Evaluation of Toxicity of Lead Salts (PbCl2 and PbNO3) Exposed Common Carp (Cyprinus carpio) in Two Seasons (Summer and Winter) of Different Temperature Conditions

Abstract

The main objective of the intended research was to ascertain the toxic effects of Lead salts (PbCl₂ and PbNO₃) in two seasons of varying temperatures in the Indian subtropical region of Bhopal. The toxicity test was carried out at concentrations of 250, 300, 350, 400,450, and 500 mg.l^-1 for the determination of LC 50 of PbCl₂ and PbNO₄ in summer at high temperature (HT) and in winter with low temperature(LT) conditions in common carp (Cyprinus carpio). The  LC 50 values for PbCl₂ for 24 hours in winter (LT) were 487.98 ± 1.17 mg.l^-1 and decreased to 466.66 ± 1.31 mg.l^-1, 436.11 ± 1.68 mg.l^-1, 416.49 ± 1.61 mg.l^-1, for 48, 72, and 96 hours respectively whereas in summer (HT) the LC 50 values were calculated as 396.83 ± 1.38 mg.l^-1, 359.42 ± 1.71 mg.l^-1, 345.95 ± 1.80 mg.l^-1 and 321.67 ± 1.24 mg.l^-1 for 24, 48, 72 and 96 hours respectively. The LC 50 values for PbNO₃ in winter (LT) were calculated as 427.76 ± 2.02 mg.l^-1, 400.13 ± 1.01 mg.l^-1, 373.42 ± 1.76 mg.l^-1, and 359.92 ±1.36 mg.l^-1 for 24, 48, 72, and 96 hours and in summer(HT) LC 50 values calculated as 357.93 ± 1.69 mg.l-1, 329.76 ± 0.83 mg.l^-1, 300.47 ± 1.41 mg.l^-1  and 274.29 ± 2.06 mg.l^-1 for 24, 48, 72 and 96 hours respectively. This study discovered that the counterions play an important role in toxicity due to which PbNO₃ toxicity was high as compared to PbCl₂ in both seasons as well effect of temperature in enhancing the toxicity of both Lead salts (PbCl₂ and PbNO₃) in summer was studied.

Keywords: counterions, LC 50, Seasonal temperatures, fish.