09 Dec 2009
Microbiology, Vectors and Control
Concerns have been raised about the safety of drinking water being provided for a large temporary community. The area is remote, rural, without proper sanitation and there are limited multipurpose water resources
How could you ascertain the safety of the water?
Potable water is fit for consumption by humans and other animals. Water may be naturally potable, as is the case with pristine springs, or it may need to be treated in order to be safe. There is a sufficiently high quality that allows consumption or use without risk of immediate or long term harm as recognized in www.water-technology.net/glossary/potable-water.html The most common and widespread health risk associated with drinking water is contamination; whether directly or indirectly, by human or animal excreta, principally faeces. If such contamination is newborn, and if those responsible for it include carriers of communicable enteric disease, some of the pathogenic microorganisms that trigger these diseases may be to hand in the water. Drinking the water, or food preparation by means of this resource, may cause the manifestation of new cases of infection. Faecal contamination of drinking water is one of copious faecal-oral mechanisms by which transmission from person to person or from animals to people can transpire. Other pathogens instigate infection when contaminated water is draw on for bathing or recreation. This entails water contact, rather than oral ingestion. For these reasons it is essential that the safety of the water sources must be ascertained. Aquatic insects and other invertebrates, in view of the fact that they populate within the vicinity of the water, are most likely the easiest and cheapest way of ascertaining an approximate concept of the water quality. They depend on clean, uncontaminated water to live in, and if organic effluence enters the system, insects invariantly are first to disappear. These are entitled "Indicator organisms". Utilising insects to conclude the water quality is based on the fact that every species has a certain range of physical and chemical conditions in which it can survive. Some organisms can survive an assortment of conditions, and more tolerant of pollution. Others are very sensitive to alterations in conditions and are "intolerant". Water quality can be determined by comparing the number of pollution-tolerant organisms with the number of pollution intolerant species. It is imperative to note that pollution tolerant organisms can be found in both polluted and unpolluted waters. This can be employed as a criterion to focus on assessing the more suitable water sources, conserving resources and time. Preliminary tests would be executed on a source with and without insect life and then evaluated. As an example, if there were symptoms of pollution in the water source that had no insect life then all labours would be concentrated on those with insect life. This would be accompanied by further testing on this category of water source that is predetermined by the criterion of indicator organisms found within www.epa.gov/bioiweb1/html/lifecycle.html Faecal pollution by man and animal is capable of causing health implications from mild eye and ear infections, to diarrhoea and serious infectious illness including typhoid. The second main faecal pollution issue is that sewage is prosperous in nutrients and organic matter which causes detrimental changes to bottom sediments and contributes to eutrophication. The purpose of taking into account insect life as a preliminary search parameter is that the process of eutrophication can be initiated by the egress of faeces, human or otherwise. The enrichment of organic matter promotes excessive plant growth and decay, favoring simple algae and plankton, which reap the benefits first over other more complicated plants. This process causes an...
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