Dioxins and dibenzofurans in adipose tissue of the general US population and selected subpopulations.

OBJECTIVES: The Environmental Protection Agency's National Human Adipose Tissue Survey (NHATS) was conducted in fiscal year (FY) 1987 to (1) estimate average concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in the adipose tissue of humans in the US population, (2) identify differences in average concentrations among subpopulations, and (3) compare average concentrations with those from the FY 1982 NHATS: METHODS: Population estimates of the average levels of PCDDs and PCDFs were established on the basis of 865 human adipose tissue specimens collected in FY 1987. Average levels among subpopulations were compared. RESULTS: The average concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin in the adipose tissue of the US population was 5.38 pg/g, increasing from 1.98 pg/g in children under 14 years of age to 9.40 pg/g in adults over 45. The effect of age was significant for nine compounds. Regional differences in the levels of 2,3,4,7,8-pentachlorinated dibenzofurans were statistically significant, but there were no significant differences associated with sex or race. CONCLUSIONS: The survey provides a baseline of average levels of PCDDs and PCDFs in the adipose tissue of humans in the US population.