Environmental chemicals in pregnant women in the United States: NHANES 2003-2004.
Level 4 - case-series / case-control
Cross-sectional biomonitoring analysis of national survey data
PubMed 21233055 · doi:10.1289/ehp.1002727
What was done
Researchers analyzed NHANES 2003–2004 biomonitoring data to assess individual and multiple chemical exposures in subsamples of 268 pregnant women representative of the U.S. population. They evaluated 163 chemical analytes across 12 chemical classes, including polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), organochlorine pesticides, and phthalates. Detection counts within and across classes were calculated, and least-squares geometric mean chemical concentrations were compared between pregnant and nonpregnant women after adjusting for demographic and physiological covariates.
What was found
The percentage of pregnant women with detectable levels of an individual chemical ranged from 0% to 100%. Specific analytes among PCBs, organochlorine pesticides, PFCs, phenols, PBDEs, phthalates, polycyclic aromatic hydrocarbons (PAHs), and perchlorate were detected in 99% to 100% of pregnant women. By class, the median number of detected chemicals ranged from 4 of 12 PFCs to 9 of 13 phthalates; across multiple chemical classes, the median detected ranged from 8 of 17 to 50 of 71 analytes. Overall, chemical levels in pregnant women were similar to or lower than those in nonpregnant women, though adjusting for covariates tended to increase estimated levels in pregnant women relative to nonpregnant women.
Why it matters
This study provides national baseline evidence that pregnant women in the United States are routinely exposed to complex mixtures of industrial and environmental toxicants simultaneously.
Limits
The cross-sectional design captures exposure at a single time point and cannot determine specific exposure sources or long-term trends. The sample size was relatively small (268 pregnant women evaluated in subsamples), the data reflect exposures from 2003–2004, and the study did not measure clinical pregnancy outcomes or direct fetal health effects.
Cited by
- supports CDC NHANES biomonitoring data detected phthalates in nearly 100% of a representative sample of the US population.