Monitoring of organic micropollutants in Ghana by combination of pellet watch with sediment analysis: E-waste as a source of PCBs

摘要

Plastic resin pellets collected at 11 beaches covering the whole Ghanaian coastline were analyzed for polychlorinated biphenyls (PCBs). PCB concentrations (Σ13 congeners) were higher in Accra, capital city, and Tema (39-69 ng/g-pellets) than those in rural coastal towns (1-15 ng/g-pellets) which are close to global background, indicating local inputs of PCBs. River sediments were also analyzed for PCBs together with molecular markers. Sedimentary PCBs concentrations were highest at a site (AR02) downstream of an electronic waste (e-waste) scrapyard. At the site (AR02), concentration of linear alkylbenzenes (LABs), a marker of municipal wastewater, was lower than another site (AR03) which is located at the downstream of downtown Accra. This result suggests that PCBs are introduced more to the river from the e-waste site than from activities in downtown Accra. PAHs concentrations were relatively higher in urban areas with strong petrogenic signature. Abundance of triphenylbenzenes suggested plastic combustion near e-waste scrapyard.