Comparative aspects of congener specific PCB metabolism

Borlakoglu, J.T.; Walker, C.H.

doi:10.1007/bf03190852

Cited by 46 publications

(21 citation statements)

References 11 publications

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“…Part of the elimination or change may be from metabolism or biotransformation, but excretion may also play a role. Data from field studies which began in the 1970s (Borlakoglu et al, 1988;Borlakoglu and Walker, 1989) corroborated these experimental results. Metabolic processes are occurring in avian embryos and some of those processes are disrupted (enhanced or reduced) when exposed to contaminants.…”

Section: Introductionsupporting

confidence: 86%

“…Upper graph is standardized (congeners as a % of total PCBs) and lower graph has been normalized (mean ¼ 0, SD ¼ 1). et al., 2007), and corroborated by field data beginning as early as the 1970s (Borlakoglu and Walker, 1989;Borlakoglu et al, 1988), the information for embryonic metabolism is much more limited and for the most part does not support metabolism or biotransformation of PCB congeners by avian embryos. There was no difference in total PCBs, either in concentration (mg/g wet wt.)…”

Section: Discussionmentioning

confidence: 58%

See 1 more Smart Citation

Incubation stage and polychlorinated biphenyl (PCB) congener patterns in an altricial and precocial bird species

Custer¹,

Custer²,

Thyen³

et al. 2014

Environmental Pollution

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Section: Introductionsupporting

confidence: 86%

Section: Discussionmentioning

confidence: 58%

Incubation stage and polychlorinated biphenyl (PCB) congener patterns in an altricial and precocial bird species

Custer¹,

Custer²,

Thyen³

et al. 2014

Environmental Pollution

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“…PCB-28 and PCB-52 were detected in only a small proportion of cases, although the LOD was very low. These compounds are more easily metabolized than are other PCBs because of the arrangement of their chlorine atoms and their lower degree of chlorination (Borlakoglu and Walker 1989). δ-HCH was not detected in any individual, and although Pe-CB and PCB-101 were detected in a few samples, their LODs were higher than other OCs; these three compounds were therefore excluded from statistical analyses.…”

Section: Resultsmentioning

confidence: 99%

Organochlorine Exposure and Colorectal Cancer Risk

Howsam

Grimalt

Guinó

et al. 2004

Environ Health Perspect

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Organochlorine compounds have been linked to increased risk of several cancers. Despite reductions in their use and fugitive release, they remain one of the most important groups of persistent pollutants to which humans are exposed, primarily through dietary intake. We designed a case–control study to assess the risk of colorectal cancer with exposure to these chemicals, and their potential interactions with genetic alterations in the tumors. A subsample of cases (n = 132) and hospital controls (n = 76) was selected from a larger case–control study in Barcelona, Catalonia, Spain. We measured concentrations in serum of several organochlorines by gas chromatography. We assessed point mutations in K-ras and p53 genes in tissue samples by polymerase chain reaction/single-strand conformation polymorphism and assessed expression of p53 protein by immunohistochemical methods. An elevated risk of colorectal cancer was associated with higher serum concentrations of mono-ortho polychlorinated biphenyl (PCB) congeners 28 and 118. The odds ratio for these mono-ortho PCBs for middle and higher tertile were, respectively, 1.82 [95% confidence interval (CI), 0.90–3.70] and 2.94 (95% CI, 1.39–6.20). α-Hexachlorocyclohexane, hexachlorobenzene, and p,p′-DDE (4,4′-dichlorodiphenyltrichloroethene) showed nonsignificant increases in risk. Risk associated with mono-ortho PCBs was slightly higher for tumors with mutations in the p53 gene but was not modified by mutations in K-ras. Mono-ortho PCBs were further associated with transversion-type mutations in both genes. These results generate the hypothesis that exposure to mono-ortho PCBs contributes to human colorectal cancer development. The trend and magnitude of the association, as well as the observation of a molecular fingerprint in tumors, raise the possibility that this finding may be causal.

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“…They emphasized the importance of low-dose effects, which in their study meant that they found stronger associations between the 2nd and 3rd sextiles relative to the 1st when they compared the 5th and 6th sextiles to the 1st. There is, however, a complication in interpretation of these low-dose results, in that if indeed the primary association with diabetes is stronger with lower-chlorinated non-dioxin-like congeners, these are much more rapidly metabolized than more highly chlorinated congeners (Borlakoglu and Walker 1989; Öberg et al 2002). Thus, elevations of serum concentrations of low-chlorinated congeners are more likely to be found in the lower quartiles of exposures.…”

Section: Discussionmentioning

confidence: 99%

Diabetes Prevalence in Relation to Serum Concentrations of Polychlorinated Biphenyl (PCB) Congener Groups and Three Chlorinated Pesticides in a Native American Population

Aminov

Haase

Rej

et al. 2016

Environ Health Perspect

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Background:Exposure to persistent organic pollutants (POPs) is known to increase risk of diabetes.Objective:To determine which POPs are most associated with prevalence of diabetes in 601 Akwesasne Native Americans.Methods:Multiple logistic regression analysis was used to assess associations between quartiles of concentrations of 101 polychlorinated biphenyl (PCBs) congeners, congener groups and three chlorinated pesticides [dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and mirex] with diabetes. In Model 1, the relationship between quartiles of exposure and diabetes were adjusted only for sex, age, body mass index (BMI), and total serum lipids. Model 2 included additional adjustment for either total PCBs or total pesticides.Results:Total serum PCB and pesticide concentrations were each significantly associated with prevalence of diabetes when adjusted only for covariates (Model 1), but neither showed a significant OR for highest to lowest quartiles after additional adjustment for the other (Model 2). When applying Model 2 to PCB congener groups and individual pesticides, there were significant omnibus differences between the four quartiles (all ps < 0.042) for most groups, with the exception of penta- and hexachlorobiphenyls, DDE and mirex. However, when comparing highest to lowest quartiles only non- and mono-ortho PCBs [OR = 4.55 (95% CI: 1.48, 13.95)], tri- and tetrachloro PCBs [OR = 3.66 (95% CI: 1.37, –9.78)] and HCB [OR = 2.64 (95% CI: 1.05, 6.61)] showed significant associations with diabetes. Among the non- and mono-ortho congeners, highest to lowest quartile of dioxin TEQs was not significant [OR = 1.82 (95% CI: 0.61, 5.40)] but the OR for the non-dioxin-like congeners was [OR = 5.01 (95% CI: 1.76, 14.24)].Conclusion:The associations with diabetes after adjustment for other POPs were strongest with the more volatile, non-dioxin-like, low-chlorinated PCB congeners and HCB. Because low-chlorinated congeners are more volatile, these observations suggest that inhalation of vapor-phase PCBs is an important route of exposure.Citation:Aminov Z, Haase R, Rej R, Schymura MJ, Santiago-Rivera A, Morse G, DeCaprio A, Carpenter DO, and the Akwesasne Task Force on the Environment. 2016. Diabetes prevalence in relation to serum concentrations of polychlorinated biphenyl (PCB) congener groups and three chlorinated pesticides in a Native American population. Environ Health Perspect 124:1376–1383; http://dx.doi.org/10.1289/ehp.1509902

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Comparative aspects of congener specific PCB metabolism

Cited by 46 publications

References 11 publications

Incubation stage and polychlorinated biphenyl (PCB) congener patterns in an altricial and precocial bird species

Incubation stage and polychlorinated biphenyl (PCB) congener patterns in an altricial and precocial bird species

Organochlorine Exposure and Colorectal Cancer Risk

Diabetes Prevalence in Relation to Serum Concentrations of Polychlorinated Biphenyl (PCB) Congener Groups and Three Chlorinated Pesticides in a Native American Population

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