Impact of Hydrocarbon and Heavy Metal Concentrations on Remediated Sites in Bodo, Rivers State, Nigeria

Crude oil spills as a result of pipeline explosions, artisanal refinery, and tanker disasters, which negatively impact soil, water, and biota in the Niger Delta region. Some polluted sites in the Niger Delta have been cleaned through concerted remediation efforts. However, many sites cleaned had been re-oiled from pipeline leaks from sabotage and artisanal refineries operated across the region. To ascertain the extent of pollution in some remediated sites in Bodo a study was carried out to investigate the concentration of total petroleum hydrocarbon (TPH) and heavy metal concentration in water sediment and biota (crabs and mudskipper). The samples were collected in situ, preserved in a cooler, and sent to the laboratory for the analyses of TPH, cadmium, lead, chromium, and lead. The result reveals a significant difference in TPH and heavy metal concentration between surface water and sediment (P<0.001). In contrast, there is no significant difference in chemical concentration between the dry and wet seasons or across months. Regarding biota, the ANOVA result reveals a significant difference between biota (F3, 36 = 8.21, P< 0.001). A higher concentration of Cadmium and Chromium was found in swimming crabs (Callinectes. amnicola), and a high cadmium concentration was found in fiddler crabs (Uca tangeri). At the same time, mudskipper (Periphthalmus. babarus) had the highest manganese concentration. The Tukey HSD test shows that the fiddler crab has the most significant chemical concentration from the permissible limit. The result implies that cleaned-up sites still have high concentration of harmful chemicals which poses a risk to human health.

Keywords: Biota, Heavy Metals, Mangrove Ecosystem, Pollution, Remediation.