| Bone as a Possible Target of Chemical Toxicity of Natural Uranium in Drinking Water Päivi Kurttio,1 Hannu Komulainen,2 Aila Leino,3 Laina Salonen,1 Anssi Auvinen,4 and Heikki Saha5 1STUK-Radiation and Nuclear Safety Authority, Research and Environmental Surveillance, Helsinki, Finland; 2Division of Environmental Health, National Public Health Institute, Kuopio, Finland; 3Department of Clinical Chemistry, Turku University Hospital, Turku, Finland; 4School of Public Health, University of Tampere, Tampere, Finland; 5Department of Internal Medicine, Tampere University Hospital, Tampere, Finland
Abstract
Uranium accumulates in bone, affects bone metabolism in laboratory animals, and when ingested in drinking water increases urinary excretion of calcium and phosphate, important components in the bone structure. However, little is known about bone effects of ingested natural uranium in humans. We studied 146 men and 142 women 26-83 years of age who for an average of 13 years had used drinking water originating from wells drilled in bedrock, in areas with naturally high uranium content. Biochemical indicators of bone formation were serum osteocalcin and amino-terminal propeptide of type I procollagen, and a marker for bone resorption was serum type I collagen carboxy-terminal telopeptide (CTx) . The primary measure of uranium exposure was uranium concentration in drinking water, with additional information on uranium intake and uranium concentration in urine. The data were analyzed separately for men and women with robust regression (which suppresses contributions of potential influential observations) models with adjustment for age, smoking, and estrogen use. The median uranium concentration in drinking water was 27 µg/L (interquartile range, 6-116 µg/L) . The median of daily uranium intake was 36 µg (7-207 µg) and of cumulative intake 0.12 g (0.02-0.66 g) . There was some suggestion that elevation of CTx (p = 0.05) as well as osteocalcin (p = 0.19) could be associated with increased uranium exposure (uranium in water and intakes) in men, but no similar relationship was found in women. Accordingly, bone may be a target of chemical toxicity of uranium in humans, and more detailed evaluation of bone effects of natural uranium is warranted. Key words: bone, bone turnover markers, CTx, drinking water, osteocalcin, P1NP, uranium. Environ Health Perspect 113:68-72 (2005) . doi:10.1289/ehp.7475 available via http://dx.doi.org/ [Online 30 September 2004]
Address correspondence to P. Kurttio, STUK-Radiation and Nuclear Safety Authority, Research and Environmental Surveillance, Laippatie 4, FIN-00881 Helsinki, Finland. Telephone: 358-9-75988554. Fax: 358-9-75988464. E-mail: paivi.kurttio@stuk.fi We thank D. Pawel, U.S. Environmental Protection Agency, for useful discussions on statistical analyses of the data, and the study persons and laboratories in the primary health centers for participating in the study. The Ministry of Social Affairs and Health of Finland and Medical Research Fund of Tampere University Hospital financially supported this study. The authors declare they have no competing financial interests. Received 5 August 2004 ; accepted 30 September 2004.
The full version of this article is available for free in HTML or PDF formats. |
