Occurrence and Distribution of Polybrominated Diphenyl Ethers in Water from Nairobi River Basin, Kenya, East Africa

Abstract

Polybrominated diphenyl ethers are linked to adverse health effects that include thyroid hormone disruption, neuro-developmental deficit, abnormal pregnancy, and potential carcinogens. This study was aimed at assessing the concentrations of selected Polybrominated diphenyl ether compounds in water of Nairobi River. Water samples were collected by grab method from nine sites along the river and analysed for brominated diphenyl ethers using gas chromatography coupled with mass spectrometer. The mean concentration of polybrominated diphenyl ethers residue in water ranged from <0.0009 to 72.89 ± 6.15 ng/L. The dominant congeners were 2,2′,4,4′-tetra- bromodiphenyl ether, 2,2′,4,4′,5,5′-hexa-bromodiphenyl ether, 2,2′,4,4′,6-penta-bromodiphenyl ether, 2,2′,4,4′,5,5′-hexa-bromodiphenyl ether and 2,2′,4,4′,5,6′-hexa-bromodiphenyl. The highest mean concentration of 2,2′,4,4′-tetra- bromodiphenyl ether was 72.89 ± 6.15 ng/L, 2,2′,3,4,4′-penta- bromodiphenyl ether was 14.08±0.68 ng/L, 2,2′,4,4′,6-penta-bromodiphenyl ether was 43.67±1.47 ng/L, 2,2′,4,4′,5,5′-hexa-bromodiphenyl ether was 24.78±2.49 ng/L, and 2,2′,3,4,4′,5′,6-hepta-bromodiphenyl ether was 11.75±0.97 ng/L. Consequently, as these compounds are known to bio-accumulate in fatty tissues, continued use of the river water poses a health risk to animals and humans due to contamination across the food chain.