Suchergebnisse

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".

Abstract
Exposure of infants to chemicals during their development will have major effects on their health. One of the major exposures of infants to chemicals is through their food. The main structure of infant food is milk, which is high in fat. There is a possibility of accumulation of environmental pollution, including benzo (a) pyrene (BaP). In this systematic review, the amount of BaP in infant milk was surveyed for this purpose. The chosen keywords were: benzo (a) pyrene, BaP, Infant formula, dried milk, powdered milk, and baby food. A total of 46 manuscripts were found in the scientific database. After initial screening and quality assessment, 12 articles were selected for extraction of data. By meta-analysis, the total estimate of BaP in baby food was calculated to be 0.078 ± 0.006 μg/kg. Estimation of daily intake (EDI) and Hazard Quotient (HQ) for noncarcinogenic risk and Margin of exposure (MOE) for carcinogenic risk were also calculated for three age groups 0–6 months, 6–12 months, and 1–3 years. HQ was lower than 1 and MOE was more than 10,000 for three age groups. Therefore, there is no potential carcinogenic and non-carcinogenic risk for infant health.

Polycyclic aromatic hydrocarbons (PAHs) are products of the incomplete combustion or pyrolysis of organic material and they are among the most harmful compounds. During process of meat smoking, wood combustion is one of the most important sources of PAH compounds, which can be adsorbed by the surface of meat. The EFSA (European Food Safety Authority) Panel on Contaminants in the Food Chain (CONTAM Panel) recommended to the member states of European Union to use the sum of benzo[a] pyrene (BaP), benz[a] anthracene (BaA), benzo[b] fluoranthene (BbF) and chrysene (CHR), (PAH4 compounds), as a marker for the occurrence and impact of carcinogenic PAHs in food, instead of benzo[a]pyrene. The maximum content of BaP and sum of all four compounds (PAH4) has been established by European Commission Regulation No. 835/2011. For smoked foods, from 1st September 2014, the maximum BaP content was lowered to 2 mu g/kg, while the content of PAH4 is allowed to 12 mu g/kg. The new maximum residue limits (MRL) both for BaP and sum of PAH4 compounds in smoked meat and meat products were defined by the legislation of Serbia, as well, and it is in accordance with EU regulation. The aim of this paper was the validation of the method for identification and determination of benzo[a] pyrene, chrysene, benz[a] anthracene and benzo[b] fluoranthene in smoked meat and smoked meat products. Accelerated solvent extraction (ASE) was used for extraction of lipids and lipophilic compounds. Solid Phase Extraction (SPE) was used in order to remove lipids from analysed samples. High-performance liquid chromatographic with fluorescence detection (HPLC-FL) was applied for identification and quantification of PAH4 compounds. Fluorescence detector operated at excitation/emission wavelength 275/385 nm for BaA and CHR, 256/446 nm for BbF and 260/410 nm for BaP, respectively. On the base of experimental results, it is possible to conclude as follows: The in-house validation procedure of the method meets all criteria (applicability, specificity, repeatability, reproducibility, recovery, LOD and LOQ) set out by EU Regulation No. 836/2011. The method is suitable for operative control of PAH4 content in smoked meat products.

ABSTRACT: Benzo[a]pyrene is a polycyclic aromatic hydrocarbon which has been related with adverse health outcomes. Food is a source of benzo[a]pyrene; which is produced during industrial processing or cooking. Objective: To review information about benzo(a)pyrene formation in food, biological activation, association with cancer, food content and regulation of benzo(a)pyrene content in human food. Methods: A literature search from national and international scientific databases was developed. Results: benzo[a]pyrene ingested is absorbed by the intestine metabolized and activated, predominantly, by the liver. Animal studies have associated benzo[a]pyrene with esophagus, stomach, intestine, skin, bladder, lung, and liver cancer. Benzo[a]pyrene is potentially toxic to the fetus, due to it passes trough placenta. Benzo[a]pyrene amounts in some foods exceed the maximum level allowed by the European Commission; which periodically updates legislation on this topic. In Colombia there is not regulation about benzo[a]pyrene. Conclusion: benzo[a]pyrene in food generates compounds that may be associated with cancer, mainly gastrointestinal cancer. The European Commission regularly updates regulation about benzo[a]pyrene content in foods. Colombia does not have regulation on this topic. ; RESUMEN: El benzo(a)pireno es un hidrocarburo aromático policíclico con efectos adversos para la salud, una de las fuentes es la ingestión de alimentos, formados durante procesamiento industrial o en el hogar. Objetivo: indagar sobre la formación de benzo(a)pireno en los alimentos, su activación biológica, relación con el cáncer, contenido en los alimentos y la normativa que regula la cantidad en alimentos para humanos. Materiales y métodos: se realizó una búsqueda bibliográfica de artículos publicados en las bases de datos nacionales e internacionales. Resultados: el benzo(a)pireno ingerido con los alimentos se absorbe por el intestino, se metaboliza predominantemente en el hígado, allí se activa y puede inducir cáncer de diversa localización, como esófago, estómago, intestino, piel, vejiga, pulmón e hígado, evidenciado en estudios experimentales en animales. El benzo(a)pireno atraviesa la placenta y es potencialmente tóxico para el feto. Las cantidades en algunos alimentos exceden las máximas permitidas por la Comisión Europea entidad que periódicamente actualiza las normas sobre el tema. En Colombia no se encontró reglamentación. Conclusión: el benzo(a)pireno procedente de alimentos genera compuestos capaces de desarrollar cáncer principalmente del tracto gastrointestinal. La Comisión Europea actualiza periódicamente la normativa que regula el contenido de benzo(a)pireno en alimentos, Colombia carece de normas sobre el tema.