Title: EXPOSURE TO ARSENIC FROM CROPS IRRIGATED WITH CONTAMINATED WATER
Abstract: Introduction The potential exposure to arsenic through ingestion of crops irrigated with arsenic contaminated water has been of recent concern in Bangladesh. There is international literature reporting arsenic levels in various food crops, but there is no literature examining exposure from ingestion of crops irrigated with contaminated water. The aim of our study was to determine whether crops irrigated with arsenic contaminated water were a source of exposure to arsenic in humans. Methods In May 2000, we conducted an intervention trial in Jessor District of Bangladesh. The village of Sardar Bagh Danga was chosen as the study village based on field kit testing of irrigation water, reporting arsenic levels between 100 and 500 mg/L. The village was mapped and a random sample of 63 people meeting eligibility criteria was recruited to the study. The intervention group was provided food purchased from a village where irrigation water was found to contain < 10mg/L of arsenic, while the control group was provided food purchased from the study area. Food was provided for the entire household for a period of 10 days. Pre and post intervention urine samples were collected in triplicate for arsenic speciation, and arsenic concentrations compared using analysis of variance analysis of log transformed data. Raw and cooked food samples were also collected for arsenic speciation. Results The median urinary total arsenic concentrations for the intervention group (n = 30) changed from 139.25 (range 35.3 to 736.5) to 140.00 (range 20.75 to 810) following intervention, and for the control group (n = 30) from 129.15 mg/L (range 21.5 to 555.56) to 146.00 mg/L (range 21.25 to 840). Median total inorganic arsenic concentrations for the intervention and control groups changed from 39.93 mg/L (range 3.53 to 193.53) and 42 mg/L (range 3.33 to 232.73) at baseline, to 35.73 mg/L (range 9 to 205.27) and 36.07 mg/L (range 5.07 to 174.47) respectively, following intervention. The changes in urinary arsenic concentrations following intervention were not significantly different for the two groups. Arsenic concentrations in selected raw or cooked food from the low contamination area did not show an obvious trend of containing less arsenic compared to samples from the high contamination area. Conclusion Provision of food purchased from an area with low arsenic content in irrigation water, to people living in an area with high arsenic content in irrigation water, did not significantly alter the urinary arsenic concentration. There are several possible explanations for this null finding. Further investigation is required of arsenic content in food crops grown in high and low contamination areas.