Aromatic hydrocarbons in the atmospheric environment. Part III: personal monitoring

As part of a larger study, personal sampling of the aromatic hydrocarbons b enzene, toluene, ethylbenzene and the isomeric xylenes (BTEX) was carried o ut by 55 nonsmoking volunteers for a period of 14 days. Thirty-nine persons lived in a rural area near Hannover (Germany) with hardly any traffic at a ll, while 16 persons lived in a high-traffic city street in Hannover. The p ersonal exposure level of the persons in the rural area (some commuting to Hannover) was: 2.9, 24.8, 2.4 and 7.7 mug m(-3) for benzene, toluene, ethyl benzene and the sum of xylenes, respectively, while the corresponding data for the high traffic city streets were 4.0, 22.2, 2.8 and 9.7 mug m-3 (geom etric means). Four microenvironments have been monitored which contribute t o the total exposure to BTEX, i.e. the home, the outdoor air, the workplace and the car cabin. The most important microenvironment for non-working per sons is the private home. The concentration of most BTEX in the private hom e is almost equal to the personal exposure level, demonstrating that the in door pollution in the home makes by far the highest contribution to the tot al exposure. For working people (mostly office workers), the workplace is t he second most important microenvironment contributing to the total BTEX ex posure. Taking all working persons into consideration (independent of the l ocation of their private home) the personal exposure level is higher by a f actor of 1.2-1.4 than that of the workplace (for toluene this factor is 2.2 ). As already found by others, very high BTEX concentrations may be found i n car cabins, in particular, if the engine is gasoline-driven. In the cabin of 44 cars in the rural/urban area average benzene concentrations (geometr ic mean) of 12/14 mug m(-3) and a maximum value of similar to 550 mug m(-3) were found. On average, the participating volunteers drove their car for 4 5 min day(-1) (i.e. 3% of the day). Nevertheless, the car cabin constitutes about 10% of the total benzene exposure. Refueling of the car during the 1 4-day sampling period has only a small effect on the personal exposure leve l. (C) 2001 Elsevier Science Ltd. All rights reserved.