Organochlorine pesticides in water and sediment from River Benue, Central Nigeria: An ecological and health risks assessment

Organochlorine pesticides (OCPs) have generated global concern due to their persistence in the environment and their potential ecological and health risks. This study was aimed at generating baseline data on the risks of OCPs in water and sediment from River Benue, Nigeria. The OCPs were determined using gas chromatography-mass spectrometer (GC-MS). The ecological and human risks were assessed using Sediment Quality Guidelines (SQGs) and Excessive Lifetime Cancer Risk due to multiple routes (ELCR) respectively. The sum of total (∑8OCP) in water (ng L-1 ) during wet season was 1.6114, and 4.3766 during dry season. In sediment, the results (ng g-1 ) were 9451.26 and 7194.88 during wet and dry seasons respectively. The ∑ELCR associated with water indicated very low risk with values less than the 1.0 x 10-6 threshold or low risk with 3.73 x 10-6 ELCR value. Risks due to inhalation of OCPs in sediment were also very low. ∑ELCR through accidental oral ingestion, dermal absorption and inhalation of OCPs in sediment was higher in children (12.90) than adult (3.10), and both were greater than the 0.1 threshold. Remediation and monitoring of the pollutants’ levels in River Benue are therefore required to avoid serious risks to aquatic lives and humans.