RESUMO
This paper investigates the concentrations of PCBs in the water and sediment media and its bio-concentration in the fish host-parasite bentho-pelagic food chain in Epe lagoon. Samples of water, sediment, plankton, mollusks, fish and intestinal helminth parasites were collected from three stations (Oriba, Imode and Ikosi) in Epe Lagoon. Concentration of total PCBs in the surface water and sediment across the stations ranges from 3.20 to 6.00 ppb and 405.50-860.70 ppb respectively. Imode had the highest concentrations. The plankton bio-concentrates most PCBs in Ikosi (286.70 ppb) followed by Imode concentration (165.40 ppb), then Oribo (92.60 ppb) with total bio-concentration of 544.60 ppb. Surface water temperature negatively and strongly correlates with PCBs in the plankton. The planktons bio-concentrates total PCBs 44 times than that in the surface water. Chrysichthys nigrodigitatus bio-concentrates total PCBs 48 times than that in the surface water. Bioaccumulation of PCBs in human food chain could pose health risk.
Assuntos
Bioacumulação , Peixes-Gato/metabolismo , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Helmintos/metabolismo , Bifenilos Policlorados/análise , Poluentes Químicos da Água/análise , Animais , Peixes-Gato/parasitologia , Cadeia Alimentar , Água Doce/química , Água Doce/parasitologia , Sedimentos Geológicos/parasitologia , Humanos , Nigéria , Plâncton/metabolismo , Bifenilos Policlorados/metabolismo , Poluentes Químicos da Água/metabolismoRESUMO
This paper assesses the role of intestinal helminth parasite of Macrobrachium vollenhovenii on host metal accumulation in Lekki lagoon, Lagos, Nigeria. Lead, zinc, copper, chromium and iron concentrations were determined in water, sediment, intestinal parasite, intestine of infected and non-infected prawns. Intestinal nematode parasite Cucullanus sp. was identified. Pb and Cr were not detected in the water and sediment. The sediment had higher concentrations of the metals than the water medium, and exceeded the WHO limits for Zn, Cu and Fe. Cucullanus sp. accumulated Zn 19 times, Cr several thousand times more and Fe 11 times more than the host intestine (wet wt). This parasite could have accumulated these metals from its host, reducing the concentration of these metals in the tissues of the infected prawns compared to non-infected ones. The infected and non-infected prawns accumulated Zn and Fe several times more than the water medium. The parasite influenced metal accumulation in the host tissue and pose ecological risk.
