Document 6b0qGgE4Rm4OayMVOp9YJBQE3

v American Society of Heating and Ventilating Engineers Guide is due to the fact that the combining power of carbon monoxide win. ' haemoglobin of the red blood: corpuscles is about 300 times greater that of oxygen. Since the resulting stable combination destroy ^ po.wer of the haemoglobin to.unite with oxygen in the lungs and to su ^ it to the tissues, the effects are due to lack of oxygen, and the sytnnt* are those of anoxemia, namely, dizziness, headaches, sleepiness, fati and, in extreme cases, paralysis and death. The dangerous saturaH^ level of the blood with carbon monoxide is about 50 per cent. Even00 little as 0.07. per cent in the air will render, in half an hour, one quarte ^ the red corpuscles incapable of uniting with oxygen. One to two na per 10,000 parts of air is set as a safe limit of pollution which may k! breathed for a long time without producing perceptible symptoms] Silicosis Silicosis is a chronic disease of the lungs which results from the local physio-chemical action of hydrated silica Upon the pulmonary tissue, causing progressive lymphatic fibrosis, and rendering the tissue susce tible to tuberculosis. The disease is slow in evolution, requiring usuallya 1 number of years of exposure. It occurs principally among granite! workers, sand blasters, metal miners, metal polishers, potters, and mill. J stone workers. 1 Lead Poisoning i Lead poisoning is the most insidious and most common of all industrial s' diseases.. It occurs principally among lead workers and smelters, lead ' miners,, potters, painters, typesetters, stereotypers, plumbers, and. workers with glass, gold and silver.. Lead,, in practically all forms, is a( cumulative poison which is absorbed by way of the blood stream, chiefly from, the respiratory tract, but also from, the digestive tract and from the skin. The effect may be either an acute or chronic poisoning.. The principal symptoms are colic, constipation, anemia, headache, anorexia, a bluish line along the edges of'the gums, rheumatic pains, and, in extreme conditions, paralysis, blindness, insanity,'and death. . It has been found6 that 2 mg per day is the smallest dose, by inhalation, which in the course of years may result in lead poisoning. Regular inhalation during the usual working hours of air containing less than 0.2 nig of lead per cubic meter does not seem to produce serious lead poisoning in individuals of representative industrial groups7. Prevention The prevention of industrial hazards from dusts and poisonous gases is largely a ventilation problem consisting of keeping the impurities in air down to a safe concentration. As yet there are no generally accepted standards on which to base the design of the ventilation equipment. Approximate data on the toxicity of various gases and fumes met with in industrial establishments are given in Table 1. Column 5, giving the maximum allowable concentrations for prolonged exposures, was com piled from experiments in which most exposures lasted not more than a Lead Poisoning, by Thomas Morrison Legge (Journal Royal Society Arts, 1929. Vol. 77, p. 1023). rWhat is a Dangerous Quantity of Lead Dust in Air, by C. M. 'Sails (Industrial Hygiene Bulletin, New York State Department of Labor, 1925). 262 Chapter 15--Air Pollution it is reasonable to assume that over more prolonged exposures ^ppfp^`^ntrat;0ns would cause pernicious effects. is'known concerning the physiological and pathological effects - bV; various types and concentrations of atmospheric pollutants. jSffiHLLscnce of an accepted standard for safe breathing, and because of cuniulative effects of certain kinds of air contaminants, the ^' rocedure *s the periodic medical examination of individuals, and the bestpiy0 T ble 1. Toxicity of Gases and Fumes in Parts per 10.000 Parts of Air3 * os Gas Cafbod monoxide...... -...... Carbon dioxide...-.............. Hydrocyanic acid............... Ammonia--.......... Hydrochloric acid gas.-----1 Chlorine--..... ............. Hydrofluoric acid gas....... Sulphur dioxide.................. Hydrogen sulphide............. Carbon bisulphide............. Phosphene........... ............... Arsine................ ................... Phosgene........... .................. Nitrous fumes--............... Benzene--...... -- Toluene and xylene. Aniline-.......... Nitrobenzene. Petrol-----------Carbon tetrachloride Chloroform--------Tetrachlorethane Trichlorethylene. Methyl chloride- Methyl bromide. Lead vapor____ ' ._____________________________ I|- Original data compiled by Y. Henderson and H. Haggard! (See Noxious Gases, 1927.) Data revised by T. M. Legge. (See Lessons Learned from Industrial Gases and Fumes, Institute of Chemistry of Great Britain and Ireland. London, 1930.) routine measurement and study of the concentration and the physical and chemical characteristics of the dusts to which those individuals are exposed. ABATEMENT OF SMOKE AND AIR POLLUTION Successful abatement of atmospheric pollution requires the combined efforts of the combustion engineer, the public health officer, and the public itself. The complete electrification of industry and railroads, and the separation of industrial and residential communities would aid materially in the effective solution of the problem. In the large cities where the nuisance from smoke,.dust and cinders is 263