In Utero DDT and DDE Exposure and Neurodevelopment in Children of Farmworkers

Details

• Personal Author:
  Barr DB ; Bradman A ; Eskenazi B ; Fenster L ; Jewell NP ; Marks AR ; Rodriguez ME
• Description:
  Introduction: Dichlorodiphenyltrichloroethane (DDT), a persistent organochlorine pesticide, breaks down slowly in soil, has a long half-life, and bio-accumulates in plants and animals. Although DDT was banned in the U.S. in 1972 and in Mexico in 2000, it continues to be used in other malaria-endemic areas. There is substantial animal evidence that DDT exposure in utero and during early postnatal life impacts neurodevelopment. However, few studies have examined these associations in humans. A North Carolina study found levels of DDE, a metabolite of DDT, to be dose-related to neonatal hyporeflexia (Brazelton Neonatal Behavioural Assessment Scale), but this was not confirmed in a smaller study from New York. The latter study also did not find an association with 6- and 12-month olds' performance on the Fagan Test of Infant Intelligence. However, in a small Spanish study (n=92), cord serum DDE was negatively associated with 13-month olds' cognitive, psychomotor, and social development (Bayley Scales of Infant Development, Griffiths Scales of Infant Development). Aim: The present study aims to investigate the relationship of in utero DDT/DDE exposure and neurodevelopment of children from primarily Mexican farmworker families in the Salinas Valley, California. Methods: Participants were drawn from the CHAMACOS project, a longitudinal birth cohort study of pesticides and other environmental exposures and the health of pregnant women and their children. This analysis includes approximately 350 singletons with a maternal blood collected during pregnancy (approximately 26 weeks gestation) and measured for p,p- DDT, p,p- DDE, and o,p- DDT by gas chromatography high-resolution mass spectrometry. Results: p,p -DDT, p,p -DDE, and o,p -DDT were detected in almost all samples. Geometric mean levels and 95% confidence intervals were: p,p -DDT = 19.7 ng/g lipid (16.7, 23.2); p,p -DDE = 1361 ng/g lipid (1201, 1542); and o,p -DDT = 1.6 ng/g lipid (1.4, 1.8). Crude analyses indicate a relationship between serum levels and some measures of mental and psychomotor development at different ages: Among 6-month olds, p,p -DDT was negatively associated with Bayley Psychomotor Development Index (PDI) (β= -1.6 points per log10 unit increase, p =0.08), but not the Bayley Mental Development Index (MDI). Among 12-month olds, o,p -DDT p,p -DDT, and p,p -DDE were all negatively associated with PDI (β= -2.4, p =0.04; β= -2.6, p =0.01; and β= -2.7, p =0.04, respectively). o,p -DDT and p,p -DDT were also associated with MDI at 12 months (β= -2.0, p =0.02; β= -1.2, p =0.10, respectively). Among 24-month olds there were no associations with PDI, but o,p -DDT was associated with MDI (β= -2.3, p =0.06). We will determine whether these findings remain after adjustment for potential confounders. Conclusion: In summary, we find preliminary evidence for an association between in utero exposure to DDT and DDE and neurodevelopment in children, but the associations may vary with age. [Description provided by NIOSH]
• Subjects:
  Demography Environmental Monitoring Epidemiology Hazardous Substances Hematologic Tests Insecticides Occupational Health Pregnancy Risk Assessment Risk Factors Safety Surveys And Questionnaires Teratogenesis Urine Urogenital System

  More +
• Keywords:
  Biological-monitoring Blood-analysis Blood-sampling Children Demographic-characteristics Exposure-assessment Exposure-levels Health-hazards Health-surveys Pesticides Pesticides-and-agricultural-chemicals Prenatal-exposure Reproductive-effects Risk-analysis Risk-factors Statistical-analysis Teratology Urine-chemistry

  More +
• ISSN:
  1044-3983
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary ; Proceedings
• Place as Subject:
  California ; Georgia ; OSHA Region 4 ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  16
• Issue:
  5
• NIOSHTIC Number:
  nn:20033349
• Citation:
  Epidemiology 2005 Sep; 16(5):S101
• CAS Registry Number:
  3,5,6-Trichloro-2-pyridinol (CAS RN 6515-38-4) ; Chlorpyrifos (CAS RN 2921-88-2) ; DDT (CAS RN 50-29-3) ; Malathion (CAS RN 121-75-5) ; Naphthalene (CAS RN 91-20-3) ; Pentachlorophenol (CAS RN 87-86-5)
• Federal Fiscal Year:
  2005
• Performing Organization:
  University of California, Berkeley
• Peer Reviewed:
  False
• Start Date:
  20010930
• Source Full Name:
  Epidemiology
• End Date:
  20060929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:0c97c1f2435c42fadace67c870f0272dd8fcf471804388cd565e1bcaae2f92cdcdc35192180fc1be55d848f0ef9effafc727262bcba636563d19ca0b78fcb1f0
• Download URL:
  https://stacks.cdc.gov/view/cdc/188964/cdc_188964_DS1.pdf
• File Type:
  [PDF - 326.70 KB ]