Number of persistent organic pollutants (POPs) detected at high concentrations in the U.S. population (NHANES 2003-2004)
METHODS: In each individual ≥20 years old, we computed the number of POPs whose serum concentrations were equal to or greater than a selected cutoff point. We analyzed the concentrations of 91 compounds. Different POPs were studied in three different samples of individuals.
RESULTS: When we considered compounds detected in ≥85% of individuals and the cutoff point for ‘high concentration’ was set at percentile 90 (P90) of the distribution of each compound, 26.1% of participants in the first sample, 43.5% of participants of the second sample and 48.9% of participants of the third sample had ≥1 of compounds at ‘high concentrations’. 14% of members of the latter sample had ≥8 POPs each at ‘high concentrations’. No differences were found by gender. With less restrictive criteria (e.g., compounds detected in ≥75% of participants), more than 50% of individuals had ≥1 compounds at concentrations ≥P90. We also analyzed the total toxic equivalency (TEQ) for dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls (26 compounds analyzed in the same sample of individuals). 19.6% of participants had ≥1 compounds at concentrations ≥P90 and [TEQ] ≥P75.
CONCLUSIONS: More than 25% of the US population may have ≥1 compounds at ‘high concentrations’. The indicators showed the number of subjects exposed to a greater amount of toxic compounds considering both the number of compounds detected per person and the individual concentration / TEQ of each compound. The same methodology can be applied in other population surveys and etiological studies.