CADMIUM BODY BURDEN IN RELATION TO CONCENTRATIONS IN SOIL AND VEGETABLES IN AN ENVIRONMENTALLY EXPOSED POPULATION

Abstract

ISEE-122 Introduction: It is well known that cadmium exposure may cause kidney damage, initially detected as a tubular dysfunction, assessed by measuring certain proteins and enzymes in urine. Recent studies have indicated that the kidney damage may occur also at low levels of environmental cadmium exposure. Cadmium body burden can be estimated by cadmium in urine (U-Cd), and a Swedish study (the OSCAR study) has shown a dose-response relationship with a ten percent prevalence of tubular proteinuria at U-Cd = 1.0. Aim: However, the exposure pathways are less clear and the present study aimed to assess the relative impact of different pathways of exposure to cadmium on the absorbed dose and body burden in a subgroup of the OSCAR population, who lived near a battery plant. The study also aimed to evaluate the contribution of locally produced food (vegetables) to total dietary cadmium intake. Methods: Cadmium levels in urine were determined in 492 individuals living near a closed down battery factory in Sweden. For each individual we created an environmental exposure-index based on emission data from the factory and number of years living at various distances from the plant. These data, as well as information on dietary habits and confounders, were collected via questionnaires. Samples of soil, carrots and/or potatoes were collected from 38 gardens and analyzed for cadmium. Results: Cadmium concentrations in carrots, potatoes and soil were high in the area near the factory. Daily consumption of potatoes and vegetables grown in the vicinity of the battery plant was estimated to increase cadmium intake by 40-60%. Increased U-Cd concentrations of cadmium (over 1.0 nmol/mmol creatinine) were significantly associated with intake of homegrown vegetables, environmental cadmium-exposure-index, female gender, age above 30 years and smoking an amount equivalent to one pack of cigarettes for more than 10 years. No increased U-Cd levels were shown in non-smokers, who did not eat homegrown vegetables, suggesting negligible exposure via ambient air. Conclusion: The present study shows that consumption of locally grown food constituted an important exposure pathway in subjects living near a nickel-cadmium battery plant, whereas exposure via ambient air was less important.