Contamination due to Pathogens - Water Pollution
Sewage is a source of pathogenic viruses, bacteria, worms and other parasites. The extent of contamination by these pathogens in a water body is measured by counting harmless fecal coliform bacteria. Otherwise, it is not practical to routinely detect specific disease causing bacteria in water as it is a time-consuming and costly process. Therefore, an indirect easy method is used.
The non-pathogenic naturally occurring coliform bacteria found in human intestine and faeces are monitored. A high coliform count indicates fecal contamination, which is likely to contain more pathogenic agents of water-borne diseases.