This paper presents the genotoxic effect of effluent from a pharmaceutical plant in Ota, Ogun
state, Nigeria using the rat bone-marrow metaphase chromosome assay. The effluent was
examined for some standard physical and chemical properties. Rats were intraperitoneally
exposed to 1%, 5%, 10%, 25% and 50% (v/v, effluent/distilled water) concentrations of the
effluent for 48 hr. Distilled water and cyclophosphamide (40 mg/kg body weight) were used as
the negative and positive controls respectively. The erythroblasts of bone marrow cells examined
post treatment show structural chromosomal abnormalities such as translocation, acentrics,
breaks, dicentrics and rings. The effluent also induced concentration-dependent significant
(p<0.05) reduction in mitotic index. Physico-chemical analysis of the tested sample showed the
presence of constituents capable of inducing mutation in biological system. The interaction of
these constituents with the genetic material in the bone marrow cells caused the observed
anomalies. These findings indicate that the tested pharmaceutical effluent is a potent clastogenic
and mutagenic agent and suggest potential adverse health risks to exposed living organisms.
