Exposure to volatile organic compounds in the passenger compartment of automobiles during periods of normal and malfunctioning operation.

In-vehicle exposures to selected gasoline-derived volatile organic compounds (VOCs) and formaldehyde were examined on 113 commutes through suburban New Jersey and on 33 New Jersey/New York commutes using measurements taken in two vehicles driven in tandem during 1991-1992. Overall median exposures to VOCs were lowest on the suburban commute, slightly higher on the New Jersey Turnpike, and highest in transit through the Lincoln Tunnel. Median in-vehicle concentrations of benzene, ethylbenzene, m- and p-xylene, and o-xylene were 14 microg/m3, 6.8 microg/m3, 36 microg/m3, and 15 microg/m3, respectively. For a motorist who commutes 93.2 min daily (6.5% of the day), this corresponds to 12.1%, 10.8%, 14.9%, and 14.7% of the total daily exposures to these compounds. One vehicle, with a carbureted engine, developed malfunctions which caused gasoline emissions within the engine compartment during driving. Resultant gasoline-derived VOC concentrations in this vehicle measured much higher than in the properly maintained, fuel-injected vehicle, particularly for the low ventilation extreme. The highest in-vehicle benzene concentration measured during these malfunctions was 45.2 microg/m3. The air concentration in the vehicle driven in tandem was a factor of 25 less (1.8 microg/m3). A motorist who drives for the average daily period of 93.2 min/day in this malfunctioning automobile will have a benzene exposure of 2.8 (microg/m3)day, compared to 0.1 (microg/m3)day in the properly functioning vehicle.