Assessment of Lagos soils for some persistent organic Pollutants

Abstract

Contamination of Lagos soils with persistent, bioaccumulative and toxic micropollutants (PBTs) may not only affect the non-target species residing in the soil, but also raises the concern of the possibility of the chemicals finding their way into the Lagoon and other water courses via soil run-off and leaching. In this study, soil samples were collected from three busy areas of Lagos (Apapa, Okobaba and Iddo) and analyzed for Polychlorinated Biphenyls (PCBs), Organochlorine pesticides (OCS), and Polycyclic Aromatic Hydrocarbons (PAHs). Gas Chromatography with Mass Selective Detector (GC/MSD) was used for the analyses. Iddo had the highest percentage organic carbon content of 39.39% with highest total PAHs of 2,706.93 ng/g. The highest total PCBs of 23.63 ng/g was found at Apapa 3 which was one of the three sampling points in Apapa. PCB 74 was the only
PCB found in all the soil samples and ranged between 3.55 ng/g and 23.64 ng/g at Apapa 1 and Apapa 2 respectively. High concentrations of the following organic compounds were also obtained at the following locations- naphthalene (1,625.10 ng/g) at Iddo; dichlorodiphenyldichloroethylene (p,p'DDE ), (117.98 ng/g) at Okobaba, and PCB 74 (23.63 ng/g) at Apapa 1. The results obtained showed that the higher the municipal activity, the higher the percentage organic carbon content.

Key words: Bioaccumulative and toxic micropollutants, Gas chromatography/Mass selective detector, Persistent organic carbon, Soil organic pollutants