Carbonate-rich mining tailings in Lavrion: risk assessment and proposed rehabilitation schemes

摘要

In Lavrion, Greece, the mining and metallurgical activities that were particularly intensive during the last century resulted in the generation of huge amounts of wastes, including acid-generating sulfidic tailings, carbonaceous tailings and lags. Their improper management in the past resulted in the migration of heavy metals to the surroundings, contributing to widespread soil contamination. As a result, the local population is exposed to multiple hazardous pollution sources. the present study aims to combine the available geochemical characterisation techniques and risk assessment tools in order to identify the specific risks associated with the carbonate wastes and determine the remedial measures required accordingly. The risk assessment study of the carbonate tailings resulted in the identification of three high-risk exposure routes for humans: direct contact, ingestion and inhalation of contaminated material. Plant uptake and secondary contamination of soils are rated as high-risk exposure routes only for 'Savoura' tailings. Quantification of the human health risks indicated that direct ingestion of contaminated particles is the most important exposure route for the intake of contaminants by humans. The intake of Pb, As and Cd by adults and children living in the vicinity of carbonaceous tailings was found to exceed the maximum tolerable risk. Based on the risk assessment results, several remediation options were examined, aimed at either removing the source or breaking the significant source-pathway-target relationships.