Surveillance of dioxins and polychlorinated biphenyls (pcbs) in food commercialized in Barcelona, Spain

This study explored the potential use of seven congeners of polychlorinated biphenyls (PCBs-7) as indicator compounds for the presence of dioxins and PCBs in food samples, as part of the routine surveillance programme of a public health agency. Samples of 24 foodstuffs with high fat content were collected (ten fresh fish, six dairy products, five meat and three eggs). Duplicate analyses were performed. A research laboratory tested samples for seven polychlorinated dibenzo-p-dioxin (PCDDs), ten dibenzofurans (PCDFs) and twelve dioxin-like PCBs, with limits of detection in the range of ng kg^-1 (ppt). The public health services official control laboratory tested samples for PCBs-7, with a limit of quantification of 5 mgkg_1 (ppb). The research laboratory detected the presence of dioxins and dioxin-like PCBs in all samples; fish samples had the highest levels (0.04-10.3 pg WHO-TEQ g^-1). The public health service official control laboratory detected PCBs-7 only in five samples, which were all fish. Comparing the results in the two laboratories there seems to be an association between the detection of PCB-7 and the presence of higher levels of PCDD/Fs and dioxin-like PCBs. The use of PCB-7 as an indicator compound may be a practical surveillance strategy for those foodstuffs with higher concentrations of dioxin-like congeners.