Levels of urinary total and speciated arsenic in the US population: National Health and Nutrition Examination Survey 2003-2004

CALDWELL, KATHLEEN L.
JONES, ROBERT L.
VERDON, CARL P.
JARRETT, JEFFERY M.
CAUDILL, SAMUEL P.
OSTERLOH, JOHN D.

Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA

1 Address all correspondence to: Dr. Kathleen L. Caldwell, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford hwy, NE, Mailstop F-18, Atlanta, GA 30341, USA. Tel.: + 770 488 7990. Fax: + 770 488 4097.

E-mail: [email protected]

Received 5 February 2008; accepted 24 April 2008; published online 4 June 2008

Journal of Exposure Science and Environmental Epidemiology 19(1):p 59-68, January 2009.

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 (μg/l) and creatinine-corrected urinary arsenic (μg/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 μg/l). Monomethylarsonic acid was detected in 35% of the overall population. For all participants aged ≥6 years, dimethylarsinic acid (geometric mean of 3.71 μg/l) and arsenobetaine (geometric mean of 1.55 μg/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 ≥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 μg/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.

Journal of Exposure Science and Environmental Epidemiology (2009) 19, 59-68; doi:10.1038/jes.2008.32; published online 4 June 2008