Bioavailability of Arsenic in Soil and House Dust Impacted by Smelter Activities Following Oral Administration in Cynomolgus Monkeys

This study was conducted to determine the extent of arsenic(As) absorption from soil and house dust impacted by smelteractivities near Anaconda, Montana. Female cynomolgus monkeyswere given a single oral administration via gelatin capsulesof soil (0.62 mg As/kg body wt) or house dust (0.26 mg As/kgbody wt), or soluble sodium arsenate by the gavage or intravenousroute of administration (0.62 mg As/kg body wt) in a crossoverdesign with a minimum washout period of 14 days. Urine, feces,and cage rinse were collected at 24-hr intervals for 168 hr.Blood was collected at specified time points and area underthe curves (AUCs) was determined. Arsenic concentrations forthe first 120 hr, representing elimination of greater than 94%of the total administered dose for the three oral treatmentgroups, were <0.02 1 to 4.68 zg/ml for the urine and <0.24to 31.1 µg/g for the feces. In general, peak concentrationsof As in the urine and feces were obtained during the collectionintervals of 0–24 and 24–72 hr, respectively. Themain pathway for excretion of As for the intravenous and gavagegroups was in the urine, whereas for the soil and dust groups,it was in the feces. Mean absolute percentage bioavailabilityvalues based on urinary excretion data were 68, 19, and 14%for the gavage, house dust, and soil treatments, respectively,after normal ization of the intravenous As recovery data to100%. Correspond ing absolute bioavailability values based onblood were 91, 10, and 11%. The bioavailabiity of soil and housedust As relative to soluble As (by gavage) was between 10 and30%, depending upon whether urinary or blood values were used.These findings suggest that risks associated with the ingestionof As in soil or dust will be reduced compared to ingestionof comparable quantities of As in drinking water.