Bacterial and toxic pollutants in lakes of river Indus

摘要

Indus river water gets polluted through three sources viz., municipal wastewater, industrial wastewater and agricultural runoff through drainage structure. The lakes in Sindh (fed by the river Indus), constitute the important source of drinking water, recreation and fish, etc. and offer employment for many. A large number of chemicals that either exist naturally in the land dissolve in the water, or human excreta added due to human activity thereby, contaminating and leading to various diseases. In order to assess the microbial contamination, detection of pollutant indicator organisms (coliform group), using Coliform test was performed by Most Probable Number technique and total bacterial count by Pour Plate method. The level of various heavy metals (arsenic, calcium, cadmium, chromium, copper, iron, lead, mercury, potassium, magnesium, manganese, sodium, selenium & zinc) and electrolytes (Cl-1, HCO3-1) was monitored in water and fish meat samples collected from Haleji and Keenjhar lakes to assess the impact of toxic pollutants. Metal concentrations in water and fish samples were estimated by atomic absorption spectrophotometry. Total coliform organisms were found in both the lake water samples, exceeded in 38% samples than the acceptable limits, while total average aerobic bacterial count analyzed in both the lakes was 102 CFU/ml – 1010CFU/ml. Toxic chemical contaminants were estimated below the detection limit, while other several (essential) metal ions were found within the range set by WHO, except arsenic, cadmium and iron that exceeded slightly in 12.5% water samples. This study was designed to ensure the access of safe and potable water to urban & rural areas of Sindh. Further, the findings will help public/private enterprises and public health institutions to work for the people health friendly.