Effects of PCBs, p,p'-DDT, p,p'-DDE, HCB and beta-HCH on thyroid function in preschool children

Occup Environ Med. 2008 Jul;65(7):452-7. doi: 10.1136/oem.2007.032763. Epub 2007 Oct 12.

Abstract

Objective: Several studies have shown that some organochlorine compounds (OCs) can interfere with the thyroid system. As thyroid hormones (THs) are essential for normal brain development, it is important to study the association between THs and OCs during pregnancy and childhood. We have evaluated the relationship between thyroid function and OCs in preschool children.

Methods: Children from a general population birth cohort in Menorca (n = 259), Spain were assessed at the age of 4 years. Concentrations of THs (free T4 and total T3), thyrotropin (TSH) and a range of OCs were measured in peripheral blood.

Results: Blood levels of dichlorodiphenyl trichloroethane (p,p'-DDT), beta-hexachlorocylcohexane (beta-HCH), polychlorinated biphenyls (congeners PCB-138, PCB-153 and PCB-118) were related to lower total T3 levels (p<0.05). In addition, free T4 was inversely associated with PCB-118, while no relationship was found between TSH and any of the measured OCs.

Conclusions: This study suggests that even at background levels of exposure, OCs may affect the thyroid system, particularly total T3 levels.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child, Preschool
  • DDT / toxicity
  • Dichlorodiphenyl Dichloroethylene / toxicity
  • Environmental Exposure
  • Environmental Pollutants / toxicity*
  • Female
  • Hexachlorobenzene / toxicity
  • Hexachlorocyclohexane / toxicity
  • Humans
  • Hydrocarbons, Chlorinated / toxicity*
  • Infant
  • Infant, Newborn
  • Male
  • Multivariate Analysis
  • Polychlorinated Biphenyls / toxicity
  • Prospective Studies
  • Spain
  • Thyroid Diseases / blood
  • Thyroid Diseases / chemically induced*
  • Thyroid Diseases / physiopathology
  • Thyroid Gland / drug effects
  • Thyroid Gland / physiopathology
  • Thyroid Hormones / blood
  • Triiodothyronine / blood

Substances

  • Environmental Pollutants
  • Hydrocarbons, Chlorinated
  • Thyroid Hormones
  • Triiodothyronine
  • Dichlorodiphenyl Dichloroethylene
  • Hexachlorobenzene
  • Hexachlorocyclohexane
  • DDT
  • Polychlorinated Biphenyls
  • beta-hexachlorocyclohexane