Bioaccumulation of Polychlorinated dibenzo-p-dioxins and Polychlorinated dibenzofurans (PCDD/Fs) in the maternal milk of mothers living in vicinity of Bien Hoa airbase

Abstract

Bien Hoa airbase is located in Bien Hoa city, Dong Nai province, Southern Vietnam. Several sites within the airbase are highly contaminated by Agent Orange/ Dioxin (AO/Dioxins) and thus this airbase is also commonly considered to be an AO/Dioxins hot spot. In this study, 40 maternal milk samples were collected from primiparas who have lived at least five years in four wards, namely Buu Long, Quang Vinh, Trung Dung, and Tan Phong, which are close to Bien Hoa airbase in order to investigate the level and distribution of Agent Orange/Dioxins exposure in different local communities. Seventeen toxic congeners of polychlorinated dibenzop-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in breast milks using the high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) method. Concentrations of Dioxin/Furan compounds in the four investigated wards ranged from 0.2 pgTEQ/g lipid to 26.1 pgTEQ/g lipid (mean concentration of 9.2 pgTEQ/g lipid). The highest mean concentration of Dioxin/Furan compounds was observed in Buu Long ward (11.8 pgTEQ/g lipid), followed by Tan Phong ward (11.0 pgTEQ/g lipid), and the lowest observed in Trung Dung ward (5.9 pgTEQ/g lipid). The mean concentration of 2,3,7,8-TCDD in Buu Long (6.1 pg/g lipid) was approximately 2-6 times higher than those in Tan Phong (3.2 pg/g lipid), Quang Vinh (1.8 pg/g lipid), or Trung Dung (1.1 pg/g lipid). These results imply the site-specific exposure to Dioxin/Furan compounds in different local communities living around Bien Hoa airbase.