PCBs and OH-PCBs in Serum from Children and Mothers in Urban and Rural U.S. Communities

Abstract

East Chicago, Indiana is a heavily-industrialized community bisected by the Indiana Harbor and Ship Canal, which volatilizes ~7.5 kg/yr polychlorinated biphenyls (PCBs). In contrast, the rural Columbus Junction, Iowa area has no known current or past PCB industrial sources. Blood from children and their mothers from these communities were collected April 2008-January 2009 (n=177). Sera were analyzed for all 209 PCBs and 4 hydroxylated PCBs (OH-PCBs). Sum PCBs ranged from non-detect to 658 ng/g lw (median = 33.5 ng/g lw). Sum OH-PCBs ranged from non-detect to 1.2 ng/g fw (median = 0.07 ng/g fw). These concentrations are similar to those reported in other populations without high dietary PCB intake. Differences between the two communities were subtle. PCBs were detected in more East Chicago mothers and children than Columbus Junction mothers and children, and children from East Chicago were enriched in lower-molecular weight PCBs. East Chicago and Columbus Junction residents had similar levels of total and individual PCBs and OH-PCBs in their blood. Concentrations of parent PCBs correlated with concentrations of OH-PCBs. This is the first temporally- and methodologically-consistent study to evaluate all 209 PCBs and major metabolites in two generations of people living in urban and rural areas of the United States.

An Extended Structure–Activity Relationship of Nondioxin-Like PCBs Evaluates and Supports Modeling Predictions and Identifies Picomolar Potency of PCB 202 Towards Ryanodine Receptors

“…Here, we evaluated and supported the predictions of a RyR-based neurotoxic QSAR that has been used to define NEQs for NDL PCBs (Rayne and Forest, 2010). As predicted, PCB 202 is a highly RyR potent PCB congener, and whereas it is detected in human and environmental samples, it likely does not represent a large percentage of total PCB burdens (Marek et al, 2013;Stahl et al, 2009). However, similar to TCDD in the TEQ scheme, PCB 202 could act as a reference compound for which PCB mixture toxicity toward the RyR is based.…”

“…Deficits in children have included lowered IQ scores, impaired learning and memory, and attention deficit (Jacobson and Jacobson, 1996;Lonky et al, 1996;Stewart et al, 2008). It is well recognized that PCB residues in these samples are complex mixtures but neurotoxic outcomes due to PCB mixture exposure have been largely ascribed to NDL congeners because they are found in relatively high concentrations in the brains of human and experimental animals that display neuropsychological deficits (Mitchell et al, 2012;Pessah et al, 2010) NDL PCBs also constitute the majority of the total PCB burden in both human and environmental samples (Hwang et al, 2001(Hwang et al, , 2006Marek et al, 2013;Stahl et al, 2009) and further understanding the contribution of the RyR, alone or in combination with other modes of NDL PCB neurotoxicity (see "Introduction" section), would help further elucidate risks in human populations.…”

“…PCB-197, like PCB 202, has 8 chlorines, but is predicted to have relatively lower RyR-activity due to its para-chloro substitutions. All the congeners selected have been detected in human samples (Koh et al, 2015;Marek et al, 2013; http://www. ewg.org/sites/humantoxome/chemicals/index), with several congeners, including, PCB 11,20,28,95,99, and 118, being frequently detected in both humans and the environment (Grimm et al, 2015;Stahl et al, 2009).…”

PCB Concentrations and Dioxin‐like Activity in Blood Samples from Danish School Children and Their Mothers living in Urban and Rural Areas

“…It may also be due to higher exposure levels from the urban surroundings. In a study from the USA, where urban and rural communities also were compared, a difference in concentration level was not found, but the presence of PCBs in the serum samples was significantly more frequent in the urban samples [44]. In our study, PCB 28 was the only PCB congener that showed higher rural than urban concentrations, which is notable, because it indicates that children living in the rural area are exposed to higher levels of volatized PCBs, perhaps from school or living buildings.…”

Different pattern of contamination by legacy POPs in two populations from the same geographical area but with completely different lifestyles: Canary Islands (Spain) vs. Morocco

“…Despite their ubiquity throughout the planet, environmental concentrations in a particular region are conditioned by the past use of these chemical compounds in it. So it has been reported that in urban areas and in the most industrialized regions the levels of contamination by PCBs of the population are much higher than in rural areas (Ampleman et al, 2015;Marek et al, 2013). In this sense, Spain and Morocco are completely different, and therefore it is expected that the levels of contamination by these chemicals are also different.…”