Maternally mediated exposure to PCBs may be detrimental to fetal growth, particularly in boys. These effects apparently are not persistent. Interpretation of greater childhood growth of girls is unclear.

We examined predictors of organochlorine concentrations in serum specimens from women who were pregnant in the 1960s and participated in the Child Health and Development Study in the San Francisco Bay Area of California. That study enrolled pregnant women at the Kaiser-Permanente Medical Facilities, conducted interviews, and drew blood specimens; these specimens were centrifuged and the resulting serum specimens were frozen and placed in long-term storage. For the current investigation, organochlorines were measured by dual-column GC-electron capture detection in specimens collected in 1963-1967 from 399 pregnant women during the second and third trimesters. Using multiple linear regression models adjusted for serum lipids, we evaluated factors predicting concentrations of 11 polychlorinated biphenyl (PCB) congeners, their sum, and several pesticides and metabolites. Variables evaluated were age, race, place of birth, date of blood draw, body mass index, occupation, past residence on a farm, parity, and duration of pregnancy at blood draw. Concentrations of highly chlorinated PCBs and the sum of the PCBs increased with age. Concentrations of certain PCB congeners, as well as the sum, were significantly higher among nonwhites and increased with calendar date of blood draw. (italic)p,p(/italic) -DDT and (italic)p,p(/italic) -DDE concentrations were about 50% higher for nonwhites compared with whites and for those born in California or the southeastern United States versus elsewhere in the United States. Higher body mass index was associated with lower concentrations of several PCBs and (italic)p,p(/italic) -DDE but with higher heptachlor epoxide and DDT levels. The increase in use of PCBs during the 1960s is apparently detectable as increasing concentrations in maternal sera between 1963 and 1967. Marked racial and regional differences in serum pesticide levels were likely caused by geographic variation in previous agricultural and vector-control uses. The relationship to body mass index appears to be complex.

At the concentrations studied in this sample, DDT compounds did not appear to impair fetal or 5-year growth.

The accumulation of a group of non-and mono-ortho (coplanar) PCB congeners in aquatic food webs is of special interest due to their dioxin-like toxicities. Furthermore, higher octanol-water partition coefficients than homologs with greater ortho-substitution suggest the potential for selective accumulation of the coplanar congeners. We quantified 47 PCB congeners containing 0-3 ortho-chlorines from six homolog groups in sediments, plankton, and fish from Green Bay, WI, using conventional and multidimensional gas chromatography with electron capture detection. Of the congeners exhibiting dioxin-like toxicity, the only nonortho-substituted congener quantifiable in any of the matrices was IUPAC 77, but all of the toxic mono-ortho-substituted congeners were detected and quantified. Penta-, hexa-, and heptachloro congeners were enriched relative to other congeners in sediments and fish located more distant from the main source of the bay, whereas trichloro congeners were depleted. The same homolog groups also became more enriched as PCBs moved to higher levels in the ecosystem from sediment to plankton to fish, while trichloro congeners were depleted. Enrichment patterns of the most toxic (dioxin-like) congeners were also influenced mainly by total chlorine substitution; the degree of orthosubstitution did not systematically affect accumulation in plankton and fish.