Measurement and modeling of exposure to selected air toxics for health effects studies and verification by biomarkers.

摘要: The overall aim of our investigation was to quantify the magnitude and range individual personal exposures a variety air toxics develop models for exposure prediction on basis time-activity diaries. specific research goals were (1) use monitoring non-smokers at residential locations non-traffic sources assess daily toxics, especially volatile organic compounds (VOCs) including 1,3-butadiene particulate polycyclic aromatic hydrocarbons (PAHs); (2) determine microenvironmental concentrations same taking account spatial temporal variations hot spots; (3) optimize model using concentration data diaries compare modeled with independently estimated from data; (4) relationships urinary biomarkers environmental corresponding toxic. Personal measurements made an actively pumped sampler enclosed in briefcase. Five 24-hour integrated samples collected 100 volunteers patterns analysis VOCs ambient air. One PAH sample by each subject concurrently 24 hours sampling VOCs. During period when being measured, workplace home measured simultaneously, as seasonal levels other microenvironments that subjects visit during their activities, street microenvironments, transport indoor environments, environments. Information about subjects' lifestyles activities recorded means questionnaires activity tubes packed adsorbent resins Tenax GR Carbotrap, separate collection Carbopack B Carbosieve S-III. After sampling, analyzed thermal desorber interfaced gas chromatograph-mass spectrometer (GC-MS). Particle-phase PAHs onto quartz-fiber filter extracted solvent, purified, concentrated before GC-MS. Urinary liquid chromatography-tandem mass spectrometry (LC-MS-MS). Both this study are lower than those majority earlier published work, which is consistent reported application abatement measures control emissions. clearly demonstrate influence traffic meteorologic conditions leading higher winter peak-traffic hours. effect also observed where add effects previously identified outdoor sources. variability mainly reflects engaged five-day sampling. A number generic factors have been VOCs, such presence integral garage (attached home), tobacco smoke (ETS), solvents, commuting. In case medium- high-molecular-weight PAHs, ETS important contributions exposure. generally exceed concentrations, turn concentrations. microenvironment dominant contributor However, particularly high exposures, within play major role determining Correlation principal components (PCA) performed identify groups share common sources, chemistry, or patterns. We used these methods four main makeup exposures: fossil fuel combustion, exposure, consumer products. Concurrent selected total 500 urine collected, one day after five days briefcases carried collection. From samples, be ETS-related biomarkers. Results showed correlated strongly gas-phase markers 1,3-butadiene. samples. different approaches taken 75% set 25% independent check performance. best model, based lifestyle factors, able 50% variance benzene proportion some (e.g., 3-ethenylpyridine exposure). benzo[a]pyrene 35% among similar result rest compounds. developed validated almost all VOC explain good indicators affecting but could not statistically, exception pyrene. proposal categorizing low presented, according thresholds. For both correctly classified predicted proposed models, less successfully classified.