Heavy metal accumulation in organs of Oreochromis niloticus (Linnaeus, 1758) from industrial effluent-polluted aquatic ecosystem in Lagos, Nigeria

Abstract

The concentrations of four heavy metals (Zn, Fe, Cu, and Pb) in water, sediment, and tissues (gill, muscle, brain, and intestine) of Oreochromis niloticus from a segment of the Lagos Lagoon complex were monitored for 10 months (July 2012-April 2013) spanning wet and dry seasons. Three sampling stations were selected: Ologe Lagoon, the nearest to the point where effluent is discharged from Agbara Industrial Estate, the Owo River is upstream before the point of discharge of industrial effluent, and Etegbin is downstream. In most cases, the highest concentrations of heavy metal in fish tissues were recorded in samples obtained from Ologe Lagoon. The ranges of concentrations of heavy metals in the tissues of the fish were 4.06 ± 2.45-49.94 ± 13.11, 81.27 ± 28.52-2044.64 ± 554.77, 10.90 ± 7.69-41.10 ± 11.24, and 0.12 ± 0.07-1.81 ± 3.12 mg/kg for Zn, Fe, Cu, and Pb, respectively. There were significant negative correlations (lowest; r = -0.24, p < 0.01, n = 30; highest; r = -0.58, p < 0.01, n = 30) between fish tissue metal concentrations and size of fish from Ologe Lagoon. Also, significant positive correlations (lowest; r = 0.48, p < 0.05, n = 30; highest; r = 0.93, p < 0.01, n = 30) between concentrations of Cu in sediment and tissues of O. niloticus were observed. The concentrations of the metals in the tissues of O. niloticus have exceeded the limits recommended by WHO. The maximum safe daily consumption (MSDC) value of Fe in Ologe Lagoon was lower than the recommended average daily intake of fish for humans. This indicated that O. niloticus from Ologe Lagoon may not be safe for human consumption. Therefore, there is a need for regular monitoring of heavy metal in these water bodies and enforcement of existing laws on the treatment of effluent before they are discharged into aquatic ecosystems.

Impacts and Policy Implications of Metals Effluent Discharge into Rivers within Industrial Zones: A Sub-Saharan Perspective from Ethiopia

“…Industrial effluents containing metals, and their accumulation in sediments and biota, present a persistent threat to ecosystems health (Gaur et al 2005 ; Jining and Yi 2009 ; Kelderman 2012 ; Xu et al 2014 ). This holds also for sub-Saharan African countries, where regular monitoring is limited (Akele et al 2016 ; Ndimele et al 2017 ). Thus, identifying effluent concentrations and discharge management are of increasing importance if environmental risks and hazards are to be addressed (Rudi et al 2012 ).…”

Industrial Pollution Evaluation through Enzymatic Biomarkers at Different Localities of El-Sadat Industrial City, Menofia, Egypt.

“…Heavy metals are classified as the most dangerous pollutant of anthropogenic environmental pollutants not only for their toxicity to the biota but also for not chemically or biologically degradable, persistence in the environment and accumulative element in any ecosystem even in human body (Lee et al, 2006;European Environment Agency, 2011;AESAN, 2012;Guo et al, 2012;Koz et al, 2012). Not all heavy metals are dangerous elements but there are biologically essential metals which play important role in a biological system in human being on opposite to non-essential elements which are toxic to living organisms even at quite low concentrations (Alkan et al, 2015;Ndimele et al, 2017).…”

Accumulation of Heavy Metals by Wild Mushrooms in Ibadan, Nigeria

“…The distribution of heavy metals in different compartments of the ecosystem is regulated by physical and chemical processes (dilution, diffusion, precipitation and sorption), as well as other processes such as uptake and elimination. 2 At low levels, metals such as copper (Cu), cobalt, zinc, iron and manganese are essential for enzymatic activity and many biological processes; however, these metals are toxic at high concentrations. 3 Other metals such as cadmium (Cd), mercury (Hg) and lead (Pb) have no known essential role in living organisms and are toxic, even at low concentrations.…”

“…These pollutants have detrimental effects not just on organisms in the environment, but also on humans through the food chain. 2 Therefore, the aim of the present study was to investigate the metal content of local wild mushrooms with a view to educating locals on the safety of their consumption.…”