Quantitative assessment of toxicity in the Shitalakkhya River, Bangladesh

Physicochemical parameters namely temperature, pH, salinity, EC, TDS, DO and COD were analyzed from October, 2012 to August, 2013. Toxic metals Cr, Cd, Ni, Cu and Zn were quantified during June, 2013. The observed parameters ranged as Temp. 20.5–31.3 °C, pH 6.9–8.0, salinity 57–582 mg/L, TDS 80–754 mg/L, EC 121–1167 μs, DO 0.5–3.5 mg/L and COD 80–480 mg/L. Toxic metal concentrations ranged as Cr 0.0371–0.1023 mg/L, Cd 0.0065–0.0152 mg/L, Ni 0.1441–0.513 mg/L, Cu 0.016–0.1434 mg/L, Zn 0.0481–0.13 mg/L. According to the statistical analysis pH, Salinity, EC, TDS and COD show positive correlations with each other and negative correlations with Temp. and DO. Toxic metals Cr, Cd and Ni show positive correlations among themselves and negative correlations with Cu and Zn. The hydrochemistry of the water body has revealed that the water is not safe for aquatic lives as well as human health. Also household, irrigations and industrial use without proper treatment are discursive.