A study of neurotoxicity of BHC in relation to residual accumulation on the brain tissue of Heteropneustes fossilis (Bloch).

Neurotoxic effect of BHC, the organochlorine pesticide in Heteropneustes fossilis has been studied exposing at the dose concentrations of 1 ppm, 5 ppm and 10 ppm in lab aquarium for 96 hours over a period of one year. The results showed the behavioural abnormalities in different exposure concentrations such as dysfunction of endocrine gland, excretion of mucus, dispigmentation, sign of restlessness, erratic swimming with rapid jurkey movement, spiralling and convolution showing severe effect in central nervous system. Therefore an attempt has been made for monitoring of BHC residues viz. alpha, beta, gamma isomers in the brain tissue exposed to different sublethal concentrations using Gas liquid chromatography. The mean values of isomers were found to be 1.587 microg/gm for 1 ppm, 2.993 microg/gm for 5 ppm and 3.78 microg/gm for 10 ppm test group. Severe behavioural abnormalities were recorded at high dose concentration of pesticides with higher accumulation of pesticide residues in brain tissue.

Dermal toxicity of hexachlorocyclohexane (HCH) in rabbit.

Application of HCH (25 mg/kg) on dorsal, ventral and thigh regions of the skin of male rabbits resulted in poisoning and mortality of animals. Morphological changes in skin, liver, kidney, testes and cerebellum together with highly significant alterations in serum and liver enzymatic activity and residue in blood suggested that absorption of HCH and its toxicity could be severe when the pesticide comes in contact with the skin of thigh region of body.