Arsenic contamination of Ronphibun residents associated with uses of arsenic-contaminated shallow-well water other than drinking

Abstract

High levels of urinary arsenic have been reported among residents of an area of southern Thailand where many households have shallow wells heavily contaminated with arsenic. However, the finding that very few of the residents in this area have used contaminated shallow-well water for drinking or cooking in the last 10 years prompted this investigation. The aim was to identify the uses of shallow-well water by adult residents that were related to a positive association between shallow-well water and urinary arsenic levels. Information on shallow-well water use for all personal and domestic purposes was obtained and arsenic levels of household shallow-well water and urine (after refraining from seafood for 2 days) were measured. Urinary and shallow-well water arsenic levels were strongly positively associated among residents who regularly used shallow-well water for bathing (including washing face, hair, hands and feet) but not among residents regularly using arsenic-safe water for bathing or regularly using shallow-well water for other purposes, such as brushing teeth, domestic cleaning or washing food and utensils. The findings suggest that appreciable transdermal absorption of arsenic is possible and that successful abatement of human contamination with arsenic may require the provision of arsenic-safe water, not only for consumption but also for personal hygiene purposes.

Keywords:

• Arsenic contamination
• urinary arsenic
• well water
• water use
• bathing

Acknowledgments

The authors express the sincerest appreciation to the residents of Ronphibun sub-district for their cooperation, to the staff of Ronphibun Hospital, the Village Health Volunteers and the staff of the National Institute of Health, Department of Medical Sciences, who all helped in data and specimen collection, and to the students of the School of Environmental Studies, Jadavpur University, who analyzed arsenic in urine and water specimens. This study was supported by the Graduate School, Prince of Songkla University. The Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, is partially supported by the Thailand Research Fund.

Notes

¹Twelve subjects reported never brushing their teeth.

²Total numbers of subjects performing these activities by themselves: washing food 177, washing utensils 176, washing clothes 185, cleaning house 128.

³Forty three subjects reported not using water for cleaning the house.