Escalating health risk of thallium and arsenic from farmland contamination fueled by cement-making activities: A hidden but significant source

Soil-to-vegetable migration of toxic metal(loid)s is a pivotal pathway of human exposure to chemical intoxication. Thallium (Tl) and arsenic (As) are highly toxic metal(loid)s but their co-occurrence in soils and vegetables remain poorly understood. Herein, the present study focuses on potential health risk arising from co-occurrence of TlAs in various common vegetables cultivated in different farmlands around an industrial area featured by cement production activities. The results reveal obvious co-contamination of Tl (2.28 ± 1.39 mg/kg) and As (102.0 ± 66.7 mg/kg) in soils. Fine particles bearing sulfide and other minerals associated with Tl and As are detected in fly ash from cement plant, which can be migrated by wind over a long distance with hidden but inevitable pollution. Bioaccumulation Factor (BCF) and Enrichment Factor (EF) show that taro and corn preferentially accumulate Tl especially in underground parts. Hazard Quotient (HQ) indicates that consumption of these vegetables may result in chronic poisoning and/or even carcinogenic risk. The study highlights that the pathway and high risk of co-contamination of TlAs in the nearby farmlands posed by cement-making activities should be highly concerned.