Occurrence and human exposure to bromate via drinking water, fruits and vegetables in Chile

Bromate (BrO₃⁻) is an anionic contaminant known possess carcinogenic potential. Although some studies have reported the occurrence of bromate in drinking water, very little is known about its presence in fruits and vegetables, especially in Chile. In this study, we quantified bromate in soils (n = 29), drinking water (n = 43), surface water (n = 6), groundwater (n = 6), fertilizers (n = 7), fruits (n = 12) and vegetables (n = 42) collected across Chile. The highest average concentrations of bromate in soils (11.7 ng g⁻¹) and drinking water (8.8 ng mL⁻¹) were found in northern Chile. Additionally, drinking water collected from four regions of Chile showed higher concentrations of bromate (median:18.5 ng mL⁻¹) than the maximum contaminant level (MCL, 10 ng mL⁻¹). Concentrations of bromate in nitrogenous and non-nitrogenous fertilizers were similar (median: 2.51 μg g⁻¹). Leafy vegetables (median: 9.52 ng g⁻¹) produced in the northern Chile contained higher bromate concentrations than those produced in other regions (median: 0.24 ng g⁻¹). The estimated daily intakes of bromate via drinking water in northern, central and southern were ranged between 58.6 and 447 ng/kg bw/d. Leafy vegetables were an important source of bromate for all age group. The EDI values were below the respective reference dose (RfD) of 4000 ng/kg-day.