Benzo(a)pyrene diolepoxide-haemoglobin and albumin adducts at low levels of benzo(a)pyrene exposure

A biomonitoring study was conducted to simultaneously measure individual be nzo(a) pyrene (BaP) exposure in 50 office employees, not occupationally exp osed to polycyclic aromatic hydrocarbons (PAH), using personal samplers and the formation of (+) r-7, t-8-dihyroxy-t-9, t-10-epoxy-7,8,9,10-tetrahydro benzo(a) pyrene (BPDE) adducts to haemoglobin (BPDE-Hb) and serum albumin ( BPDE-SA). The population enrolled was exposed to an average of 0.58 +/- 0.4 6 ng BaP m(-3) (mean +/- SD). The concentration of BaP collected from smoke rs' samples was double that from non-smokers (P = 0.007). BPDE adducts to H b and SA were quantified as BaP tetrols released from hydrolysis of macromo lecules and measured by high-resolution gas chromatography-negative ion che mical ionization-mass spectrometry. BPDE-Hb adducts were detected in 16% of the population and BPDE-SA adducts in 28%. Smoking did not affect adduct f ormation. When BaP personal monitoring data were used as the criterion of e xposure, no correlation was found with the presence and the levels of BPDE- Hb and BPDE-SA adducts. Undetected sources of PAH, such as the diet, might markedly alter the exposure profile depicted by individual air sampling and affect the frequency and levels of protein biomarkers. This is the first c omparative analysis of BPDE-Hb and BPDE-SA adducts, providing reference val ues for these biomarkers in a general urban population. However it is diffi cult to establish which biomarkers would be the more relevant in assessing low BaP exposure, due to undetectable factors such as dietary PAHs, that mi ght have influenced the results to some degree.