نتایج جستجو برای: pcb
تعداد نتایج: 5063 فیلتر نتایج به سال:
BACKGROUND Epidemiologic studies of postnatal PCB exposure and behavior have not reported consistent evidence of adverse associations, possibly because of challenges in exposure estimation. We previously developed a pharmacokinetic model to improve estimation of children's PCB exposure. OBJECTIVES We aimed to assess whether estimated serum PCB levels in infancy are associated with attention d...
Polychlorinated biphenyls (PCBs) remain chemicals of concern more than three decades after the ban on their production. Technical mixture-based total PCB measurements are unreliable due to weathering and degradation, while detailed full congener specific measurements can be time-consuming and costly for large studies. Measurements using a subset of indicator PCBs (iPCBs) have been considered ap...
The development of an area-based polychlorinated biphenyl (PCB) food-web bioaccumulation model enabled a critical evaluation of the efficacy of sediment quality criteria and prey tissue residue guidelines in protecting fish-eating resident killer whales of British Columbia and adjacent waters. Model-predicted and observed PCB concentrations in resident killer whales and Chinook salmon were in g...
1. A: Blood level of PCBs before and after the treatment in nine subjects. Closed circles show blood PCB level of each subject. Open circles show the mean blood level of PCB. B: Correlation between initial PCB concentration and reduction ratio (%) of PCB after colestimide treatment. (R= 0.64) C: Correlation of alteration in PCB and dioxin level after colestimide treatment. Data expresses the pe...
The reproductive success of wild birds has been affected by exposure to multiple contaminants. Reproduction of captive American kestrels (Falco sparverius) was suppressed when adult birds were exposed to dietary polychlorinated biphenyls (PCBs). In this study, the reproductive effects of in ovo exposure to PCBs is explored, along with determining effects on reproduction in second-generation bir...
The present study examined the feasibility of using a combination of gonadotropin releasing hormone antagonist (GnRH-A) and testosterone in the prevention of procarbazine induced germinal aplasia. Daily injections of GnRH-A or vehicle were given to adult male rats for 21 days prior to procarbazine (PCB) administration and continued until 2 days after the second of two doses of procarbazine (200...
Polychlorinated biphenyls (PCB) are potent inducers of hepatic microsomal CO-binding hemoprotein P-448 (P1-450) and of delta-aminolevulinate synthetase (ALAS) activity. Inorganic cobalt was able to block PCB induction of cytochrome P-448 and to modify the PCB effect on ALAS activity in a time-dependent manner. PCB were also found to decrease the activity of delta-aminolevulinic acid dehydratase...
mangrove sediments were collected during wet and dry seasons from nine stations in khamir,laft and natural reservoir mangrove-dense areas of hormozgan province in the south of iran. σ pcbs ranged from 5.33 to 15.5 ng/g dry weight and the dominant congener was no.153. average σ ddts for khamir and laft mangroves were 16.58 ± 1.51 and 18.8 ± 9.98 ng/g dry weight. ddt was more abundant than dde an...
many of the persistent organic pollutants (pops) with endocrine disrupting properties are monitored regularly by risk assessors with limited resources, where analytical procedures are usually laborious, expensive, and not ecofriendly. moreover, these analyses were frequently advanced aiming one class of pollutants, consequently inefficient to correspond the demand of monitoring a quickly rising...
Introduction To employ improved countermeasures against PCB sources and to reduce the risk to aquatic biota, it is important to identify sources and migration pathways and ascertain their contribution to PCB pollution . Thus, a wider range of studies is required to identify potential PCB sources in the environment. The objective of this study is to identify PCB pollution sources affecting Tokyo...
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