Levels of urinary total and speciated arsenic in the US population: National Health and Nutrition Examination Survey 2003-2004.
OBJECTIVE
To provide levels of total and speciated urinary arsenic in a representative sample of the US population.


METHODS
For the first time, total arsenic and seven inorganic and organic arsenic species were measured in the urine of participants (n=2557) for the 2003-2004 National Health and Nutrition Examination Survey (NHANES). Data were compiled as geometric means and selected percentiles of urinary arsenic concentrations (microg/l) and creatinine-corrected urinary arsenic (microg/g creatinine) for total arsenic, dimethylarsinic acid, arsenobetaine, and a sum of the inorganic related species.


RESULTS
Arsenic acid, arsenous acid, arsenocholine, and trimethylarsine oxide were detected in 7.6%, 4.6%, 1.8%, and 0.3% of the participants, respectively (the limits of detection of 0.6-1.2 microg/l). Monomethylarsonic acid was detected in 35% of the overall population. For all participants aged > or =6 years, dimethylarsinic acid (geometric mean of 3.71 microg/l) and arsenobetaine (geometric mean of 1.55 microg/l) had the greatest contribution to the total urinary arsenic levels. A relatively greater percentage contribution from arsenobetaine is seen at higher total urinary arsenic levels and from dimethylarsinic acid at lower total urinary arsenic levels. For all participants aged > or =6 years, the 95th percentiles for total urinary arsenic and the sum of inorganic-related arsenic (arsenic acid, arsenous acid, dimethylarsinic acid, and monomethylarsonic acid) were 65.4 and 18.9 microg/l, respectively. For total arsenic and dimethylarsinic acid, covariate-adjusted geometric means demonstrated several slight differences due to age, gender, and race/ethnicity.


CONCLUSIONS
The data reflect relative background contributions of inorganic and seafood-related arsenic exposures in the US population. Arsenobetaine and dimethylarsinic acid are the major arsenic species present with arsenobetaine, accounting for a greater proportion of total arsenic as total arsenic levels increase.
Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. kcaldwell@cdc.gov
Kathleen L
KL
Caldwell
Robert L
RL
Jones
Carl P
CP
Verdon
Jeffery M
JM
Jarrett
Samuel P
SP
Caudill
John D
JD
Osterloh
D000293:Adolescent; D000328:Adult; D001151:Arsenic / Q000652:urine*; D001152:Arsenicals / Q000652:urine*; D002487:Centers for Disease Control and Prevention, U.S.; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D006801:Humans; D009749:Nutrition Surveys; D011153:Population; D011634:Public Health; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
D001152:Arsenicals; D001151:Arsenic