phosphorus-radioisotopes and 1-hydroxypyrene

The levels of benzo[a]pyrene were monitored for blood DNA-benzo[a]pyrene adducts in 17 workers from a plant producing carbon electrodes, with high exposure to benzo[a]pyrene (575-902-1149 ng m(-3)). Two different techniques, a 32P-postlabelling method and a competitive immunoassay using polyclonal antibodies obtained from rabbits immunised with DNA modified by benzo[a]pyrene-trans-7,8-dihydrodiol-9,10-epoxide were used. For each worker, urinary 1-hydroxypyrene, a potential indicator of exposure to polycyclic aromatic hydrocarbons, was measured. The effect of tobacco by urinary cotinine measurement was also considered. The postlabelling and immunoassay detection limits for DNA-benzo[a]pyrene adducts were respectively 0.15 and 10 fmol 50 microg(-1) of DNA. The results obtained by the two methods demonstrated a good detection of DNA-benzo[a]pyrene adducts, but no direct relationship between the quantity of adducts and the concentration of benzo[a]pyrene in air-borne was noted in the studied plant. The levels of DNA-benzo[a]pyrene adducts obtained by immunoassay were significantly higher than those obtained by the 32P-postlabelling (P < 0.001). For several workers, variations due to professional or non professional factors must be taken into account in interpreting the results. In conclusion, the two methods used proved very efficient in determining DNA-benzo[a]pyrene adducts, and may be useful in monitoring human exposure to known and previously unidentified environmental genotoxic agents.

Topics: Adult; Benzo(a)pyrene; Cotinine; Cross Reactions; DNA Adducts; Electrodes; Environmental Monitoring; Graphite; Humans; Immunoassay; Leukocytes; Male; Middle Aged; Occupational Exposure; Occupational Health; Phosphorus Radioisotopes; Pyrenes; Smoking

Sensitivity, specificity and correlations among several biomarkers for monitoring occupational exposure to complex mixtures of genotoxic agents were assessed in occupational environments in Hungarian study populations. The studies have been focused on DNA adduct formation, urinary metabolites, mutations and micronuclei induced by exposures to complex organic mixtures. In two Hungarian aluminium plants, increased DNA adduct and 1-hydroxypyrene (1-OH-PY) levels were observed in workers as compared to controls. However, no association between the biomarker levels was evident on an individual basis. In Hungarian garage mechanics, DNA adduct determinations did not show increased genotoxic exposure as compared to the controls. However, ambient air measurements, significantly enhanced 1-OH-PY levels, and slightly enhanced frequency of micronuclei indicated increased polycyclic aromatic hydrocarbon (PAH) exposure in the garages, as compared to the general environment. In a Hungarian vulcanizing plant, DNA adduct determinations and 1-OH-PY did not show significantly elevated exposure levels as compared to controls. The glycophorin A (GPA) somatic mutation assay was also negative for this occupational exposure. The results support previous observations of a lack of correlation between DNA adducts detectable by 32P-postlabelling and those measured by the PAH-DNA immunoassay in the same DNA sample. These studies also demonstrate a lack of close correlation between levels of DNA adducts and urinary 1-OH-PY in the same individual.

Topics: Air Pollutants, Occupational; Aluminum; Biomarkers; Chemical Industry; DNA Adducts; DNA Damage; Environmental Monitoring; Female; Glycophorins; Humans; Imidazoles; Longitudinal Studies; Lymphocytes; Male; Metallurgy; Micronucleus Tests; Occupational Exposure; Phosphorus Radioisotopes; Pyrenes; Rubber; Sensitivity and Specificity; Vehicle Emissions

Coke oven workers are often heavily exposed to polynuclear aromatic hydrocarbons (PAHs); this exposure has been associated with higher cancer rates among these workers. We assessed the exposure of cokery workers in an oil shale processing plant. Personal hygienic monitoring, measurement of urinary 1-hydroxypyrene (1-OHP), and analysis of PAH-DNA adducts in white blood cells (WBCs) were performed. The 32P-postlabeling method was used for adduct measurement. The mean adduct value, 1.6 adducts per 10(8) nucleotides, did not differ significantly from the control value (P = 0.098). Smokers had significantly higher adduct levels than non-smoking workers (P = 0.002). 1-OHP levels measured in post-shift samples correlated with DNA adducts found in white blood cells (WBCs). We conclude that hygienic monitoring and measurement of urinary metabolites are essential background exposure data when the biologically effective dose of chemical carcinogens is assessed.

Topics: Analysis of Variance; Biomarkers; Chromatography, High Pressure Liquid; Coke; DNA Adducts; Environmental Monitoring; Estonia; Humans; Leukocytes; Linear Models; Mutagens; Occupational Exposure; Phosphorus Radioisotopes; Polycyclic Aromatic Hydrocarbons; Pyrenes; Smoking; Statistics, Nonparametric

The 32P-postlabelling assay is one of the most sensitive methods for detection of DNA adducts induced by exposure to genotoxic chemicals. Under optimal conditions, detection limits of one adduct per 10(9)-10(10) nucleotides have been reported. This sensitivity now allows monitoring of occupational and even environmental exposure of humans to certain classes of chemicals, mainly polycyclic aromatic hydrocarbons (PAH). Despite its widespread use, 3P-postlabelling is still not a standardized method. Rigorous interlaboratory comparisons are scarce, and those that have been undertaken often show rather different results, both in relative and in absolute values, for the amounts of DNA adducts in the same samples. Furthermore, the optimization of many steps in the procedure has still not been given adequate attention. This paper deals with some technical aspects of detection of PAH-DNA adducts by 32P-postlabelling, in particular with assay calibration and adduct quantification. For this purpose, benzo[a]pyrene (BP)-modified DNA standards were prepared, the adduct contents of which were determined by use of an independent fluorometric method, viz. synchronous fluorescence spectrophotometry (SFS). These BP-DNA standards are processed along with the test samples throughout the entire 32P-postlabelling procedure, from the enzymic digestion up to and including the determination of radioactivity in adduct spots on the chromatogram. As such, these reference samples can be considered as external standards for inter-assay calibration. This method for adduct quantification was compared with the commonly used relative adduct labelling (RAL) and comparative dAMP labelling, which appeared to give rise to an underestimation of adduct levels. The method was applied in a biomonitoring study among workers in a carbon-electrode manufacturing plant, exposed to PAH. Although DNA adduct levels in peripheral blood lymphocytes of exposed workers, as determined by 32P-postlabelling, were not significantly different from those of controls, a significant difference was seen when smokers and non-smokers were compared.

Topics: 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; Animals; Calibration; DNA Adducts; Environmental Monitoring; Humans; Lymphocytes; Occupational Exposure; Phosphorus Radioisotopes; Polycyclic Aromatic Hydrocarbons; Pyrenes; Rats; Reference Standards; Single-Strand Specific DNA and RNA Endonucleases; Smoking

Diesel exhaust-exposed workers have been shown to have an increased risk of lung cancer. A battery of biomarkers were evaluated for their ability to assess differences in exposure to genotoxic compounds in bus garage workers and mechanics and controls. Lymphocyte DNA adducts were analyzed using the 32P-postlabelling method with butanol and P1 enrichment procedures. Hydroxyethylvaline (HOEtVal) adducts in hemoglobin were measured by gas chromatography-mass spectrometry (GC-MS) and 1-hydroxypyrene (HPU) in urine determined using HPLC analysis. The exposed workers had significantly higher levels of all three biomarkers compared to the controls. Total DNA adduct levels were 0.84 fmol/micrograms DNA vs 0.26 in controls (butanol) and 0.65 fmol/micrograms DNA vs. 0.08 (P1 nuclease). Median HOEtVal adduct level in exposed workers was 33.3 pmol/g hemoglobin vs. 22.1 in controls. HOEtVal adducts correlated with HPU but not with DNA adducts. The levels of HPU in urine were 0.11 micromol/mol creatinine compared to 0.05 in controls. All three assays applied were sensitive enough to evaluate a low level of exposure to environmental pollutants, with postlabelling and GC-MS as the most sensitive assays. The study indicated that skin absorption of polycyclic aromatic hydrocarbons (PAH) might be an important factor to consider when studying PAH exposure from air pollution sources.

Topics: Adult; Air Pollutants, Occupational; Autoradiography; Biological Assay; Biomarkers; Cross-Sectional Studies; DNA Adducts; Environmental Monitoring; Hemoglobins; Humans; Lymphocytes; Male; Middle Aged; Mutagens; Occupational Exposure; Phosphorus Radioisotopes; Pyrenes; Vehicle Emissions