BIOMONITORING OF DIESEL EXHAUST-EXPOSED WORKERS - DNA AND HEMOGLOBIN ADDUCTS AND URINARY 1-HYDROXYPYRENE AS MARKERS OF EXPOSURE

Diesel exhaust-exposed workers have been shown to have an increased ri sk of lung cancer, A battery of biomarkers were evaluated for their ab ility to assess differences in exposure to genotoxic compounds in bus garage workers and mechanics and controls, Lymphocyte DNA adducts were analyzed using the P-32-postlabelling method with butanol and P1 enri chment procedures. Hydroxyethylvaline (HOEtVal) adducts in hemoglobin were measured by gas chromatography-mass spectrometry (GC-MS) and 1-hy droxypyrene (HPU) in urine determined using HPLC analysis. The exposed workers had significantly higher levels of all three biomarkers compa red to the controls. Total DNA adduct levels were 0.84 fmol/mu g DNA v s, 0.26 in controls (butanol) and 0.65 fmol/mu g DNA vs. 0.08 (Pi nucl ease). Median HOEtVal adduct level in exposed workers was 33.3 pmol/g hemoglobin vs. 22.1 in controls. HOEtVal adducts correlated with HPU b ut not with DNA adducts, The levels of HPU in urine were 0.11 mu mol/m ol creatinine compared to 0.05 in controls. All three assays applied w ere sensitive enough to evaluate a low level of exposure to environmen tal pollutants, with postlabelling and GC-MS as the most sensitive ass ays. The study indicated that skin absorption of polycyclic aromatic h ydrocarbons (PAH) might be an important factor to consider when studyi ng PAH exposure from air pollution sources.