Bioaccumulation of Heavy Metals and Hydrocarbons in Hemichromis Fasciatus Exposed to Surface Water in Borrow Pits Located Within Onshore Oil Exploration and Production Area

Abstract

A field bioaccumulation study was carried out. Juvenile hemichromis fasciatus in net cages were exposed to contaminated surface water in borrow pits located within oil exploration and prodn. (E & P) installations within the Niger Delta region of Nigeria during wet and dry seasons. Percentage mortality ranged between 2% and 3.8%. Assuming a first order kinetics and steady state at day 14; toxicokinetic variables were obtained for xenobiotics assessed. The up-take rate const. k, ranged from 38.47 × 10-2 d-1 (pit B, wet season) to 40.82 × 10-2 d-1 (pit A, dry season) for TPH, while PAHs ranged between 22.40 × 10-2 d-1 (pit B, wet season) and 24.98 × 10-2 d-1 (pit A, dry season) for both pits and seasons. Amongst the water borne metals k for hemichromis fasciatus ranged from 4.66 × 10-2 d-1 to 47.66 × 10-2 d-1 and 2.70 × 10-2 d-1 to 33.90 × 10-2 d-1 in pits A and B resp. during both seasons. The order of uptake was Fe < Cr < Ba < Cd < Zn < Cu < Ni, while As (arsenic) recorded a zero uptake. Calcd. BCF in both pits and seasons ranged from 2.832 LKg-1 to 4.844 LKg-1 for TPH and 2.636 LKg-1 to 8.0 LKg-1 for PAH, while for metals - Ba, Cd, Cr, Cu, Fe, Ni, Pb and Zn, values ranged between 0.211 LKg-1 to 71.727 LKg-1. Hemichromis fasciatus exhibited greater uptake of analytes in the dry season and the amt. of heavy metals accumulated were all below the provisional max. tolerable daily intake (PMTDI). [on SciFinder(R)]