Exposure to genotoxins present in ambient air in Bangkok, Thailand particle associated polycyclic aromatic hydrocarbons and biomarkers

Exposure to genotoxic compounds in ambient air has been studied in Bangkok, Thailand, by analysis of polycyclic aromatic hydrocarbons ŽPAHs. associated with particles and using different biomarkers of exposure. Eighty-nine male, non-smoking Royal Thai police officers were investigated. The police officers were divided into a high exposure group Žtraffic police. and low exposure Žoffice duty.. Particulate matter was collected using personal pumps Ž2 l min. and the eight carcinogenic PAHs were analysed by standard procedures. The traffic police was exposed to a 20-fold higher level of total PAHs than office police Ž74.25 ng m3 vs. 3.11; P 0.001.. A two-fold variation was observed between the different police stations. The major PAHs in all groups was benzo g,h,l pyrelene. Large inter-individual differences in biomarker levels were observed, but the level of all markers was statistically significantly higher in the traffic police group than in the office group. The level of 1-hydroxypyrene Ž1-HOP. was 0.181 0.078 Žrange 0.071 0.393. mol mol creatinine in the traffic group and 0.173 0.151 ŽP 0.044. in the office group. The bulky carcinogen DNA-adduct level, determined by P32-post-labelling, was 1.6 0.9 Žrange 0.4 4.3. adducts 108 nucleotides in the traffic group and 1.2 1.0 Ž0.2 4.9. in the office group ŽP 0.029; Mann Whitney U-test.. The serum PAH albumin adduct level was 1.76 Ž0.51 3.07. fmol adducts g albumin in the traffic group and 1.35 0.77 Ž0.11 3.45; P 0.001. in the office group. Lower biomarker levels were observed during the period when the traffic police officers were wearing a simple facemask, indicating that these masks protect against particle-associated PAHs. No statistically significant correlations were observed between biomarker levels and the level of individual PAHs or total PAH. Our data show, that people in Bangkok, who spend most of the day outside air-conditioned offices, are exposed to high levels of genotoxic PAHs. However, for people who spend their working day in offices, the exposure is similar to people living in other metropolitan areas.