Monitoring polychlorinated dibenzo-p-dioxins/dibenzofurans and dioxin-like polychlorinated biphenyls in Africa since the implementation of the Stockholm Conventionan overview

Polychlorinated dibenzo-p-dioxin (PCDDs), polychlorinated dibenzofurans (PCDF), and dioxin-like polychlorinated biphenyl (dl-PCB) are groups of toxic compounds released into the environment as unintentional by-products of combustion. They persist, bioaccumulate through the food chain, and cause adverse health effects. This review attempts to collate available information on the release of PCDD/Fs and dl-PCBs and other critical data relevant to their monitoring in Africa during the existence of the Stockholm Convention (SC). Much as the implementation of the SC may be lagging, literature showed that there has been encouraging efforts that have been made with respect to PCDDs/Fs and dl-PCBs monitoring in Africa. Results from a global monitoring study showed that PCDD/Fs released to air in Africa stood at 18-532fg WHO98 TEQ/M-3 while dl-PCBs were 7-278fg WHO98 TEQ/m(3). In human milk, the total concentration of PCDD/Fs, i.e., WHO 2005 TEQ LB has been reported to range from 0.5ng/g fat to 12ng/g fat. Fourteen laboratories in Africa participated in inter-laboratory assessments of persistent organic pollutants (POPs) with two specifically for PCDD/Fs analysis. This shows that some efforts are being made to boost capacity in Africa. Levels of PCDDs/Fs and dl-PCBs in clay consumed by pregnant women have been reported in Cameroon, Democratic Republic of Congo (DRC), Nigeria, Zimbabwe, Cote d'Ivoire, and Uganda with a maximum concentration of 103pg TEQ/g. This finding was very significant since women are the most impacted through exposure to POPs, a fact that is acknowledged by the SC.