Bioavailability of arsenic in soil: pilot study results and design considerations.

Bioavailability of arsenic (As) from ingested soil is estimated in a two-period experimental study involving 11 subjects/period. In the first period, a 7-day mass-balance study measured As in food/beverages, urine, and stool to estimate bioavailability of As in food and beverages. Food/beverage As bioavailability (percentage ingested that is not in stool samples) is estimated as 91.