Toxicity and histopathological effects of oil-based drilling mud on edible swimming crab ( Callinectes amnicola )

Acute static bioassay was carried out to determine the toxicity and histopathology effects of oil-based drilling mud, using the edible swimming crab, Callinectes amnicola . The drilling mud evaluated is widely and consistently applied in exploratory operations and discarded haphazardly in the myriad of water systems, which characterise the Niger Delta basin. Pronounced mortal damage occurred in crabs exposed to as low as 2% concentration by volume of the drilling mud. Histo-pathological consequences of the tested mud on the crabs included irregular tissue shape, macrophages, inflammatory cells and basiophilic spots, etc. Uptake of barium, a carcinogenic component of the drilling mud by the crabs and implications for human consumers are also discussed. Animal Production Research Avancees Vol. 3 (1) 2007: pp. 64-68