Trace metals in intertidal sediment of mangrove-sheltered creeks in Niger Delta, Nigeria: Variability before and after crude oil spillage

Abstract

Trace metals (Zn, Cu and Pb) fluxes were studied in five intertidal flats at Bodo Creek, Eastern Niger Delta, Nigeria in 2006, and re-evaluated in 2010 following two major oil spills that occurred in the creek. This study is the first to look at trace metal loads in the interstitial sediments of Bodo creek. Standard methods were employed in the sampling campaign and analysis. The concentration of all metals under study were higher than stipulated limit by WHO (2006) during post spill analysis. Concentration of Zn did not vary between stations and months pre-spill but did in post-spill, having values slightly higher than WHO (2006) stipulated limit. During the pre-spill sediment analysis, Pb concentrations ranged from no detection to 0.0012 mg/kg in 2006, increasing to 0.169 mg/kg post spill in 2010. Cu content ranged from 0.1312-0.1858 and 0.3374-0.4504 mg/kg pre-and post-spill, respectively. In addition to oilinduced metal loadings, the metals concentration dynamics show strong correlation with season. Metals had higher concentrations during the dry season due to reduced water volume in the creek and consequently less dilution. Implication for uptake, bioaccumulation and biotransformation by food species in the creek catchment above biosafety limits for user population is stressed and measures to avert public health consequences are advocated.

Risk Assessment of Heavy Metals in Food Crops at Abandoned Lead-Zinc Mining Site at Tse-Faga, Logo, Lga, Benue State, Nigeria

“…The highest bioaccumulation factor (BAF) of zinc was recorded in Carica papaya flesh 0.754, Manihot esculenta tuber peels and flesh 0.181 was the lowest. All the results of transfer factor of Zinc from soils to food crops were below the stipulated standard of BAF > 1, according to [33]. However, Zea Mays with BAF 1.011 was recorded the highest BAF, we can therefore conclude that, among all food crops under study, Zea Mays had the highest bioaccumulation factor.…”

“…Generally, zinc (Zn) concentration in all the food crops from the mining site revealed the highest concentration in Carica papaya with mean concentration and standard deviation of 0.50 ± 0.01 Mg/kg while the lowest mean concentration values were recorded in Manihot esculenta peel 0.122 ± 0.01 mg/kg (Table 2). [32] reported values of 1.205 -1.017 mg/kg, [33] reported lead increase over a post spill event from NDL to 0.16 mg/kg over seasons. These results are relatively higher than the results of this work.…”

Conflicts – Oil Exploration and Water

“…[64,72] Pre-spill and post-spill metal concentrations in surface water and sediments in Bodo Creek were compared. [73] They reported significant increase in metal (zinc, lead and copper) loads postspill. A follow-up study [74] on metal concentrations in water and sediment in Bodo Creek also reported concentrations of magnesium, iron, copper, zinc, chromium, lead and cobolt as being higher than the World Health Organization [58] recommended permissible levels for surface and drinking water.…”

“…Pre‐spill and post‐spill metal concentrations in surface water and sediments in Bodo Creek were compared . They reported significant increase in metal (zinc, lead and copper) loads post‐spill.…”

Suspended Marine Litter in Akwa Ibom State, Nigeria: A Case Study of Cross River, QUA Iboe River and Jaja Creek

“…Water bodies are home to over 97 percent of life on our planet and constitute an essential part of our biosphere [1]. Sadly, human activities in the last 5 decades have resulted in the pollution of the ocean and the marine environment, led to over exploitation of living resources, alteration and destruction of marine habitats and influx of solid wastes such as plastics [2].…”