Affiliations: National Environmental Engineering Research Institute
(NEERI), Nagpur 440020, India | Department of Civil & Environmental Engineering,
University of Windsor, Windsor N9B 3P4, Ontario, Canada | Government Medical College, Nagpur 440025, India
Abstract: The effects of pesticides on blood characteristics and histological
changes in erythrocytes of the fish species Cyprinus carpio and Puntius ticto
were studied. The fishes were exposed to sub lethal concentrations of different
chlorinated pesticides namely aldrin, dieldrin, DDT, BHC and chlordane for 10,
20 and 30 d in continuous flow-through test. The LC_{50}
values were calculated based on acute toxicity tests and the sublethal doses
were arrived at for chronic bioassay studies. Results showed an increase in
haemoglobin content of both Cyprinus carpio and Puntius ticto in case of aldrin
and dieldrin. Haemoglobin content reduced from an initial 13 g/100 ml to 8.07
and 10.15 g/100 ml in case of Cyprinus at the end of ten days exposure to
aldrin and dieldrin respectively, and gradually increased to 8.7 g/100 ml and
10.15 g/100 ml after 20 d of exposure. The haemoglobin content after 30 d
exposure to aldrin and dieldrin was 10.15 g/100 ml and 11.6 g/100 ml
respectively. In case of Puntius ticto, the haemoglobin content in control
fishes recorded was 12.8 g/100 ml while in case of fish exposed to aldrin, the
haemoglobin content reduced initially on ten days exposure to 10.15 g/100 ml
and increased to 11.6 g/100 ml and 13.0 g/100 ml during twenty days and thirty
days exposure respectively. This trend was also observed with dieldrin in both
the fishes studied. Red blood cells were also counted in case of all the
pesticides and exposure periods with respect to Cyprinus carpio and Puntius
ticto. Irrespective of the species and pesticide, the RBC counts uniformly
showed decreasing trend with the increase in exposure period, while packed cell
volume, PCV(%) showed increasing trend with respect to increase in exposure
period in case of aldrin and dieldrin in both the fishes. But DDT, BHC and
chlordane showed decreasing trend in PCV(%) values with increasing periods of
exposure.
