Pollution Status of Inland Waterways Serving as Receptacles to Plastic Waste in Rivers State, Nigeria

Abstract

This study aimed at ascertaining the physicochemical characteristics of selected water bodies receiving solid plastic waste in Rivers State, Nigeria. Surface water and sediment samples were analysed for physicochemical parameters. Water, sediment and fish samples were monitored for presence of polychlorinated bisphenols (PCBs) and polycyclic aromatic hydrocarbons (PAHs). All physicochemical parameters monitored in Bonny River water and sediment samples were within WHO acceptable. However, the concentrations of nitrate and phosphate (62.675 and 1.28 ppm) in New Calabar River water samples were above WHO limits of 10 and 1 ppm respectively. The Cd values (0.045-8.27 mg/l) at both locations exceeded WHO 0.003 mg/l limit. Likewise, Mn concentrations (6.02-15.5 mg/l) exceeded WHO 5.5 mg/l. Mercury (0.075-1.39 mg/l) was the lowest occurring heavy metal in the water samples but the concentration was still high enough for concern, as the possibility for bioaccumulation in fish species in the river was high. Chloride levels (318.375-423.045 mg/l) in the water samples exceeded WHO limit of 250 mg/l for drinking water. The samples also had high iron content (0.635-16.19 mg/l). PAHs concentrations (252.0155-3533.14 ppm) in the water samples far exceeded the safe level of 10 mg/l for drinking water standard. PCBs levels in all fish samples (21.56-83.08 ppm) exceeded WHO maximum limit of 0.2 mg/kg Surface water, sediment and fish sampled contained objectionable concentrations of heavy metals, PCBs and PAHs. Users of these rivers for domestic purposes are at high risk of chemical poisoning from heavy metals, PCBs and PAHs.