Ecotoxicological risk assessment in soils contaminated by Pb and As 20 years after a mining spill Pastor Jáuregui, R. Paniagua López, Mario Aguilar Garrido, Antonio Martínez Garzón, Francisco Javier Romero Freire, Ana Sierra Aragón, Manuel Toxicity risk Metabolic quotient Basal respiration Exposure pathway Bioassay Potentially toxic element This study evaluates the potential toxicity of the soils of the Guadiamar Green Corridor (GGC) affected by the Aznalcollar ´ mine spill (Andalusia, Spain), one of the most important mining accidents in Europe in recent decades. Twenty years after the accident, although the area is considered to be recovered, residual contamination in soils persists, and the bioavailability of some contaminants, such as As, is showing trends of increasing. Therefore, the potential residual toxicity in 84 soil samples was evaluated by bioassays with lettuce (Latuca sativa L.), earthworms (Eisenia andrei) and determining the microbial activity by basal respiration and metabolic quotient. The selected soils sampled along the GGC were divided into 4 types according to their physicochemical properties. In the closest part of the mine two soil types appear (SS1 and SS2), originally decarbonated and loamy, with a reduction in lettuce root elongation of 57% and 34% compared to the control, as well as a the highest metabolic quotient (23.9 and 18.1 ng CcO2 μg Cmicrob− 1 h− 1 , respectively) with the highest risk of Pb and As toxicity. While, located in the middle and final part of the affected area of the spill (SS3 and SS4), soils presented alkaline pH, finer textures and the lowest metabolic quotient (<9.5 ng CcO2 μg Cmicrob− 1 h− 1 ). In addition, due to Pb and As exceeded the Guideline values established in the studied area, the human toxicity risk was determined according to US-EPA methodology. Although the total contents were higher than the Guidelines established, the obtained hazard quotients for both contaminants were less than one, so the risk for human health was discarded. However, monitoring over time of the toxicity risks of the GGC soils would be advisable, especially due to the existence of areas where residual contamination persist, and soil hazard quotient obtained for As in children was higher and close to unity. 2023-02-06T13:03:46Z 2023-02-06T13:03:46Z 2022-10-29 info:eu-repo/semantics/article Pastor-Jáuregui, R... [et al.] 2022. Ecotoxicological risk assessment in soils contaminated by Pb and As 20 years after a mining spill. Journal of Contaminant Hydrology 251, 104100. [https://doi.org/10.1016/j.jconhyd.2022.104100] https://hdl.handle.net/10481/79706 10.1016/j.jconhyd.2022.104100 eng http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess Atribución 4.0 Internacional Elsevier