Evaluation of Microbiological Quality of Municipal Supplied Water and its Impacts at Mirpur

Microbiological health risks are major concerning issue in all over the world. A study was conducted to evaluate the microbiological quality of municipal supplied water and its impacts at Mirpur, Dhaka. The selected water samples was examined for the concentration of Salmonella, Shigella, Citrobactor, Escherichia coli, Klebsiella, Aeromonas and Vibrio cholerae species in the Mods zone 4,Mirpur in Dhaka. In this regard, 20 water samples were collected from 10 selected pump station and 10 different consuming points that represent the total study area. The study also incorporates the evaluation of impacts due to the consumption of municipal water. A questionnaire survey was also conducted to have the public opinions regarding municipal water issues. 

The microbiological analyses were performed to trace the presence of indicator organisms and pathogens such as Escherichia coli, Salmonella, Shigella, Klebsiella and Aeromonas. According to the biochemical observation Escherichia coli 20%, Klebsiella75%, Salmonella 25%, Shigella 90% & Aeromonas 80% pathogenic bacterial were isolated among the 20 water sample. The presented data preferred that the quality of municipal supplied water are not safe for the consumer and also indicate that this water vernerable for diarrhea, dysentery, typhoid fever, shigellosis, salmonellosis, parasitic worm infection, hemolytic uremia syndrome, hepatitis, and gastroenteritis. questionnaire survey represented this feature among all the notified respondent diarrhoea 27%, 22.6% Typhoid, Dysentery 7% and 41.7 % affected by other types of water borne diseases. The overall study states that, the municipal water supplied by DWASA at MODS Zone 4 in Dhaka is not safe at all for domestic use, particularly for drinking purpose, and consumption of this highly contaminated water may be the prime cause of the water borne health hazards suffered by the peoples of Mirpur area. 

Keywords: water quality, evolution, impact, public health, microorganisms, miceobial contamination, consumer.
Water is the most vital element among the natural resources, and is crucial for the survival of all living organisms. The environment, economic growth and development of Bangladesh are all highly influenced by water–its regional and seasonal availability, and the quality of surface and ground water (UNEP, 2001). The quality of drinking water is closely associated with human health, and providing safe drinking water is one of important public health priorities. Estimated 80 per cent of all diseases and over one third of deaths in developing countries are caused by the consumption of contaminated water, and on an average as much as one tenth of each person's productive time is sacrificed to water-related diseases (UNCED, 1992). The quality of drinking water in Bangladesh is also at high risk. 

Over half of the people living in the large cities of developing countries are poor and live in informal settlements that lack a potable water supply (UN-HABITAT, 2003). Dhaka, one of the mega cities of the world, has a population of about 10 million in metropolitan area (BBS, 2008; BBS, 2009).About 19.4% of the total population of Dhaka city lives in the slum and squatter areas. Due to the faster growth of Dhaka city, people from all over the country come to Dhaka. Dhaka Water Supply and Sewerage Authority (Dhaka WASA) is the responsible body to supply water to this huge population. But the Dhaka WASA can only produce 1900 million liters of water per day against Dhaka city’s daily demand of 2200 million liters. About 87% of total water supply by Dhaka WASA comes from deep tube wells, and rest of the supply comes from surface water treatment. But as the water table of Dhaka city is being lowered day by day, it is high time to consider surface water treatment as the primary source.
Deteriorating water treatment facilities and distribution systems can pose a significant public health threat (Semenza et. al., 1998). The authors concluded with the epidemiological data that diarrhoeal diseases could be attributed to cross-connection between the municipal water supply and sewer due to leaky joints. Bangladesh has almost achieved accepted bacteriological drinking water standards for water supply, high rates of diarrheal disease morbidity indicate that pathogen transmission continues through water supply chain (and other modes). Waterborne diseases pose a risk to everyone. Some individuals are more sensitive to infection and suffer more pronounced symptoms. These sensitive sub-populations include infants, young children, older persons, and immuno-compromised individuals such as persons with HIV/AIDS and those undergoing chemotherapy.

Diarrheal disease is a major cause of morbidity and mortality in developing countries, including Bangladesh. Among 50 diseases prevalent in Bangladesh, 40 of them including diarrhea, dysentery, typhoid, parasitic worm infection etc. are related to contaminated food and water. Different strains of E.coli are responsible for a variety of diseases include diarrhea, dysentery, hemolytic uremia syndrome (kidney failure), bladder infections, septicemia, pneumonia, meningitis.Among the E.coli strains, the major pathotypes were enteropathogenic (EPEC) enterotoxigenic (ETEC) E. coli.Studies in Dhaka, Bangladesh have demonstrated that some 75% of diarrhoeal children and 44% of control children have an enteric pathogen in their stools. The major pathogens associated with diarrhoea being rotavirus, Cryptosporidium parvum and the following bacterial pathogens: Campylobacter jejuni, enterotoxigenic Escherichia coli, enteropathogenic E. coli, Shigella spp. And Vibrio cholerae O1 or O139 and to a lesser degree Aeromonas spp., Bacteroides fragilis and Clostridium difficile (Albert et al., 1999).

Cholera behaves slightly differently.Cholera behaves slightly differently. In warm regions of the world, the serogroups that cause epidemic cholera (Vibrio cholerae O1 and O139) are endemic in freshwater zooplankton (Colwell et al., 2003) and outbreaks occur in a regular seasonal pattern in developing regions in association with poverty and poor sanitation. The disease is characterised by devastating watery diarrhoea which leads to rapid dehydration and death occurs in 50–70% of untreated patients (Faruque et al., 1998). Cholera toxin (CT), which is responsible for the profuse diarrhoea, is encoded by a lysogenic bacteriophage designated CTX Phi, which probably results in a continual emergence of new epidemic clones. Hence, the ecosystem comprisingV. cholerae, CTX Phi in the aquatic environment and the mammalian host offers a complex relationship between pathogenesis and the natural selection of a pathogen (Faruque et al., 1998).

It is well known that the quality and safety of the drinking water continues to be an important public health issue ( Hrudey SE, Hrudey EJ, 2007 ), because its contamination has been frequently describe as responsible for the transmission of infectious diseases that have caused serious illness and mortality worldwide (Marshall JK et.al.,2006 ). Clearly, point-of-use water quality is a critical public health indicator (Reynolds et.al., 2007). The peoples of Dhaka city always depends on WASA for their water. For that reason this experiment is very much important to evaluate the quality of water sources in Dhaka city. 

Safe Water Supply and Development
Access to a safe water supply is one of the most important determinants of health and socioeconomic development (Cvjetanovic, 1986). For human consumption, water should be both safe and wholesome. Without ample safe drinking water, communities cannot be healthy (WHO, 2000). For a developing country like Bangladesh, where the majority of the people live below the poverty line, the provision of safe drinking water is considered “safe” when it is free from pathogenic agents, free from harmful chemical substances, and pleasant to taste i.e. ideally free from color and odor, and usable for domestic purposes (Park, 1997).