Perchlorate exposure of the US Population, 2001-2002. J Exp Sci Environ Epidemiol

Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA.
Journal of Exposure Science and Environmental Epidemiology (Impact Factor: 3.19). 08/2007; 17(4):400-7. DOI: 10.1038/sj.jes.7500535
Source: PubMed


Perchlorate is commonly found in the environment and can impair thyroid function at pharmacological doses. As a result of the potential for widespread human exposure to this biologically active chemical, we assessed perchlorate exposure in a nationally representative population of 2,820 US residents, ages 6 years and older, during 2001 and 2002 as part of the National Health and Nutrition Examination Survey (NHANES). We found detectable levels of perchlorate (>0.05 microg/l) in all 2,820 urine samples tested, indicating widespread human exposure to perchlorate. Urinary perchlorate levels were distributed in a log normal fashion with a median of 3.6 microg/l (3.38 microg/g creatinine) and a 95th percentile of 14 microg/l (12.7 microg/g creatinine). When geometric means of urinary perchlorate levels were adjusted for age, fasting, sex and race-ethnicity, we found significantly higher levels of urinary perchlorate in children compared with adolescents and adults. We estimated total daily perchlorate dose for each adult (ages 20 years and older), based on urinary perchlorate, urinary creatinine concentration and physiological parameters predictive of creatinine excretion rate. The 95th percentile of the distribution of estimated daily perchlorate doses in the adult population was 0.234 microg/kg-day [CI 0.202-0.268 microg/kg-day] and is below the EPA reference dose (0.7 microg/kg-day), a dose estimated to be without appreciable risk of adverse effects during a lifetime of exposure. These data provide the first population-based assessment of the magnitude and prevalence of perchlorate exposure in the US.

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Available from: Benjamin C Blount, Oct 03, 2014
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    • "We found lower total blood mercury (Hg) in low-income, non-Hispanic whites and Mexican Americans, consistent with studies reporting lower Hg levels among Mexican Americans [50,51] and inverse associations between Hg and income [10]. We found lower urinary perchlorate in non-Hispanic blacks (low- and high-income) versus high-income, non-Hispanic whites in NHANES 2003–2004, similar to Blount et al.’s [52] NHANES 2001–2002 finding for men. We found lower serum perfluoroctanoic acid (PFOA) in the low-income minority subgroups and lower perfluorooctane sulfonic acid (PFOS) among low-income Mexican Americans, consistent with NHANES 1999–2008 findings of lower PFOA and PFOS in Mexican Americans and lower PFOA in blacks [53], and with NHANES 2003–2008 findings of negative associations between income and PFOA and PFOS levels [10,54]. "
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    ABSTRACT: Environmental biomonitoring data provide one way to examine race/ethnicity and income-related exposure disparity and identify potential environmental justice concerns. We screened U.S. National Health and Nutrition Examination Survey (NHANES) 2001-2008 biomonitoring data for 228 chemicals for race/ethnicity and income-related disparity. We defined six subgroups by race/ethnicity--Mexican American, non-Hispanic black, non-Hispanic white--and income--Low Income: poverty income ratio (PIR) <2, High Income: PIR >= 2. We assessed disparity by comparing the central tendency (geometric mean ratio [GMR]) of the biomonitoring concentration of each subgroup to that of the reference subgroup (non-Hispanic white/High Income), adjusting for multiple comparisons using the Holm-Bonferroni procedure. There were sufficient data to estimate at least one GMR for 108 chemicals; 37 had at least one GMR statistically different from one. There was evidence of potential environmental justice concern (GMR significantly >1) for 12 chemicals: cotinine; antimony; lead; thallium; 2,4- and 2,5-dichlorophenol; p,p'-dichlorodiphenyldichloroethylene; methyl and propyl paraben; and mono-ethyl, mono-isobutyl, and mono-n-butyl phthalate. There was also evidence of GMR significantly <1 for 25 chemicals (of which 17 were polychlorinated biphenyls). Although many of our results were consistent with the U.S. literature, findings relevant to environmental justice were novel for dichlorophenols and some metals.
    Environmental Health 12/2013; 12(1):114. DOI:10.1186/1476-069X-12-114 · 3.37 Impact Factor
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    • "It is primarily synthesized for use as an oxidant in solid rocket propellant. Perchlorate has been detected in food and drinking water from various regions of the U.S. [1]–[3], and human exposure to perchlorate is widespread in the U.S. population [4]. At high doses (mg/kg of body weight/day), perchlorate can affect the ability of the thyroid to absorb iodine and can limit the production of thyroid hormones, which are important for proper development in children [5]. "
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    ABSTRACT: Exposure to perchlorate is ubiquitous in the United States and has been found to be widespread in food and drinking water. People living in the lower Colorado River region may have perchlorate exposure because of perchlorate in ground water and locally-grown produce. Relatively high doses of perchlorate can inhibit iodine uptake and impair thyroid function, and thus could impair neurological development in utero. We examined human exposures to perchlorate in the Imperial Valley among individuals consuming locally grown produce and compared perchlorate exposure doses to state and federal reference doses. We collected 24-hour urine specimen from a convenience sample of 31 individuals and measured urinary excretion rates of perchlorate, thiocyanate, nitrate, and iodide. In addition, drinking water and local produce were also sampled for perchlorate. All but two of the water samples tested negative for perchlorate. Perchlorate levels in 79 produce samples ranged from non-detect to 1816 ppb. Estimated perchlorate doses ranged from 0.02 to 0.51 µg/kg of body weight/day. Perchlorate dose increased with the number of servings of dairy products consumed and with estimated perchlorate levels in produce consumed. The geometric mean perchlorate dose was 70% higher than for the NHANES reference population. Our sample of 31 Imperial Valley residents had higher perchlorate dose levels compared with national reference ranges. Although none of our exposure estimates exceeded the U. S. EPA reference dose, three participants exceeded the acceptable daily dose as defined by bench mark dose methods used by the California Office of Environmental Health Hazard Assessment.
    PLoS ONE 03/2011; 6(3):e17015. DOI:10.1371/journal.pone.0017015 · 3.23 Impact Factor
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