Excretion of arsenic in urine as a function of exposure to arsenic in drinking water.

Abstract

Urinary arsenic (As) concentrations were evaluated as a biomarker of exposure in a U.S. population chronically exposed to inorganic As (InAs) in their ddnking water. Ninety-si individuals who consumed drinking water with As concentrations of 8-620 P/L provided first moring urine voids for up to 5 consecutive days. The study population was 56% male, and 44% was younger than 18 year of age. On one day of the study period, all voided urines were collected over a 24-hr period. Arsenic intake from drnking water was estimated from daily food diaries.Comparison between the concentration of As in individual urine voids with that in the 24-hr urine collection indicated that the. ncentration of As in urine was sble throughout the day.Comparison of the concentration ofAs in each first morning urine void over the 5-day studyod indicated that there was little day-to-day variation in the co on of.As in urine. The concentration of As in drinking water was a better predictor of the concenton of As in urine than was the estimated intake of from driking water. little information on intra-or interindividual variation in the output of As in urine independent of dose. In particular, there is little information on the extent of As exposure in U.S. populations that consume drinking water that contains As. The research described in this paper provides novel information on the pattern and extent of urinary As excretion in a U.S. population exposed to As in drinking water.In the present study, we evaluated the excretion of As in urine in a Millard County, Utah, population that is chronically exposed to InAs from drinking water. We found that the concentration ofAs excreted in urine was highly correlated with the concentration of InAs in the drinking water supply and the concentration of As in urine was remarkably stable throughout a single day and over a 5-day study period. These findings suggest that the analysis of a small number of urine samples may be adequate to estimate an individual's exposure to InAs from drinking water and that the determination of the concentration of InAs in a drinking water supply may be a useful surrogate for estimating exposure to this metalloid. MethodsSite selection. Study subjects were recruited from long-term residents of Millard County, Utah. The primary industry in this region is agricultural, and surface water is only used for crop irrigation. Drinking water supplies are obtained from public and private wells. The source of the InAs in drinking water is As that occurs naturally in the soil and rock strata. The likely sources of soil As are several extinct volcanos within the study area. The state of Utah has measured InAs concentrations in the wells used for drinking water and livestock in this area for more than 30 years.The InAs concentrations of wells in this area have been stable for many years and range from 2 to over 600 pg/L (16).Subject selection. The study population included mostly members of the Church of Jesus Christ of Latter-Day Saints. Possible confounding factors such as smoking, alco...

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Arsenic methylation and lung and bladder cancer in a case-control study in northern Chile

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Biomarkers of Exposure: A Case Study with Inorganic Arsenic

“…Collection of urine for 24 hr can be difficult, because of quality assurance logistics, particularly if a large number of samples are to be collected. Urinary arsenic does not appear to vary over time, so spot collection or first morning void may be used (Calderon et al 1999; Hewitt et al 1995). In addition, intraindividual variation of iAs metabolism and its urinary excretion was low over a 5-day period (Concha et al 2002).…”