Damage to the Nervous System from Gas Poisoning *

MANY gases employed in industry, if accidentally inhaled in toxic proportions, may cause damage to the nervous system. Examples are:-carbon dioxide; the cyanides used in hardening metals; methyl bromide and chloride-employed in fumigating and refrigerating processes; cleansing agents and fat solvents such as carbon tetrachloride, ethylene chloride and amyl acetate-liquids which vapourize easily. The last two are used extensively in modern aircraft construction and possess anmsthetic properties. They are potentially dangerous when sprayed by operators working in a confined space, as in sealing off the interior of a main-plane to adapt it as a fuel storage tank (Smiley, 1954). Other aliphatic compounds include carbon disulphide, a fat solvent used in the manufacture of rayons which is reported to have caused sudden visual failure due to acute retrobulbar neuritis and polyneuritis with a Korsakow type of mental picture. Recently a case of hydrogen sulphide poisoning in a sewer worker was reported (Hurwitz andl 'T'aylor, 1954), and another writer draws attention to the danger of anoxia from men entering sewers without preliminary testing of the oxygen content of their atmospheres (La ucet, 1954). 'T'he character of the nearby soil and changes in barometric pressure may influence the rate of absorption of oxygen so that the content of a sewer may be as low as 6 per cent. Similar risks may be encountered in ship repairing, where men are required to open up and inspect the interior of deep tanks. 'T'he bitumastic paint, with which they may be painted, facilitates the absorption of oxygen, or water may have gained access so that rusting occurs. One would think some considerable time would have to elapse for a significant reduction of oxygen to occur, but, recently, a fatal accident from asphyxia resulted when two men entered a deep tank in xvhich pig iron had been stored as ballast, the tank only having been sealed some four weeks previously. Analysis of the gas in the compartment revealed traces of carbon monoxide and unsaturated hydrocarbons, 96.2 per cent. of nitrogen, and only 3.8 per cent. of oxygen (Fletcher, 1954). However, of gases the most widely accepted as an industrial hazard is carbon monoxide. Some years ago, over a period, I investigated all the cases of acute coal-gas poisoning admitted to the Royal XVictoria Hospital, Belfast (Allison, 1950). Many of them had been suicidal attempts, but a number were accidental, and such cases occur from time to time. …