Exposure and health effects follow-up study of residents near a former smelter site.

The Seo-Cheon Janghang Smelter in South Korea closed in 1989 owing to its contribution to environmental pollution. The emissions from the smelter likely affect various environmental media and also pose significant health risks to nearby residents, particularly in relation to exposure to heavy metals such as lead, cadmium, and arsenic. Although the environmental impacts of the smelter are known, long-term follow-up studies on heavy metal exposure in nearby residents remain limited, especially after remediation. This study aimed to assess the levels of heavy metal exposure and associated health effects, particularly on renal and bone health. We analyzed blood and urine samples from 37 volunteers, collecting demographic, lifestyle, and exposure-related data through interviews. Renal function tests and bone mineral density measurements were conducted. The geometric means for blood lead (bPb) and blood cadmium (bCd) were 1.95 μg/dL and 2.68 μg/L, respectively. The mean urinary cadmium (uCd) concentration was 3.74 μg/g cr. Urinary total and harmful arsenic concentrations were 165.7 μg/L and 1.00 μg/L, respectively. The bPb levels significantly decreased from 2008 to 2020, whereas cadmium levels did not show significant change overall. Among 28 participants tested in both years, bCd levels decreased for individuals living > 2 km from the smelter, while remaining stable for those closer. The uCd levels significantly decreased only in individuals who had relocated > 2 km away from the smelter. Despite remediation efforts, uCd levels remain persistently elevated. These findings underscore the need for continuous exposure monitoring and longitudinal health assessments of residents living near the former smelter.