Eight duck farms and a local market in Suphanburi province, Thailand adjacent to paddy fields were selected for this study. The concentrations of endosulfan isomers (α- and β-endosulfan) and endosulfan sulfate in environmental matrices (water, soil, feed) and duck eggs were determined. Human health risk via the contaminated egg consumption was also evaluated. Analysis of environmental matrices found both endosulfan isomers (α- and β-endosulfan) and endosulfan sulfate in most samples. Endosulfan sulfate was predominantly found in all matrices followed by β- and α-endosulfan, respectively. The total endosulfan concentrations were in the following order: feed > soil > water. However, the levels of endosulfan detected were lower than the regulatory maximum residue limit of endosulfan, except in water (>0.200 ng mL(-1)). Endosulfan sulfate in duck egg samples was also predominantly detected in both yolk and albumin. The average total endosulfan residues (∑endosulfan) in yolk (6.73 ng g(-1)) were higher than in albumin (4.78 ng g(-1)). According to principle component analysis, we found that paddy soil surrounding the duck farms is the suspected source of endosulfan contamination in husbandry water which subsequently contaminates duck eggs. The estimated daily intakes (EDIs) of these endosulfan-contaminated eggs were well below the acceptable daily intake (ADI) for endosulfan (6 μg kg(-1) day(-1)). However, the consumption of this contaminated duck eggs should be of concerns in regard to chronic exposure. Therefore, the better environmental managements to reduce endosulfan residues can play a crucial role for decreasing human health risk.
Keywords: ADI; Consumption; Duck eggs; Endosulfan; Health risk assessment.