Blood persistent organochlorine pesticides in pregnant women in relation to physical and environmental variables in The Hokkaido Study on Environment and Children's Health

The aim of this study was to document the exposure levels of pregnant women in Hokkaido to persistent organochlorine (POC) pesticides and the relationship between the body burdens of these pesticides and the study population's characteristics, such as age, pre-pregnancy body weight and calendar year in which blood was collected. From 2002 to 2005, whole blood samples were obtained from 186 pregnant women (aged 17 to 47 years) from the population of 514 women registered with the Sapporo Toho hospital cohort of the Hokkaido Study. Blood samples were analyzed by GC/NCIMS and GC/HRMS to quantify 29 POC pesticides. The subjects' demographic details were obtained from medical records and self-administered questionnaires. The Jonckheere–Terpstra test was used to determine relevant trends in the chemical concentrations of these pesticides and their relationship to the subjects' demographic details. Twenty-one of the 29 targeted compounds (including pesticides that have never been used in Japan, such as Mirex, Parlar-26 and Parlar-50) were detected in whole blood samples, and their log-transformed concentrations were found to significantly correlate with each other. The concentrations of p,p′-DDD, o,p′-DDE, p,p′-DDE, Parlar-26 and Parlar-50 declined from 2002 to 2005 (p < 0.05). The pesticide concentrations appeared to have stronger associations with past conception than with parity, with most pesticide concentrations declining in a manner that appeared inversely related to past conceptions (p < 0.05). Maternal age was positively associated with the following pesticide concentrations: p,p′-DDE, chlordanes group, cis-heptachlorepoxide, β-HCH and mirex. Maternal pre-pregnancy body weight was positively associated with the concentrations of dieldrin, HCB, β-HCH, Parlar-26 and Parlar-50, and appeared to be more strongly related to the body burdens of POC pesticides when compared with BMI associations. Further studies are required to evaluate the effects of POC pesticides on human health with regard to reproductive outcomes and child development.

► Correlations were found in log-transformed blood concentrations of most pesticides.
► Three pesticides without history of usage in Japan showed high detection rates.
► The pesticide concentrations declined in inverse association with past conceptions.
► Maternal age was positively associated with the concentrations of nine pesticides.