Cumulative Internal Dose of Uranium in Workers Close to Phosphogypsum Waste Piles

Abstract

ISEE-0502 Background and Objectives: Huelva city inhabitants have shown concern in the last decades before the environmental impact and the possibility of health effects due to the proximity of a chemical and metal industry park and phosphogypsum waste piles. Despite the existence of an air pollution surveillance system in the area, and the availability of studies that have characterized the pollution within the phosphogypsum waste piles, there are no studies on the bioaccumulation of pollutants related to the phosphogypsum waste piles in subjects working in their proximity. Methods: Cross-sectional epidemiological study design. We recruited 125 volunteer chemical and metal industry workers from different geographical areas in Spain. We analyzed the internal cumulative dose of uranium 238 in 51 of them (46 men) in washed toenail samples via ICP-MS following microwave assisted acid digestion. 32 volunteers worked in the chemical and metal industry next to the phosphogypsum waste piles, and 19 volunteer workers worked in the chemical and metal industry of other study areas without a phosphogypsum pile nearby. Results: 14 (44%) out of 32 workers next to the phosphogypsum waste piles showed traces of uranium 238 in toenails, for none (0%) of the 19 volunteer workers from the other study areas without a phosphogypsum pile nearby (P = 0.0007; Chi square test). None of the 14 workers with traces of uranium worked for the companies that generate the phosphogypsum waste materials. Conclusion: Our results suggest that working nearby the phosphogypsum waste piles and/or into the industrial park of Huelva city might contribute to the bioaccumulation of uranium 238. As the sample size is small, and we did not take into account the possible contribution of dietary factors, results should be interpreted with caution.