Uranium in Drinking Water: Renal Effects of Long-Term Ingestion by an Aboriginal Community

ABSTRACT

The authors conducted a study of an aboriginal community to determine if kidney func-tion had been affected by the chronic ingestion of uranium in drinking water from the community's drilled wells. Uranium concentrations in drinking water varied from < 1 to 845 ppb. This nonin-vasive study relied on the measurement of a combination of urinary indicators of kidney function and markers for cell toxicity. In all, 54 individuals (12–73 years old) participated in the study. Correlation of uranium excreted in urine with bio-indicators at p ≤.05 indicated interference with the kidney's reabsorptive function. Because of the community's concerns regarding cancer incidence, the authors also calculated cumulative radiation doses using uranium intake in drinking water over the preceding 15-year period. The highest total uranium intake over this period was 1,761 mg. The risk of cancer from the highest dose, 2.1 mSv, is 13 in 100,000, which would be difficult to detect in the community studied (population size = 1,480). This study indicates that at the observed levels of uranium intake, chemical toxicity would be a greater health concern than would radiation dose.

KEYWORDS:

• chemical toxicity
• chronic ingestion
• environmental exposures
• kidney function in humans
• radiation dose
• uranium in drinking water

Acknowledgments

The authors are most grateful to Ms Eliza McGregor and Ms Cheryl Moore for their assistance in recruiting volunteers and their perseverance in the collection of information. They also thank Dr Harold Schwartz for pro-viding information regarding uranium concentrations in the community's drinking water and quality assurance for the uranium in water measure-ments. The authors appreciate Mr Jeff Moore's arranging for financial as-sistance from the Medical Services Branch to cover incremental expenses incurred during the study. They also thank Dr Sabit Cakmak, Mr Richard Charron, and Dr Gary H. Kramer for reviewing the manuscript and offering valuable comments.

Notes

^aData point not used: No information on uranium concentration in water for major part of 2.8 year period.

^bResults not reported were below the method detection limit.

^aData point not used: No information on uranium concentration in water for major part of 2.8 year period.

^bResults not reported were below the method detection limit.

^aOne volunteer reported zero tap water intake in his questionnaire. This information was used to calculate all exposure indicators for this participant.

*Statistically significant difference at p ≤ .05.

^aGender dependent (unadjusted data).

^bGender dependent (adjusted data).