Comparing Levels of Some Heavy Metals in Rivers and Sedimentsfrom Two South-Western States of Nigeria

Abstract

Ten water and ten sediment samples from both Igbokoda and Apapa in South west, Nigeria were collected between March and August, 2018 for heavy metal analysis. The study aimed at using Potential Ecological Risk (PER) index to characterize rivers sediments and waters for possible environmental impact. The sampling span industrial, domestic and recreational areas. The water and sediment grab samples were treated using standard procedures. The filtrate from sediment was made up to 50 cm3 mark with distilled water and used for seven heavy metals determination using atomic absorption spectrophotometry (AAS). Contamination factor (CF) and Pollution load index (PLI) calculated for each metal in the sediments indicate moderate contaminations. However,
Cd in exception showed the highest potential ecological risk factor of 42.3 in Igbokoda. PER value of the Igbokoda sediment is 45.37 while that of Apapa sediment is 6.79. The potential risk pose by Cd alone in the sediment suggests that the Igbokoda water is unsafe for recreational and other beach activities. The recommendation from the study will suggest a proper treatment of wastewater and sewages before fluxing into both the Igbokoda and Apapa water bodies.