Comparison of polychlorinated biphenyl levels across studies of human neurodevelopment.

Abstract

Polychlorinated biphenyls (PCBs) are persistent pollutants that are ubiquitous in the food chain, and detectable amounts are in the blood of almost every person in most populations that have been examined. Extensive evidence from animal studies shows that PCBs are neurotoxins, even at low doses. Interpretation of human data regarding low-level, early-life PCB exposure and subsequent neurodevelopment is problematic because levels of exposure were not similarly quantified across studies. We expressed the exposure levels from 10 studies of PCB and neurodevelopment in a uniform manner using a combination of data from original investigators, laboratory reanalyses, calculations based on published data, and expert opinion. The mainstay of our comparison was the median level of PCB 153 in maternal pregnancy serum. The median concentration of PCB 153 in the 10 studies ranged from 30 to 450 ng/g serum lipid, and the median of the 10 medians was 110 ng/g. We found that (a)) the distribution of PCB 153 exposure in most studies overlapped substantially, (b)) exposure levels in the Faroe Islands study were about 3-4-fold higher than in most other studies, and (c)) the exposure levels in the two recent U.S. studies were about one-third of those in the four earlier U.S. studies or recent Dutch, German, and northern Qu├ębec studies. Our results will facilitate a direct comparison of the findings on PCBs and neurodevelopment when they are published for all 10 studies.

Serum polychlorinated biphenyl and organochlorine insecticide concentrations in a Faroese birth cohort

“…The PCB concentrations are in agreement with previous reports from the Faroese population (25,31), and these PCB concentrations are high compared to international data on human levels of PCBs (51). The concentrations are comparable to serum levels of PCBs in Eastern Slovakia, where a hotspot is located (52).…”

Low concentrations of bisphenol a suppress thyroid hormone receptor transcription through a nongenomic mechanism

“…Thus, environmental chemicals that can produce TH insufficiency or interfere with TH signaling during development are likely to alter important developmental events (Zoeller et al, 2002). Recent epidemiologic studies have indicated the significant relationships between circulating levels of TH and exposure to environmental chemicals (Blount et al, 2006;Longnecker et al, 2003). Thus, understanding the action of environmental chemicals that can interfere with TH signaling is highly important to human health.…”

Expressing urine from a gel disposable diaper for biomonitoring using phthalates as an example

“…With respect to behaviour, gender-specific tools should be considered, if not implemented. Both DES and PCB exposures have been associated with alterations in gender-specific behaviour (Collaer & Hines, 1995;Guo et al, 1995;Longnecker et al, 2003). Standardized clinical assessments are available for newborns and paediatric populations, which can be tailored to meet particular research goals, taking into account the characteristics or physical/ biological properties of the exposure under investigation.…”