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Two‐year chronic bioassays were conducted by using B6C3F1 female mice fed several concentrations of two different mixtures of coal tars from manufactured gas waste sites or benzo(a)pyrene (BaP). The purpose of the study was to obtain estimates of cancer potency of coal tar mixtures, by using conventional regulatory methods, for use in manufactured gas waste site remediation. A secondary purpose was to investigate the validity of using the concentration of a single potent carcinogen, in this case benzo(a)pyrene, to estimate the relative risk for a coal tar mixture. The study has shown that BaP dominates the cancer risk when its concentration is greater than 6,300 ppm in the coal tar mixture. In this case the most sensitive tissue site is the forestomach. Using low‐dose linear extrapolation, the lifetime cancer risk for humans is estimated to be: Risk < 1.03 × 10−4 (ppm coal tar in total diet) + 240 × 10−4 (ppm BaP in total diet), based on forestomach tumors. If the BaP concentration in the coal tar mixture is less than 6,300 ppm, the more likely case, then lung tumors provide the largest estimated upper limit of risk, Risk < 2.55 × 10−4 (ppm coal tar in total diet), with no contribution of BaP to lung tumors. The upper limit of the cancer potency (slope factor) for lifetime oral exposure to benzo(a)pyrene is 1.2 × 10−3 per μg per kg body weight per day from this Good Laboratory Practice (GLP) study compared with the current value of 7.3 × 10−3 per μg per kg body weight per day listed in the U.S. EPA Integrated Risk Information System.

Polycyclic aromatic hydrocarbons (PAHs) were identified to be one of the major toxic air pollutants in urban environment PAHs are mostly formed during incomplete combustion or pyrolysis of organic material According to Serbian National Legislation, benzo(a)pyrene (BaP) concentration in total suspended particles (TSP) in ambient air in the Belgrade metropolitan area has been determined in the last ten years, as a part of a local air pollution monitoring program performed by the Public Health Institute of Belgrade and funded by Belgrades Municipality Air samples for analysis of BaP in suspended particles have been collected (as 24 h sample once per month) at selected monitoring sites within the municipal air quality monitoring network At the beginning, according to National Regulation, all samples were taken as total suspended particles (TSP) Since mid-2008, the procedure of sampling methodology was harmonized with EU requirements and solid fraction PM(10) has been collected and analyzed using GC/MS In this study, we have analyzed results of TSP collected between 2005 and 2008 Looking through the results obtained during the period of a whole year, it can be noticed that concentrations of BaP were much higher during winter season at almost all measuring sites

ABSTRACT OF THE THESISBySanjiwani MehardaMaster of Science in Environmental Health ScienceUniversity of California, Irvine,2016Professor Ulrike Luderer, Chair In contrast to gametogenesis in males, oocytes in females are not continually replenished during reproductive life. Exposure to ovotoxicants during or after embryogenesis can lead to irreversible ovarian dysgenesis or premature ovarian failure (POF). Benzo [a] pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) and a component of air pollution. PAHs are formed as a result of incomplete combustion of organic materials and are ubiquitous environmental contaminants. Found in cigarette smoke, polycyclic aromatic hydrocarbons are "toxic to and destructive to oocytes in several animal test systems." Men and women who smoke have decreased fertility. Our study for the first time uses the lacZ transgenic MutaTMMouse, mouse model to study female reproductive consequences of prenatal exposure to BaP Pregnant transgenic MutaMouse were treated with 0, 10, 20 or 40 mg/kg/d BaP orally from gestational day 7 through 16, which represents the major period of organogenesis. The F1 female offspring were euthanized at 10 wk. of age and ovaries were processed for differential ovarian follicle counting. Transplacental BaP exposure caused very significant dose-related decreases in primordial, primary and secondary follicles in the ovaries of F1 MutaMice. There was prominent ovarian tissue destruction at the higher doses of BaP exposure. Our results show that maternal exposure to BaP during gestation is highly damaging to the developing ovaries of the F1 female offspring in Muta mice as it is in other mouse strains that have been studied. Therefore, this model is an excellent model not only for observing the mutation effects but also for showing the reproductive effects.Our findings in the mouse are relevant to humans, as ovarian development in humans and mice is very similar. Increasing evidence regarding PAH exposure and its harmful effects leads us to believe that additional regulations to reduce PAH exposure are needed at the government level. In addition, campaigns to increase awareness among the general population about PAHs are needed, as "Prevention is the key".