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This study wasconducted to investigate whether drinking water is a significant source of intake ofperchlorate, nitrate and iodide. The National Health and Nutrition Examination Survey(NHANES) conducted by the National Center for Health Statistics of the Centers forDisease Control and Prevention collected 3,264 tap water samples from households from30 selected locations across the United States during the years 2005-2006. The tap watersamples were assayed for perchlorate, nitrate and iodide using ion chromatographycoupled with electrospray ionization-tandem mass spectrometry. The median perchlorate,nitrate and iodide levels measured in tap water were 1.17, 1040 and 5.20 g/Lrespectively. Perchlorate levels found were below the U. S. EnvironmentalProtection Agency (USEPA) drinking water equivalent level (DWEL) for perchlorate(24.5g/L). Nitrate levels of 0.4% of total samples exceeded the USEPA MCL of 44.3mg/L. Significant correlations were found between iodide and nitrate levels (r=0.17,p0.0001) and perchlorate and nitrate levels (r=0.25, p0.0001). NHANES 2005-2006estimated the median perchlorate and nitrate intake through drinking water as 0.005 and7.62 g/kg-day respectively for the U.S. population. The perchlorate exposure doseattributable to drinking water estimated for NHANES 2005-2006 is relatively small(9.4%) compared to the total perchlorate exposure dose previously characterized for theU.S. population (NHANES 2001-2002). This study also shows that drinking water is not asignificant source of intake of iodide (0.13 g/kg-day) which is an essential humannutrient. Includes abstract only.

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Edition: Vol. - No. Published: 11/01/2009 Number of Pages: 1File Size: 1 file