Exhaust Fumes Danger To Garage Workers

Press, Volume CI, Issue 29765, 7 March 1962, Page 12

Exhaust Fumes Danger To Garage Workers

Provision should be made in new garages and testing stations for floor vents to carry off exhaust fumes, and some provision for removing fumes from places where engines were tested should be made in existing garages, the Dilnedin medical officer of health (Dr. J. F. Coppiestone) said in the “New Zealand Medical Journal.” Carbon monoxide was the greatest danger from the exhausts of petrol engines, said Dr. Copiplestone. It was an acute poison, which acted by affecting the oxygen-carrying mechanism of the blood. The affinity of haemoglobin for carbon monoxide was 300 times that of its affinity for oxygen, so that the monoxide was hazardous even in very small quantities. The amount of carbon monoxide in exhaust gases was higher when a vehicle was idling than when the engine was under load, and was higher in a badly-tuned engine than in' one which was correctly tuned. An idling engine could produce up to 15 per cent, carbon monoxide, yet as little as one hundredth of 1 per cent, breathed for most of a working day could cause headache and a reduction in efficiency. A concentration of one-tenth of 1 per cent, would cause dizziness In one hour, while an hour’s exposure to two-fifths of 1 per cent, could be fatal. The maximum allowable concentration for a 40-hour working week was onethousandth of 1 per cent At a testing station a test for carbon monoxide at the bench where certificates were writ-

ten out had shown a concentration of 10 times the allowable maximum.

A certain amount of carbon monoxide was produced in cigarette smoking. Although the quantity was not usually enough to cause discomfort in itself, when it was added to an intake of carbon monoxide from car exhausts the aggregate level was sufficient to cause the headaches of which. Dr. Coppiestone said, certain garage workers complained. Diesel engines did not produce a hazardous amount of carbon monoxide, but nitrogen dioxide and other oxides of nitrogen were produced and the maximum allowable concentration of nitrogen dioxide was only one-twentieth of the figure for carbon monoxide.

Nitrogen dioxide acted in an insidious fashion in that the full effects were not felt for several hours after exposure. For this reason, Dr. Coppiestone thought any move to cleanse other more speedily-acting gases, such as the aldehydes, from diesel exhausts should not be considered very favourably unless the dioxide were also removed. There seemed little risk to the public from carbon monoxide, said Dr. Coppiestone, except in special circumstances such as in tunnels. Some workers believed, however, that the oxides of nitrogen might under certain conditions contribute markedly to city air pollution problems. Hydrocarbons given off in exhausts were major contributors to smogs in some cities.