Excretion of arsenic (As) in urine of children, 7-11 years, exposed to elevated levels of As in the city water supply in Hermosillo, Sonora, México.

Arsenic (As) is a common element in the environment with many industrial uses, but it also can be a contaminant in drinking water and present serious health concerns. Earlier studies on the quality of drinking water in the city of Hermosillo, Sonora, México, showed high levels of As (> 0.05 ppm) in water from wells located in the northern part of the city. Additionally a high positive correlation between the levels of Fluoride (F) and As in the same wells was found. Therefore, the objective of this study was to determine the excretion of As in children, 7-11 years of age, that had been exposed to elevated levels of As in their drinking water. Twenty-four-hour urine samples and a water sample taken directly in the home were collected from school age children living in two different areas with known high levels of As in their drinking water. A control group with normal levels of As in their water was also included. As was determined by an atomic absorption-hydride generator, verified with the use of NBS certified standards (SRM 1643a and SRM 2670). None of the water samples exceeded the limit established for drinking water; however, there was a significant difference between the intake of As and the As in drinking water among the three areas of the study. Average As in water was 0.009 +/- 0.002 and 0.030 +/- 0.011 micrograms/ml between the control and high areas. Intake (in micrograms/day) was 15 +/- 3 and 54 +/- 18. In the group consuming water with high levels of As, 65% of the children exceeded the recommended dose of < 1 micrograms/kg/day (EPA, 1988). Several children in this study also had high levels of As in their urine. Even though As levels in the drinking water are within the norms, it appears that children exposed to high levels of As in their drinking water may have a health risk.