نتایج جستجو برای: pcbs
تعداد نتایج: 4067 فیلتر نتایج به سال:
Environmental exposures that affect accumulation of polychlorinated biphenyls (PCBs) in humans are complex and not fully understood. One challenge in linking environmental exposure to accumulation is determining variability of PCB concentrations in samples collected from the same person at different times. We hypothesized that PCBs in human blood serum are consistent from year to year in people...
The aim of this research is to develop a silica gel and alumina column chromatography for separation of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) into two groups. This is achieved by optimizing the cut-off volume of eluting solvent and weight ratio of silica gel and alumina. In this process mixture of PAHs and PCBs divide in two groups and simultaneously o...
polychlorinated biphenyls (pcbs) have been widely used to flame-retard products common in homes and theworkplace, and subsequently. polychlorinated biphenyls (pcbs) typify a class of highly toxic, stable aromaticpollutants. pcbs are recently being scrutinized for potential environment damage in groundwater and in theatmosphere. the elimination of chemical pollutants from a contaminated environm...
The concentrations of methoxylated polychlorinated biphenyls (MeO-PCBs) and hydroxylated polychlorinated biphenyls (OH-PCBs) were measured in the sewage sludge samples collected from twelve wastewater treatment plants in China. Two MeO-PCB congeners, including 3'-MeO-CB-65 and 4'-MeO-CB-101, were detected in three sludge with mean concentrations of 0.58 and 0.52 ng/g dry weight, respectively. O...
پژوهش حاضر به منظور تعیین سطوح پلیکلرو بیفنیل ( در بافت پوست و عضله ماهی کپور و اردک ماهی تالاب انزلی (در بخش غربی تالاب، آبکنار) در دو فصل پاییز و زمستان (آذر ماه 1388 و اسفند ماه 1388 ) انجام شده است. تعداد 9 نمونه از هر گونه ماهی کپور و اردک ماهی در هر فصل بطور تصادفی از طریق تور ماهیگیری گوشگیر جمعآوری گردیدند. بافتهای پوست و عضله ماهیها پس از زیستسنجی تفکیک شده و آنالیز PCBsبا استفا...
The toxic equivalency concept used for the risk assessment of polychlorinated biphenyls (PCBs) is based on the aryl hydrocarbon receptor (AhR)-mediated toxicity of coplanar dioxin-like (DL) PCBs. Most PCBs in the environment, however, are non-dioxin-like (NDL) PCBs that cannot adopt a coplanar structure required for AhR activation. For NDL-PCBs, no generally accepted risk concept is available b...
Concentrations of several congeners and classes of organohalogen contaminants (OHCs) and/or their metabolites, namely organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), hydroxylated-PCBs (OH-PCBs), methylsulfonyl-PCBs (MeSO(2)-PCBs), polybrominated diphenyl ether (PBDE) flame retardants, and OH-PBDEs, were measured in cerebrospinal fluid (CSF) of short-beaked common dolphins (n ...
This study aimed to assess the occurrence, distribution, toxicity equivalency and health risks of dl-PCBs (dioxin-like PCBs) from nine sites collected in surface sediments Liaohe River Protected Area. ?dl-PCBs concentrations range 79.2 365.1 pg/g. Sediment profiles showed that pentachlorobiphenyl is most abundant congener among all sampling sites. The results principal component analysis cluste...
Polychlorinated biphenyls (PCBs) are highly toxic environmental contaminants that can cause irreversible damage in humans and wildlife. The mechanism of toxicity is not clear, but biotransformation products such as hydroxy PCBs (OH-PCBs) are a major concern. Efforts to elucidate the metabolism of PCBs and their metabolites, however, have paid little attention to the structure of the compound to...
background: polychlorinated biphenyls (pcbs) are synthetic aromatic compounds containing two benzene rings with one to ten chlorine atoms. there are concerns about the health risks of these compounds in the environment due to their toxicity, persistence, and biological accumulation. pcbs wastes must be treated before being discharged to the environment because they will pollute the water, soil,...
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