affecting those who are employed in filling Mineral oils are insoluble and soluble. The insoluble ones are
operations where a fine dust is raised, which comes in contact used mainly as lubricants for cutting tools and the soluble ones
with the naked skin. The susceptibility of some individuals are used as cooling agents. Cutting oils have the property of
may not enable them to withstand exposure even for a day. The defattening the skin. They also plug the pores of the skin and
exposed parts of the body become erythmatous accompanied form comedones. After some days of use they may contain steel
by violent itching, swelling and oedema of the face, eye - slivers, which may injure the skin and thus start dermatitis
lids, ears, neck and forearms. Teeth become black owing to affecting the forearm and thigh, small blackheads due to
the formation of mercuric sulphide. Cleanliness of the plant blocking of the sebaceous glands appear in these areas.
is important. All precautions as for a lead factory should be Prevention
taken. Exhaust ventilation with fitting overalls, aprons, rubber
gloves, and if necessary respirators as well. Additional hand Cleanliness of persons, their clothes and machines should be
washing facilities should be provided (26 - 31). ensured by the provision of adequate washing and shower
bath facilities. suitable industrial cleaners should be placed
Chromium at convenient location in the washroom. Clean rags or cotton
Chromic Acid and bichromates of sodium and potassium are waste free from silver should be provided. Time should be
used in chromium plating of metals, manufacture of explosives allowed for workers to carry out thorough cleansing, change
and for tanning of leather, characteristic chrome ulcers occur of clothes and dressing. Those who give a previous history of
on nail beds and the nasal septum. They are small, deep ulcers dermatitis should be excluded by pre placement examination.
varying in size from the head of a matchstick to the end of a Persons suffering from seborrhea, acne and excessive sweating
lead pencil. The tissues around the ulcers are heaped up and should be prohibited from employment appear, the person
are covered by crusts. They may cause perforation of the nasal should be temporarily withdrawn from the process and re -
septum. The ulcers are as rule not painful but heal very slowly employed when the skin condition clears up.
(25 - 31). Treatment
Prevention The treatment is usually by soothing lotions or cream like
Mechanical lateral exhaust ventilation should be provided for calamine. Barrier creams may help in getting the skin of the
the removal of the vapour and spray at the point of origin. The beginners slowly conditioned to the contact with cutting oils
floor of rooms containing chrome baths should be impervious, but cannot serve as a permanent protective measure for persons
maintained in good condition and flushed out daily. Suitable whose skins are excessively sensitive.
rubber gloves, aprons and other protective clothing should Benzene
be provided and maintained properly. Water taps should be
installed in workplaces, to enable the workers to wash hands This is colourless aromatic hydrocarbon with a characteristic
• 1283 •

17. pleasant smell. It is extensively used as a solvent and a starting when it combines with haemoglobin, as its affinity for the
material in the synthesis of numerous chemicals (25, 26, 32 - haemoglobin is about 300 times that of oxygen ( 25,26 ).
36). Symptoms
Acute Poisoning Acute poisoning causes a sudden onset of unconsciousness,
Clinically, acute poisoning is of three general types, depending rapidly developing cyanosis and death. Initial symptoms of
upon the severity of its anaesthetic effects on brain centers. sub acute carbon monoxide poisoning, which are more likely
Very high concentrations of benzene inhalation may result in to be encountered in industry than the acute poisoning are
unconsciousness, followed by death from respiratory failure. shortness of breath palpitation on exertion accompanied by
With somewhat lower concentrations, there may be dizziness, slight headaches which tend to increase in severity. With the
weakness, apprehension, collapse and unconsciousness. Death increased concentration of this gas in the blood, judgment
may occur from respiratory failure. becomes fogged and the affected individual may not realise his
Chronic Poisoning own danger. If the exposure continues, mental aberration is
followed by unconsciousness resulting in death from respiratory
The haemopoetic system is mostly affected but degenerative failure. Chronic poisoning shows all these symptoms coming
changes are also observed in the kidneys and heart. There on gradually and then continuing for longer periods.
is weakness, dizziness, rapid pulse, persistent headache,
malaise, loss of appetite, shortness of breath, undue fatigue, Prevention
decreased resistance to infections, and ulcers in the throat. Minimising its leakage by ensuring efficient ventilation,
Due to decrease in platelets, there is bleeding from the mucous and finally by observing the rules of personal protection can
membrane and haemorrhage in tissues. Macrocytic anaemia prevent carbon monoxide poisoning. No person should be
gives more reliable indication of the poisoning than leucopenia, allowed to work single handed in a place where there is a
especially in the early part of the disease. danger of production of this deadly gas. No workman should
Prevention enter or approach a place until the gas has been flushed out
by fresh air and a suitable breathing apparatus issued. Safety
The ventilation of the workroom should be improved by posters in common languages should be displayed at strategic
mechanical exhaust ventilation. A monthly examination of the points explaining the deadly nature of symptoms of poisoning
employees should be carried out including a complete blood and means of rescue and first aid. Workmen should be given
count, and findings recorded in a special register. There should practice drill in rescue operation, artificial respiration and
be a rotation in duties of the personnel. Worker’s showing an resuscitation. A cylinder containing a mixture of 95 percent
altered blood picture should be removed from exposure. They oxygen an 5 percent carbon dioxide with a close fitting mask,
should report for medical examination, if bleeding from the should be available at all times for immediate use.
nose, gums or other mucous membranes is noticed. Toluene,
Xylene, Cyclohexane or trichloroethylene can be used as Treatment
comparatively safer and satisfactory substitutes for benzene. The victim should be removed immediately into fresh air and
should not be made to walk even if he is conscious. The oxygen
Trichloroethylene (Trilene) and carbon dioxide mixture should be administered or oxygen
It is colourless liquid with chloroform like odour. It is largely should be administered under positive pressure if available. If
used in the metal industry as a degreaser. When the exposure is the breathing has stopped or is shallow, artificial respiration
sudden, the worker may die and the post - mortem examination must be started and continued until normal breathing returns. If
may reveal oedema of the lungs and petechial haemorrhages. the heart has stopped beating, cardiac massage and stimulants
Fatty degeneration of the liver, kidneys and heart is present if should be given. Absolute rest in bed and warmth are essential.
death is delayed. Repeated exposure affects the central nervous A close vigil should be maintained because of the tendency to
system leading to paralysis of the hypoglossal nerve, sensory relapse. Artificial respiration, administration of oxygen - CO2
fibres of the fifth nerve, second cranial nerve and polyneuritis mixture and cardiac massage should not be stopped until it is
in the limbs. Mild poisoning may cause various grades of quite certain that heartbeat can not be revived.
unconsciousness as occurred in the past in laundry workers.
Trichloroethylene should be used only in closed systems or in Hydrogen Cyanide
rooms with a downward exhaust ventilation system. Workmen It is colourless gas with a penetrating bitter almond odour,
with dry and fissured skin should not be permitted to handle Sodium and potassium cyanide baths used in the heat treatment
the chemical. Inhalation of a mixture of 95 percent carbon of steel and iron are potential health hazards (25, 26).
dioxide is of great value in the treatment of poisoning. Artificial Symptoms
respiration may be necessary ( 25,26,31,32).
Hydrogen cyanide like carbon monoxide is a chemical
Carbon - Monoxide asphyxiant and prevents the tissue from using the oxygen
It is a colorless and odourless gas formed from the incomplete carried in the blood. When inhaled in high concentration it
combustion of materials containing carbon. It is encountered caused sudden collapse and almost immediate death. In lower
in various industries such as foundries, gasworks, ovens, blast concentration symptoms are delayed; the patient complains of
furnaces and in automobile garages. It is a chemical asphyxiant. headache, dizziness, vomiting, general weakness; slow and
It forms a relatively stable compound, carboxyhaemoglobin irregular respiration and pulse is almost imperceptible. There
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