Urinary Disease Morbidity and Mortality in a Population Environmentally Exposed to Cadmium and Other Nephrotoxic Metals

Abstract

ISEE-0675 Background and Objectives: Exposure to cadmium and other nephrotoxic metals may cause damage to the urinary system. Food is the main source of cadmium exposure in non-smokers. A lead/zinc smelter in Avonmouth (southwest England) was a major source of environmental cadmium for over 70 years. Emissions from the site may have led to increased cadmium exposure in the local population through inhalation of contaminated air and the ingestion of home-grown vegetables and house dust. A previous study carried out in the area showed a positive dose-response relationship between urinary cadmium and a biomarker of kidney tubular damage. Methods: A validated air dispersion model was used to define high, medium and low exposure groups within the vicinity of the smelter. Routinely collected data were used to assess non-malignant urinary disease morbidity and mortality using the southwest England region as the reference. Relative risks for sub-groups of urinary disease were also calculated. Analyses for men and women were carried out separately and results were adjusted for age and socioeconomic status. Results: The results show a significant trend in urinary disease mortality over exposure categories in women (P = 0.02) and a significantly increased risk in the highest exposure group (RR 1.48 (95% CI 1.09–1.96). For urinary disease morbidity the results show a significantly increased risk across all exposure groups for both sexes with relative risks in the highest exposure group of 1.33 (1.26–1.4) and 1.48 (1.41–1.56) for men and women respectively. The analysis for urinary disease sub-groups also show significantly elevated risks including a relative risk of 3.26 (3.07–3.46) for bladder dysfunction in women. Conclusions: An excess risk of urinary disease mortality and morbidity support the need for measures to reduce environmental cadmium exposure in the Avonmouth area.