This study was
conducted to investigate whether drinking water is a significant source of intake of
perchlorate, nitrate and iodide. The National Health and Nutrition Examination Survey
(NHANES) conducted by the National Center for Health Statistics of the Centers for
Disease Control and Prevention collected 3,264 tap water samples from households from
30 selected locations across the United States during the years 2005-2006. The tap water
samples were assayed for perchlorate, nitrate and iodide using ion chromatography
coupled with electrospray ionization-tandem mass spectrometry. The median perchlorate,
nitrate and iodide levels measured in tap water were 1.17, 1040 and 5.20 µg/L
respectively. Perchlorate levels found were below the U. S. Environmental
Protection Agency (USEPA) drinking water equivalent level (DWEL) for perchlorate
(24.5µg/L). Nitrate levels of 0.4% of total samples exceeded the USEPA MCL of 44.3
mg/L. Significant correlations were found between iodide and nitrate levels (r=0.17,
p<0.0001) and perchlorate and nitrate levels (r=0.25, p<0.0001). NHANES 2005-2006
estimated the median perchlorate and nitrate intake through drinking water as 0.005 and
7.62 µg/kg-day respectively for the U.S. population. The perchlorate exposure dose
attributable to drinking water estimated for NHANES 2005-2006 is relatively small
(9.4%) compared to the total perchlorate exposure dose previously characterized for the
U.S. population (NHANES 2001-2002). This study also shows that drinking water is not a
significant source of intake of iodide (0.13 µg/kg-day) which is an essential human
nutrient. Includes abstract only.
| Edition : | Vol. - No. |
| Number of Pages : | 1 |
| Published : | 11/01/2009 |
