[Carbon monoxide exposure in automobile garages: evaluation of mechanics]

Carbon monoxyde (CO) exposure is an occupational hazard for car mechanics. Following two cases of CO poisoning and a preliminary environmental assessment of four car dealerships, a descriptive study was initiated in 76 car dealer repair shops in the Quebec City area to evaluate CO exposure. Alveolar CO of 496 mechanics and ambient CO in 47 car dealer repair shops were measured: 44.6% of non smoker workers had an alveolar CO level greater than 27 ppm which is equivalent to a 5% level of carboxyhemoglobin (HbCO). Ambient CO was greater than 35 ppm in 42.6% of car repair shops, a level considered a risk for chronic health effects. The following measures were proposed to car dealership owners to reduce mechanics' exposure to CO: 1) Install or improve local or general ventilation systems, 2) improve the layout of the repair shops, and 3) prohibit running of car engines without proper connection to the ventilation system.