Because of health concerns surrounding in utero and neonatal exposure to perchlorate, we developed a method for analyzing perchlorate in the dried blood spots (DBS) of newborns. Ion chromatography was interfaced with electrospray ionization tandem mass spectrometry to measure blood perchlorate levels in DBS samples as low as 0.10 ng/mL. Measurement of perchlorate in DBS indicated good precision (relative standard deviations ranging from 5.8% to 16.2%) and accuracy (% difference values ranging from -11.3% to -12.1%). Perchlorate was detectable in 100% of the DBS collected from 100 newborns. These samples had a median blank-adjusted concentration of 1.88 ng/mL. Such data support the utility of this method to quantify perchlorate levels in DBS samples. Applying this method to analyze neonatal DBS will improve perchlorate exposure assessments of this susceptible population.
Perchlorate is a naturally occurring inorganic anion used as a component of solid rocket fuel, explosives, and pyrotechnics. Sufficiently high perchlorate intakes can modify thyroid function by competitively inhibiting iodide uptake in adults; however little is known about perchlorate exposure and health effects in infants. Food intake models predict that infants have higher perchlorate exposure doses than adults. For this reason, we measured perchlorate and related anions (nitrate, thiocyanate, and iodide) in 206 urine samples from 92 infants ages 1–377 days and calculated perchlorate intake dose for this population of infants. The median estimated exposure dose for this population of infants was 0.160 μg/kg/day. Of the 205 individual dose estimates, 9% exceeded the reference dose of 0.7 μg/kg/day; 6% of infants providing multiple samples had multiple perchlorate dose estimates above the reference dose. Estimated exposure dose differed by feeding method: breast-fed infants had a higher perchlorate exposure dose (geometric mean 0.220 μg/kg/day) than infants consuming cow milk-based formula (geometric mean 0.103 μg/kg/day, p<0.0001) or soy-based formula (geometric mean 0.027 μg/kg/day, p<0.0001), consistent with dose estimates based on dietary intake data. The ability of perchlorate to block adequate iodide uptake by the thyroid may have been reduced by the iodine-sufficient status of the infants studied (median urinary iodide 125 μg/L). Further research is needed to see whether these perchlorate intake doses lead to any health effects.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.