Read this essay to learn about the two major industrial problems that affect human health. The industrial problems are: 1. Industrial Metal Poisoning 2. Poisoning by Coal Tar Derivatives.
Essay # 1. Industrial Metal Poisoning:
i. Lead:
Two types of compounds exist:
(a) Inorganic and
(b) Organic.
With inorganic compound, poisoning symptoms are more mental. Lead is soft bluish grey metal, heavy, malleable and non-corrodible. More than 200 industries deal with lead.
Hazardous Occupations:
(1) Mining and smelting of lead ores,
(2) Plumbing,
(3) Ship breaking,
(4) Painters using white or red lead,
(5) Vitreous enameling,
(6) Colour manufacturing,
(7) Electric accumulator,
(8) Dry battery industry.
Metabolism:
In the above occupations, lead and its compounds enter the body via the air passages by inhalation of dust and fumes, and also by ingestion and absorption through skin. It is taken by the blood and deposited in the bones with calcium.
Signs and Symptoms of Lead Poisoning:
a. Lead colic.
b. Lead encephalopathy.
c. Chronic lead encephalopathy.
d. Other symptoms and signs.
e. Organic lead compound.
Preventive Measures:
Specially prevention of dust fumes and periodic check up including urine excretion of lead, specific treatment with calcium I. V., vit. D. In serious cases e.g. encephalopathy, immediate binding of free lead with calcium and string and afterwards slow deleading from depots are practiced.
BAL (British Anti-Lewisite 2: 3 dimer captopropenol) and EDTA are specific treatments, over and above the symptomatic treatment in serious cases.
ii. Mercury:
Exposure Hazards:
(1) Scientific instrument laboratories—electrical current meters.
(2) Mirror industry.
(3) Gilding.
(4) Photoengraving.
(5) Manufacture of fur hats.
(6) Manufacture of Explosives:
a. Chronic Hg poisoning
b. Sub-acute and acute poisoning
c. Organic compounds of mercury are used as fungicide.
Prevention:
Substitution by silver in mirror industry, for gilding, electroplating, ventilation, good house-keeping, dental supervision of workers are important. Using workroom with smooth asphalt floor and working tables with enameled iron tops and temperature below 60° F (15.5°C) help to reduce the danger. Specific treatment in cases of poisoning.
iii. Arsenic:
Arsenic is used as pigment and compounds like sodium arsenite, lead di-arsenite, Scheele’s green or cupric arsenite are used in:
(1) Colouring of wall-paper.
(2) Sweetmeat wrappers.
(3) Toys, artificial leaves and flowers.
(4) Textile colouring.
(5) Rubber colouring.
(6) Distemper.
(7) Oil paint.
(8) Lithographer’s paint.
(9) Coloured soaps.
(10) Sweetmeats.
Preventive Measures:
Dust suppression, exhaust ventilation, protective clothing’s, respirators, mask and overalls and personal hygiene are important. BAL and EDTA are used as specific treatment.
iv. Phosphorus:
Formerly when yellow phosphorus was used in match industry poisoning was common, giving rise to the classical clinical condition ‘Phossy jaw’ with sinuses, ulceration and sequestrum formation of lower jaw. The red phosphorus now used does not give rise to the above complication.
Compounds of phosphorus-phosphates are very common in many industries specially:
(1) Brewing.
(2) Food processing.
(3) Baking powder.
(4) Manufacture of cellulose.
(5) Dyes.
(6) Soaps.
(7) Fertilizers.
(8) Detergent.
Toxicity:
Organophosphorus compounds inhibit action of pseudo cholinesterase with clinical picture of polyneuritis giving rise to flaccid paralysis and foot and wrist drop.
v. Manganese:
Hazards of poisoning occur in the following industries:
(1) Mining
(2) Crushing
(3) Sieving
(4) Loading
(5) Processing of ore
(6) Manufacture of ferromanganese and other alloys
(7) Dry batteries
(8) Potteries
(9) Fireworks and
(10) Uses of manganese and permanganate compounds.
Like many heavy metal poisonings when absorption of manganese is more the workers develop neurological, nervous and respiratory problems.
vi. Beryllium:
Beryllium is used for alloys with other metals as it makes the alloy hard, corrosion-resistant, non- sparking, non-magnetic and elastic. Fluorescent lighting tubes are coated inside with phosphorescent compounds of beryllium. It is irritant to skin and causes dermatitis.
Irritation of respiratory passages and lung parenchyma may cause mild bronchitis, tracheitis or, in severe cases, beryllium pneumonitis. Chronic beryllium poisoning may give rise to fibrotic and nodular condition of the lung with typical X-ray showing increased linear markings granular or ground-glass appearance.
vii. Chromium:
Chromium forms a number of coloured compounds. The metal is silver-white and hard. It is used in making alloys with other metals, manufacture of stainless steel, restless steel and some of its compounds as colours in a number of industries. Chromium plating is done by the process of electrolysis by putting of metal article as an electric pole in a tube containing a solution of 50% chromic acid.
Reddish brown fumes of chromic acid are evolved in this process which, when inhaled, cause irritation of respiratory passages and the solution settling on the skin gives rise to dermatitis. Chrome ulceration, circular and punched out, begins in abrasions at the root of finger nails, knuckles of hand or dorsum of foot. It may also be found on eyelids and nostril edge by settling of dust or fumes.
Nasal septal perforation is quite common in persons working in chromium electroplating. Differential diagnosis:
(a) Syphilis,
(b) Leprosy,
(c) Glanders,
(d) Arsenic dust,
(e) Radioactive exposure,
(f) Certain cancers,
(g) Trauma,
(h) Mercury fulminates and also rarely occurs with
(i) Nitrous acid,
(j) Chlorine fumes.
viii. Radioactive Metals:
A number of radioactive metals radioactive substances and compounds and radioactive rays are used nowadays and in future these will increase rapidly making this a very important subject.
Exposure Hazards:
(1) X-rays used in diagnosis and therapy.
(2) Use of radium.
(3) Industrial X-ray and Gamma Radiography.
(4) Nuclear energy establishments and research.
(5) Radioactive ore mining, processing etc.
(6) Radioactive isotopes—production and utilisation.
(7) Specially for defence.
(8) Radioactive dust, fumes, vapour and wastes from nuclear power stations.
(9) Radiation from natural sources e.g. sun rays and in the atmospheric radiation belts in space.
Essay # 2. Poisoning by Coal Tar Derivatives:
i. Benzene:
It is a volatile colourless liquid with distinctive odour, the basic chemical from which all coal tar chemicals and dyes are made. It is solvent for rubber, guttapercha, resin, gums etc. used for extraction of alkaloids and oils and in manufacture of varnishing paints, dyes, inks and as cleaning and degreasing agent.
It is also used in linoleum and celluloid manufacture, quick drying paints, lacquers, rubber, cement etc. Route of entry by inhalation or through skin. Ingestion very rare.
ii. Aniline:
Anilism is a term used for acute or chronic poisoning by benzene, phenol or their amino derivatives, specially ‘Aniline’. Aniline is a colourless oily liquid with aromatic odour. It is used in the manufacture of dyes, perfumes, pharmaceutical products, photographic chemicals, textile dying, printing, varnishing, rubber processing etc. Symptoms are referred to blood, heart and C.N. system.
Cyanosis of intense blue colour due’ to methaemoglobinemia, headache, fatigue, loss of appetite, unsteady gait, neuritis, are common. Acute symptoms of vertigo, convulsions and coma may occur. Chronic symptoms are more of C.N. system. Punctuate basophilia is an early sign of aniline poisoning. The dye is excreted in urine and may cause bladder cancer.
iii. Trinitrotoluidine:
It is a solid pale yellow crystal and is used for the manufacture of explosives for dynamites, bombs used in military operations, mines, rock and tunnel excavations, etc. During the world war many persons were working in military factories with T.N.T. It is absorbed through skin, inhalation of dust and by ingestion from soiled hands common.
iv. Carbon Tetrachloride (CCI4):
It is a colourless liquid with sweetish smell. It is widely used in industries for its solvent properties e.g., in rubber, chemical and paint industry and for extraction of fats. It is also used as cleaning agent and degreaser in metal parts cleaning, hair shampoo and soap manufacture, dry cleaning, also in manufacture of Freon, fire extinguishers, grain fumigation etc.
Toxicity:
It is a dangerous poison affecting liver and kidneys and C.N. system. Acute poisoning by inhalation of vapours may give rise to giddiness, staggering and vomiting; in severe cases unconsciousness and death.
Chronic poisoning may result in damage to the liver and kidneys and toxic amblyopia. Loss of appetite, headache, disturbances of stomach, enlarged liver and jaundice. Scanty urine, albumin and casts in urine, oedema, raised blood urea are common symptoms of kidney damage.
Pneumoconiosis:
Pneumoconiosis is a general name given to the effects produced in the lungs by inhalation of dusts. The legal term pneumoconiosis for workmen’s compensation etc. is defined as the fibrosis of the lungs due to inhalation of silica, asbestos or other dusts. Some people have used this word more commonly denoting fibrosis due to the mineral dusts of size range of 0.5 to 3.0 micron.
a. Silicosis:
Silicosis:
Is a fibrotic condition of the lungs due to inhalation of silicon dioxide (SiO2), Silica dust. It is one of the oldest known prevalent diseases, particularly among the miner who are exposed to rock cutting or blasting or drilling etc., and was formerly named ‘Miner’s Phthisis’ Rock T.B., Stone mason’s disease etc.
Hazards:
Industries, trades and occupations, where workers are exposed to silica dust are: Gold, Mica, Coal, Asbestos, Iron ore, Quarrying of stone. Slate, Quartz etc. crushing and grinding of stone, dressing building stone or mill stone, grinding of metals on sandstone wheel, granite industry, pottery industry, iron and steel foundries, refractory and flint products, sand blasting, glass industry etc. wherever stone or silica dust is produced.
Prevention:
Exist suppression measures in all different ways including wet processes, better ventilation, local exhaust, wet drilling, foam drilling etc. are used. Replacement of silica material with harmless material like limestone (CaCO3) if possible, repeated medical and X-ray check ups.
b. Coal Miners’ Pneumoconiosis (Anthracosis):
The coal miners lungs are often laden with jet- black coal dust causing a condition called Anthracosis, commonly found at autopsy in healthy miners. But fibrotic lung condition anthracosilicosis is a disabling disease with bad prognosis. This condition, though similar to silicosis, has a number of differences. Coal dust is less harmful than silica dust but may also be complicated with tuberculosis.
It is a more chronic disease ultimately forming massive fibrosis of the lungs. Focal emphysema is a characteristic feature and surrounds the nodules to give a peculiar X-ray of nodulation and emphysema over-lapping. Breathlessness, cyanosis and clubbing are more common than silicosis and congestive cardiac failure is the common end.
Clinical:
Generally more than ten years’ work causes this, more commonly 15-20 years. Breathlessness, cough, melanoptysis, fever, haemoptysis, barrel-shaped chest, clubbing and cyanosis are common symptoms. Dullness and/ or hyper resonance coarse rales and rhonchi are common. Ultimately death results from tuberculosis or congestive cardiac failure.
Preventive Measures:
In Pneumoconiosis, the preventive measures are aimed at prevention of dust by changing methods of work in wet cutting, water sprays, local exhaust and general ventilation etc. repeated medical check-ups and X-rays and alternating employment and withdrawal at the first signs of the disease are recommended. A number of cases of coal miner’s pneumoconiosis are reported from coal miners in India.
c. Asbestosis:
Asbestos is a fibrous mineral silicate of magnesium and iron found in many countries of the world. It is heat proof and non-conductor of electricity. It is mixed with cement, rubber, resin, plastic for heat and electric insulation, roofing, woven into cloth for fire-fighting suits, theatre safety curtains, boiler mattresses.
Hazards in mining, disintegrating, carding, spinning and weaving of asbestos. In mining, asbestos is embedded in rock and hence silicosis is a risk also. There are few mines and factories of asbestos in India though cases are not yet reported.
d. Byssinosis:
it is a disease of lungs first described by Thackrah of Leeds, due to dust in cotton textile mills most commonly found in cotton cleaning mixing and carding of cotton and, therefore, most common in blow-room and cardings, department workers of textile mills. This is an allergic phenomenon due to dust in these departments though whether it is due to cotton dust or to bacterial contaminants is disputed. Fibrosis is not a predominant finding as it is allergic in nature.
(1) Mill Fever:
This is seen in a number of people when first exposed to cotton dust and results in a cough, chill, fever, nausea and vomiting. It is sometimes seen in a mild form in visitors to cotton mills.
(2) Weaver’s Cough:
This is found only among those who work in the weaving sheds and is due to moulds which may grow on the farm. The symptoms are cough, restricted feeling in the chest, and rise in temperature.
(3) Byssinosis:
This is a chronic disease, resembling asthma, arising in certain workers following long exposure to cotton dust.
e. Bagassosis:
It is an allergic disease of the lungs caused by sensitisation to bagasse dust. Bagasse is the dry fibrous waste of sugar cane after the juice is extracted from the cane. Just like byssinosis whether this disease is due to bagasse dust or the bacterial, fungal or other contaminant of the dust is not certain.
The bagasse is used to prepare soft boards, fibre boards, rough paper etc. and India having a very large cultivation of sugar cane and large number of sugar factories this waste product is available in plenty and is utilised by some factories. In future such utilisation will increase.
Preventive Measures:
Dust suppression measures in general and particular should be employed, personal protective equipment may be used. Pre-employment examination and periodic check-ups are necessary.
f. Farmer’s Lung:
It is due to the inhalation of mouldy hay or grain dust. When moisture contains more than 30%, bacterial fungi grow rapidly. Micropolyspora faeni is the main cause of farmer’s lung. The acute illness is characterised by general and respiratory symptoms and signs. Repeated attacks cause pulmonary fibrosis and cor pulmonale.