Polychlorinated biphenyl congeners in bento meals and estimation of dietary intake in Japan

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that are toxic and bioaccumulative. Although ready-to-eat meals such as bento are widely consumed in Japan, limited data exist on the levels of PCB congeners in these meals. In this study, 50 bento samples were analysed for all 209 PCB congeners and the PCB intake per meal was estimated to range from 16 to 9,320 ng/meal. Consumption of some bento samples resulted in estimated intakes exceeding the World Health Organization's tolerable daily intake. Bento containing mackerel had the highest mean intake (1,013 ng/meal), while that containing fried white-fleshed fish had the lowest (44 ng/meal). Non-dioxin-like PCBs comprised 90-97% of total intake. Congener profiles were dominated by hexa-, penta- and tetra-chlorinated biphenyls. These findings highlight the need to monitor PCBs in ready-to-eat foods and suggest that dietary variety, rather than frequent consumption of particular bento types, may help to reduce PCB intake.