Academic journal article Environmental Health Perspectives

Assessing the Measurement Precision of Various Arsenic Forms and Arsenic Exposure in the National Human Exposure Assessment Survey (NHEXAS)

Academic journal article Environmental Health Perspectives

Assessing the Measurement Precision of Various Arsenic Forms and Arsenic Exposure in the National Human Exposure Assessment Survey (NHEXAS)

Article excerpt

Archived samples collected from 1995 to 1997 in the National Human Exposure Assessment Survey (NHEXAS) in U.S. Environmental Protection Agency Region 5 (R5) and the Children's Study (CS) in Minnesota were analyzed for total arsenic, arsenate [As(V)], arsenite, dimethyl arsenic acid (DMA), monomethyl arsenic acid (MMA), arsenobetaine (AsB), and arsenocholine. Samples for the CS included drinking water, urine, hair, and dust; both studies included food (duplicate plate, composited 4-day food samples from participants). Except for AsB and As(V), the levels for As species measured in the food and drinking water samples were very low or nonexistent. The analytical methods used for measuring As species were sensitive to < 1 ppb. During the analysis of food and drinking water samples, chromatographic peaks appeared that contained As, but they did not correspond to those being quantified. Thus, in some samples, the sum of the individual As species levels was less than the total As level measured because the unknown forms of As were not quantified. On the other hand, total As was detectable in almost all samples (> 90%) except for hair (47%), indicating that the analytical method was sufficiently sensitive. Population distributions of As concentrations measured in drinking water, food (duplicate plate), dust, urine, and hair were estimated. Exposures to total As in food for children in the CS were about twice as high as in the general R5 population (medians of 17.5 ppb and 7.72 ppb, respectively). In addition, AsB was the most frequently detected form of AS in food eaten by the participants, while As(V) was only rarely detected. Thus, the predominant dietary exposure was from an organic form of As. The major form of As in drinking water was As(V). Spearman (rank) correlations and Pearson (log-concentration scale) correlations between the biomarkers (urine, hair) and the other measures (food, drinking water, dust) and urine versus hair were performed. In the NHEXAS CS, total As and AsB in the food eaten were significantly correlated with their levels in urine. Also, levels of As(V) in drinking water correlated with DMA and MMA in urine. Arsenic levels in dust did not show a relationship with urine or hair levels, and no relationship was observed for food, drinking water, and dust with hair. Urine samples were collected on days 3, 5, and 7 of participants' monitoring periods. Total As levels in urine were significantly associated across the three pairwise combinations--i.e., day 3 versus day 5, day 3 versus day 7, and day 5 versus day 7. Because the half-life of As in the body is approximately 3 days, this suggests that some exposure occurred continually from day to day. This trend was also observed for AsB, suggesting that food is primarily responsible for the continual exposure. DMA and MMA in urine were also significantly correlated but not in all combinations. Key words: arsenic species, children, drinking water, food, human exposure, National Human Exposure Assessment Survey, NHEXAS, population study, urine. doi:10.1289/ehp.8104 available via http://dx.doi.org/[Online 13 October 2005]

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The adverse health effects of exposure to high arsenic levels, including a deterioration of skin on the hands (Dibner 1958), were recognized as early as 1556. The effects of exposure to As were reported four centuries later by Hutchison, who described skin carcinoma in patients treated with arsenical-based compounds (Hunter 1957).

Subsequently, inhalation of inorganic As was found to produce lung cancer [International Agency for Research on Cancer (IARC) 1980], and studies in the 20th century have shown increased risks of skin, liver, lung, bladder, and kidney cancers in Taiwanese, Mexican, Indian, German, Argentinean, and Chilean populations [Agency for Toxic Substances and Disease Registry (ATSDR) 1989; Bergoglio 1964; Biagini et al. 1978; Cebrian et al. 1983; Chakraborty and Saha 1987; Chen et al. 1985, 1986, 1988a, 1994; Chen and Wang 1990; Chiang et al. …

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