title: 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 Québec studies. Our results will facilitate a direct comparison of the findings on PCBs and neurodevelopment when they are published for all 10 studies.
authors.affiliation: Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA. longnecker@niehs.nih.gov
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Longnecker
authors.forename: Mary S
authors.initials: MS
authors.lastname: Wolff
authors.forename: Beth C
authors.initials: BC
authors.lastname: Gladen
authors.forename: John W
authors.initials: JW
authors.lastname: Brock
authors.forename: Philippe
authors.initials: P
authors.lastname: Grandjean
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Jacobson
authors.forename: Susan A
authors.initials: SA
authors.lastname: Korrick
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Rogan
authors.forename: Nynke
authors.initials: N
authors.lastname: Weisglas-Kuperus
authors.forename: Irva
authors.initials: I
authors.lastname: Hertz-Picciotto
authors.forename: Pierre
authors.initials: P
authors.lastname: Ayotte
authors.forename: Paul
authors.initials: P
authors.lastname: Stewart
authors.forename: Gerhard
authors.initials: G
authors.lastname: Winneke
authors.forename: M Judith
authors.initials: MJ
authors.lastname: Charles
authors.forename: Sandra W
authors.initials: SW
authors.lastname: Jacobson
authors.forename: Eric
authors.initials: E
authors.lastname: Dewailly
authors.forename: E Rudy
authors.initials: ER
authors.lastname: Boersma
authors.forename: Larisa M
authors.initials: LM
authors.lastname: Altshul
authors.forename: Birger
authors.initials: B
authors.lastname: Heinzow
authors.forename: James J
authors.initials: JJ
authors.lastname: Pagano
authors.forename: Allan A
authors.initials: AA
authors.lastname: Jensen
mesh_terms: D002849:Chromatography, Gas / Q000379:methods; D004785:Environmental Pollutants / Q000097:blood*; D005060:Europe; D005260:Female; D005506:Food Contamination; D006801:Humans; D018811:Maternal Exposure / Q000009:adverse effects*; D008895:Milk, Human / Q000737:chemistry / Q000187:drug effects*; D009420:Nervous System / Q000187:drug effects* / Q000196:embryology; D011078:Polychlorinated Biphenyls / Q000097:blood*; D011247:Pregnancy; D011792:Quebec; D012680:Sensitivity and Specificity; D014481:United States
chemical_list: D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls; C014024:2,4,5,2',4',5'-hexachlorobiphenyl