Is the Slag Heap of a Former Ferrochromium Plant a Significant Environmental Hazard?

This study assessed the possible impact of a former ferrochromium plant in Siechnice (Lower Silesia, Poland) on water reservoirs and living organisms. The metal concentrations (Zn, Cu, Pb, Fe, and Cr) in the sediments were determined, along with ecotoxicological studies that were conducted on both the sediments and the surface water of three water bodies that border the slag heap. The samples of the sediments and water were taken at different distances from the landfill area. The studies also covered a human health risk assessment. The highest concentrations of all the studied elements were observed in the sediments taken from the water reservoir closest to the landfill. In the case of the sediments, a 30% death rate for Heterocypris incongruens (Ostracodtoxkit F) was recorded at the same site. Additionally, at this site, the ecotoxicological studies on the surface water revealed the highest mortality for Daphnia magna (Daphtoxkit F magna) and the lowest values of LC50 for algae (Algaltoxkit). The health risk assessment of the sediments was estimated by calculating the noncarcinogenic health risk using the hazard quotient (HQ) and hazard index (HI), and the carcinogenic risk was calculated using the excessive risk of cancer development (ECR) measurement. The hazard index (HIing) for Cr exceeded 1 for children, which suggests that possible adverse health effects might occur for humans. The ECR values calculated for Cr and Pb were above the range limit of 10−6. The value for Cr was the highest for the sediments from the closest water reservoir to the landfill for both children and adults. Studies prove that the water reservoirs located near landfills pose potential ecological risks, and the risk is the highest where the distance is the shortest from the slag heap. In prospective human health risk assessments, the sediments from the closest water body pose a potential carcinogenic health risk to humans, especially to fish consumers, i.e., the residents of neighboring areas who might experience severe health problems from the intake of Cr and Pb through fish consumption. Significant steps should be taken to reduce Cr concentrations in the sediments to minimize the risk of human health adverse effects.