Current Estimates of Population Serum PCDD, PCDF, and Dioxin-like PCB Levels in the United States

ISEE-1210

Background:

Environmental emissions of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) have been decreasing over the past three decades. However, population serum concentrations of these compounds continue to be monitored due to their environmental persistence and bioaccumulation. Three recent studies of adults in the United States were compared to identify current population concentrations of PCDDs, PCDFs, and PCBs.

Methods:

Data are taken from the 2004-2005 University of Michigan Dioxin Exposure Study (UMDES) which analyzed serum from 946 Michigan subjects including 251 control subjects; the Agency for Toxic Substances and Disease Registry's (ATSDR) 2001 study of 415 subjects from two parishes in Louisiana; and the 2001-2002 National Health and Nutrition Examination Survey (NHANES) of the United States which included serum concentrations from 1081 adults from multiple states.

Results and Discussion:

Adult concentrations of total PCDDs, PCDFs and dioxin-like PCBs calculated using the World Health Organization's 1998 toxic equivalency system range from 5-238 parts per trillion (ppt) for the UMDES sample (29 congeners), from 3-166 ppt for the ATSDR sample (23 congeners), and from 8-208 ppt for the NHANES sample (26 congeners). Analyses suggest that age-stratified median and 95th percentile levels of total serum PCDDs, PCDFs and PCBs are also similar across the nation, regardless of the location of the population sampled. The concentrations of total serum dioxins, furans and PCBs have decreased in comparison to historical levels from the United States. Additional serum concentration data from the three studies and references will be provided.