Concentrations, Sources, and Risk Assessment of Organohalogen Compounds in Soils from Kiambu to Mombasa, Kenya

Concentrations, sources, and risk assessment of 16 organochlorinated pesticides (OCPs), seven polychlorinated biphenyls (PCBs) and seven polybrominated diphenyl ethers (PBDEs) were determined in soils from Kiambu to Mombasa in Kenya. The total concentrations of OCPs ranged between 7.62 and 76.09 ng/g, dominated by HCHs. Source identification displayed recent inputs and historical use of DDTs and lindane. The total concentrations of PCBs ranged from 9.90 to 20.8 ng/g with an average of 14.40 ng/g dominated by penta-PCBs from old transformers leakages. The total PBDEs concentrations were in the range of 1.89–38.36 ng/g and with a mean of 11.38 ng/g. Electric and electronic equipment waste and PBDE containing materials as sources of PBDE. The risk assessment of OCPs and PCBs showed low potential human health risk from OCPs, while PCBs indicated to pose a high risk.