Microbes as Indicators of Water Quality and Bioremediation of Polluted Waters: A Novel Approach

Introduction

Water is the foundation of life. It circulates through the land just as it does through the human body, transporting, dissolving, replenishing nutrients and organic matter, while carrying away waste material. With two third of the earth's surface covered by water and the human body consisting of 75 percent of it, this is evidently clear that it is one of the prime elements responsible for life on earth. Our brain and blood are made of 95% and 82% water, respectively. An average adult body contains 42 litres of water and just a small loss of 2.7 litres can trigger signs of dehydration. To fulfill our basic requirement, we need safe, uncontaminated and clean water. Access to adequate potable drinking water supply is not only a basic need but is also a human right. Of all the problems we face today, those related to water are perhaps the most far reaching in their long-term consequences and the most difficult to tackle. If a state is unable to provide basic supply of safe and clean drinking water, sanitation and good hygiene services to its people, then the human right to water has been violated. Drinking water can be sourced from surface water or from ground water. Surface water includes rivers, lakes, ponds, streams and reservoirs. Ground water resources are wells, tube wells, springs, borewells, handpumps etc. Installation of communal facilities such as boreholes, standpipes or wells to provide water of better quality may not improve the situation because these facilities are usually located at some distance from the home and are prone for contamination during collection, transport and storage.

Drinking water as defined by Guidelines for Drinking is “water whose quality doesn’t represent any significant risk to health over a lifetime of consumption, including different sensitivities that may occur between life stages. It is estimated that poor water sanitation and lack of safe drinking water take a greater human toll than war, terrorism and weapons of mass destruction combined. In 2011, around 768 million people relied on unsatisfactory water supply having high levels of pathogen contamination.

More and More countries are facing water shortage and the condition is graver in the developing and third world countries of Asia, Africa where about 800 million people are living without access to safe drinking water. Potential of drinking water to transmit microbial pathogens to populations, causing diseases is well known in countries at all levels of economic development (Payment, 1997). Waterborne diseases account for an estimated 4.1% of the total DALY global burden of disease and cause 1.8 billion human deaths annually and 88% of that burden is attributable to unsafe water supply, sanitation and hygiene. Access to clean water is not just an issue for developing countries. Despite wealthy economies and access to proven drinking water-treatment technologies, significant outbreaks of waterborne intestinal disease have occurred in North America and Western Europe over the last 10–15 years. From 1970 to 2014, around 293 water borne outbreaks were reported in small non-community drinking water systems in Canada and USA (Pons, 2015).

Contamination of water resources by sewage, animal wastes, human excrement and storm water runoff presents greatest danger to public health associated with drinking water, and bacteriological testing continues to provide the most sensitive means for the detection of such pollution. In cities septic tanks, open dumps, improper constriction latrines and surface impoundments are the most common sources for sewage contamination, so that regular examination of water quality for the presence of pathogenic organisms, chemicals and other physical contents must be conducted to provide information on the level of the safety of water.