Environmental health risk assessment of dioxin in foods at the two most severe dioxin hot spots in Vietnam

Background: Bien Hoa and Da Nang airbases were bulk storages for Agent Orange during the Vietnam War and currently are the two most severe dioxin hot spots. Objectives: This study assesses the health risk of exposure to dioxin through foods for local residents living in seven wards surrounding these airbases. Methods: This study follows the Australian Environmental Health Risk Assessment Framework to assess the health risk of exposure to dioxin in foods. Forty-six pooled samples of commonly consumed local foods were collected and analyzed for dioxin/furans. A food frequency and Knowledge-Attitude-Practice survey was also undertaken at 1000 local households, various stakeholders were involved and related publications were reviewed. Results: Total dioxin/furan concentrations in samples of local high-risk foods (e.g. free range chicken meat and eggs, ducks, freshwater fish, snail and beef) ranged from 3.8 pg TEQ/g to 95-pgTEQ/g, while in low-risk foods (e.g. caged chicken meat and eggs, seafoods, pork, leafy vegetables, fruits, and rice) concentrations ranged from 0.03 pg TEQ/g to 6.1 pg TEQ/g. Estimated daily intake of dioxin if people who did not consume local high risk foods ranged from 3.2 pg TEQ/kg bw/day to 6.2 pg TEQ/kg bw/day (Bien Hoa) and from 1.2 pgTEQ/kg bw/day to 4.3 pg TEQ/kg bw/day (Da Nang). Consumption of local high risk foods resulted in extremely high dioxin daily intakes (60.4-102.8 pg TEQ/kg bw/day in Bien Hoa; 27.0-148.0 pg TEQ/kg bw/day in Da Nang). Conclusions: Consumption of local high-risk foods increases dioxin daily intakes far above the WHO recommended TDI (1-4 pg TEO/kg bw/day). Practicing appropriate preventive measures is necessary to significantly reduce exposure and health risk. (C) 2015 Elsevier GmbH. All rights reserved.