Quantification of Pollutant Levels in Water, Sediment and Winkles in Akani Obio Uruan River, Nigeria

Abstract

The levels of some trace metals (Cd, Cr, Cu, Pb and Zn) were quantified in water, sediment and two species of winkles (Pachymelania bryonensis and Pachymelania fusca mutans) in Akani Obio Uruan River from August to September 2018 (wet season) and February to March 2019 (dry season), using Varian spectra 100 atomic absorption spectrophotometer. The levels of some physicochemical parameters (temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), electrical conductivity (EC), total dissolved solid (TDS), nitrate, sulphate and phosphate) were equally quantified in water. From the results, Cd level of 0.088 mg/l in water was higher than those of the other trace metals investigated. Accordingly, Cu level of 0.602 mg/kg in sediment was higher than 0.017 mg/kg in water and 0.077 mg/kg in one species of the winkles. Zn level of 0.141 mg/kg in one species of the winkles was higher than those of the other metals. In general, the levels of most of the metals were higher in all the samples during the wet season. This could be attributed to excessive water runoff during the wet season which could have resulted to the leaching of various kinds of wastes into the water bodies. Interestingly, the levels of all the trace metals investigated in all the samples were below the maximum acceptable limits stipulated by WHO and the US environmental protection agency (USEPA). Physicochemical examination revealed that the levels of pH, temperature, TDS, EC, nitrate and sulphate were below the maximum permissible limits set by WHO. The levels of DO and phosphate in the water were however higher. This may have deleterious effect on aquatic ecosystem and the health of the rural dwellers that consumed the winkles and use the river water directly for domestic purposes without treatment.

Human Health Risk Assessment of Some Trace Metals through Fish Consumption from Qua Iboe River, Oruk Anam, Nigeria

“…Fish samples: Fish samples were collected from the local fishermen fishing in the river using local fishing traps (Ikpa) set adjacent to the sampling locations at dusk and inspected at dawn [9]. Five medium sized fish samples were obtained very early in the morning and were put in a locally made aquarium and transported immediately to laboratory for further analysis [3]. Prior to analysis, the fish samples were washed with distilled water to remove loosely held particles before they were gutted and decapitated using stainless steel kitchen knife.…”

“…Temperatures reaching extremes of heat or cold in aquatic environment could lead to survival of only a few organisms. Depletion of dissolved oxygen (DO) can lead to extinction of aquatic organisms [12].…”

“…''Longer period of exposure of humans to contaminants such as trace metals, chemicals and chemical agents in the environment through oral intake can result in high risk to human health' [2]. ''Higher levels of chemical agents in water, food, air and soil are potentially harmful to humans as a result of exposure [3]. "There are so many sources of contaminants into water bodies.…”

“…The end products and the after effects of all these activities are usually washed into the aquatic environment when it rains, polluting the ecosystem with all kinds of trace metals. Many studies have been carried out on the concentration of trace metals in different portions of Qua Iboe River" [3]. However, information on the emerging trends of these chemicals in Qua Iboe River, Oruk Anam, especially the information on fish samples are non-existent, therefore, there is every need to quantify the levels of trace metals in fish from Qua Iboe River, Oruk Anam and also to assess the health risk on humans associated with the consumption of the fish.…”

Comparison of Investigated Levels of Physicochemical Parameters in Qua Iboe River, Oruk Anam, Nigeria with Portable Water Standards

“…''Water quality is continually threatened due to increasing inputs of the end products of anthropogenic activities and this attracts greater attention of government in the control of water pollution. This is because contaminants in air, soil or on land ultimately end up in the aquatic ecosystem through local precipitation, water run-off and leaching of rocks and solid wastes'' [8,9]. Investigation of the physicochemical parameters in water samples from Qua Iboe River, Ikot Ekpene stretch, Nigeria, revealed that the levels recorded were all within permissible limits set by World Health Organisation [1,6].…”