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Abstract
Health impact assessment on beach water sampling – A case study
Jeyanandhini V, Uma Mu
Student, B.E. GeoInformatics (III Semester), Dept. of Civil Engineering,
Anna University, Chennai, India
Email: jeyanandhini@yahoo.com,
muuma@rediffmail.com
Abstract
In day to day life due to various human activities the environment gets polluted. The degradation of the environmental elements has caused the people to take necessary preventive control measures. Hence there is a need to assess the cause for degradation and which in tern is affecting the ecology. The assessment of positive and negative effects of land, water, and air environment on the health of a person is called Health Impact Assessment. In this study an attempt is made to study the health impact assessment due to beach water pollution. A beach is a part of seashore, which is being used as a recreation spot by the people. There is not enough information available now to define the extent of beach pollution. Past monitoring studies have shown that beach pollution is usually infrequent or confined to local areas. Problems can develop in areas near pollution sources after a heavy rainfall or when a sewage treatment plant malfunctions. Pollution can also occur from disruption or damage to wastewater collection and treatment infrastructure due to severe natural events like hurricanes or flooding. The beach pollution level can be defined using GIS and Remote Sensing techniques and a comprehensive beach monitoring programs can be established.
Indian coastal waters are generally vertically well mixed except in isolated areas, which are under the influence of river discharges. Untreated effluent discharges from the industrial belts on the coasts impact the quality of near shore waters, but the effect generally gets diluted away from the mouth of the estuary, creek, or other such openings to the sea. Due to pollution in the beach water the quality of the beach water degrades. The severity of degradation depends on factors such as nature and quantity of wastes and flushing characteristics. The increase in the level of the pathogens is associated with outbreak of certain diseases. High levels of pathogens in recreational waters can increase human exposure to pathogenic bacteria, viruses and protozoans thus increasing the risk of illness. These disease-causing organisms may be present at or near the site where the polluted discharges enter the water. It can cause illness in bathers, include skin, ear, eye, nose and throat infections, as well as stomach disorders.
The objective of this proposed methodology is based on the need for improving public access to information about the quality of the water at their beaches and health risks associated with polluted water. It is to ascertain whether there is any impact on the health of the people. Decisions are to be taken based on the observations made and available data. The data is presented in such a way that the temporal and spatial nature of the problem can be brought out in a focussed way. The basic map layer is obtained from the optical remote sensing maps corresponding to the study area. The integration of all data sets is to be done in GIS and the location of sampling sites is based on the overlay analysis and theissen polygon proximity analysis. The purpose of using GIS is that maps provide an added dimension to data analysis.
Beaches are sampled along the beach and any source of pollution is also sampled. The water samples are collected along the shoreline. Water samples are collected in sterile bottles according to specific guidelines. The time, date, weather conditions and location of collection are recorded. The samples are then transported to the laboratory for analysis. Water samples are analyzed for indicator bacteria - which indicate possible pollution from numerous sources. They are called indicator bacteria because they are relatively easy to collect and analyze, and may indicate the presence of harmful viruses, bacteria or protozoa (also known as pathogens). The collected water samples are also tested for the conductivity, dissolved oxygen, temperature and turbidity.
If the bacterium is present in water at levels above certain limits then the water is polluted with storm water and/or sewage and may not be safe for swimming. The results of shoreline bacteriological testing are reviewed on a daily basis. The status of the beach waters can be indicated and included as open, closed, posted and advisory. In GIS different data layers can be combined along with statistical and other information in spatially referenced form. The functions provided by a GIS could allow analyses on these different data layers. Buffer zone is created showing the water pollution level and the extent of pollution. The interpolation of the results from the thiessen polygons is based on the geostatistics. The delineation of the safe zones is also based on the interpolation. When the level of the bacteria is high enough to cause illness, warning signs can be posted at the beaches.
The most effective way to reduce beach water pollution is through pollution prevention efforts. Everyone can help improve water quality at the beach no matter where they live, work or play. Runoff from anywhere in the County eventually ends up at the beach and with the runoff, all the bacteria, litter, oil or grease it picks up along the way. All the storm drains lead to the beach, not to a treatment plant!
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