Risk Assessment of Nitrate and Coli Form in Public Drinking Water at Chiangrai Province

Abstract

Data from routine services on water quality analysis by Regional Medical Science Center 1/1 Chiangrai revealed that the quality problems were related to the contamination of nitrate and coliform bacteria which were used as indicators for water purity and health risk. The objective of this study was to assess the magnitude of contamination through the application of GIS quantum program and calculated the ingestion of nitrate and coliform bacteria based on daily intake data collected by using questionnaire. Altogether 44 water samples were collected; and the levels of nitrate and coliform were analyzed by ion chromatography and MPN method respectively. It was found that 20.45% of water samples has high nitrate level and 36.36% had coliform contamination which did not pass the Ministry of Public Health standard drinking water criteria. Based on the GIS Quantum program, higher risk of nitrate was identified at Maelaw and Weingchai districts; and coliform at Mae Law, Padead and Doiloung districts. However, based on correlation analysis, such contamination was still not harmful to human health. Nevertheless, routine water purification was recommended.