Levels of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and dioxin-like PCBs in free range eggs from Vietnam, including potential health risks.

Chicken and duck eggs collected from three different areas in Vietnam were examined for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). These regions included a background area, an area sprayed with Agent Orange and the Bien Hoa airbase area where Agent Orange was handled by the US Army. The latter area now is inhabited and people keep their own laying hens. Egg samples were first screened with an in vitro reporter gene bioassay and a selection was analyzed by GC/HRMS. Samples from Bien Hoa airbase showed very high PCDD/F levels, up to 249 pg dioxin-equivalents (TEQ)/g fat, mainly due to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In the sprayed areas, levels (3.2-8.2 pg TEQ g(-1)) were comparable to those observed in background areas (3.2-8.2 pg TEQ g(-1) fat). The estimated average consumption of 22 g d(-1) of the highly contaminated eggs will result in a 2-fold exceedance of the current exposure limits for adults and 5-fold for children, even without considering other contaminated food sources. This indicates a potential health risk from consumption of these highly contaminated eggs, which were not yet considered as a source for exposure to PCDD/Fs of people living in the highly contaminated areas.