Adducts of acrylonitrile with hemoglobin in nonsmokers and in participantsin a smoking cessation program

Hemoglobin adducts have been used to assess exposure to carcinogenic compou nds in tobacco smoke. However, because of background levels in nonsmokers, most adducts that have been studied are not useful for monitoring low-level exposure. Bergmark [(1997) Chem. Res. Toxicol. 10, 78-84] showed that the level of adducts of acrylonitrile (AN) with N-terminal valine (ANVal) incre ases with increasing cigarette consumption, and the increment from 1 cigare tte/day was estimated to be 8 pmol/g of globin. The background level of ANV al in nonsmokers was not quantified (<2 pmol/g of globin). The objective of this study was to determine the background level of ANVal in hemoglobin an d to study the stability of this adduct in vivo. Globin samples previously analyzed by Bergmark from 17 nonsmokers and 2 smokers were reanalyzed in th e study presented here. Globin samples from 7 additional nonsmokers and fro m 10 participants in a smoking cessation program were also analyzed. Smokin g habits and exposure to environmental tobacco smoke (ETS) were assessed by interview. Only two of the participants completed the program. The levels of ANVal in these 2 subjects decreased after quitting and were at backgroun d level by 126 days. The time course of the decrease was compatible with re moval of stable adducts. The levels of ANVal in the nonsmokers were 0.76 +/ - 0.36 (mean +/- SD) (n = 18; reporting no exposure ETS), 1.1 +/- 0.6 (n = 3; reporting exposure to ETS), and 1.2 +/- 0.5 pmol/g of globin (n. = 3; sn uff users). Thus, the adduct level in nonsmokers corresponds to the adduct increment from about 0.1 cigarette/day. Measurements of the level of ANVal could be used to distinguish between nonsmokers and low-level smokers on an individual level, but larger groups of individuals would be required to de tect a possible contribution to the background from passive smoking.