Some chlorinated pesticides and polychlorinated biphenyls (PCBs) continue to be reported as environmental problems in some areas of Vietnam. The aims of the study were to determine levels of these contaminants in delivering women's plasma samples, and to identify exposure risk factors.
The research took place in 2005 in 2 communities in south-central Vietnam (Khanh Hoa Province), namely the coastal city of Nha Trang and the rural district of Dien Khanh located about 10 km inland. The design of the study was cross-sectional. In all, 189 delivering women's blood samples were collected and they were interviewed at home about related information within 4 months after delivery. The OC concentrations were quantified on GC/MS with a method as described by Sandanger et al. The GC/MS Shimadzu QP-5050A and Fishon MD-800 were used in Viet Nam and in Norway, respectively.
The main findings in plasma (n = 189) were relatively high mean concentrations of p,p′-DDE (12.2 μg/L in Nha Trang and 11.4 μg/L in Dien Khanh) and p,p′-DDT (1.2 μg/L in Nha Trang and 1.1 μg/L in Dien Khanh) with no significant community differences. The ratio of p,p′-DDE/p,p′-DDT were 11.5 in Nha Trang and 12.7 in Dien Khanh. Mean concentrations of PCB 153 (0.15 μg/L in Nha Trang and 0.10 μg/L in Dien Khanh) and other congeners were low in both communities. Age and parity (all compounds), as well as community of residence for PCB 153, were the most important predictors of plasma organochlorine concentrations.
The results suggest, as in other Vietnamese OCs studies, recent use of p,p′-DDT in this area of Vietnam despite its ban. The relatively high levels of p,p′-DDE and p,p′-DDT and PCB 153 in delivering women blood give reason for concern about the long-term effect on children's health. Because the breast-feeding should remain a priority, the education on the hazards of OCs use and the dietary advice for women is important to circumvent high body burdens.