URINARY-EXCRETION OF 1-HYDROXYPYRENE AS A MARKER FOR EXPOSURE TO URBAN AIR LEVELS OF POLYCYCLIC AROMATIC-HYDROCARBONS

A cross-sectional study was conducted among 94 traffic police officers from the Municipality Police of Genoa, Italy, exposed to airborne pol lutants and 52 referent subjects exposed to indoor air pollution level s to investigate the relationships between exposure to ambient air pol ycyclic aromatic hydrocarbons (PAHs) and urinary excretion of l-hydrox ypyrene (1-OH-P). The effects of smoking, lifestyle factors such as ex posure to ETS, and diet, along with the role played by the cytochrome P4501A1 (CYP1A1), and glutathione S-transferase M1 and theta metabolic susceptibility gene polymorphisms were examined. The geometric mean o f benzo(a)pyrene air measurements (an index compound of PAH levels) wa s 70 times higher in traffic police officers (3.67 ng/m(3)) than in re ferents (0.05 ng/m(3)). The urinary concentration of 1-OH-P was clearl y associated with cigarette smoking and, to a lesser extent, with expo sure to ETS and particulate PAH pollution. No association was detected between 1-OH-P excretion and diet. Women exhibited a higher excretion level than did men, and an apparent effect of age was due to differen ces in cigarette smoking habits. Exposure to PAHs resulted in higher l evels of 1-OH-P excretion in all groups except heavy smokers. Overall, no significant role of any metabolic polymorphism was detected. Howev er, stratification of study subjects according to their smoking habits revealed higher levels of excretion of 1-OH-P in subjects smoking les s than or equal to 15 cigarettes/day carrying the CYP1A1 polymorphism. No such effect was seen either with nonsmokers or with people smoking more than 15 cigarettes/day. These findings are suggestive of a gene- environment interaction. in which subjects with the CYP1A1 polymorphis m. relative to subjects without it, have higher levels of 1-OH-P in th eir urine at low doses of exposure to PAHs.