Application of global positioning systems and geographic information systems in drinking water defluoridation project in Liaoning province

Objective To establish information management systems of drinking water defluoridation project in water-related endemic fluorosis areas and investigate the status of drinking water defluoridation project in Liaoning, provide the basis for the development of control measures. Methods Global positioning systems (GPS)and geographic information systems(GIS) were used in the study in August 2006 - July 2008. Water defluoridation projects of 1234 in 48 counties(cities, districts) in drinking water type of fluorosis areas were positioned. Latitude and longitude, water samples, water fluoride content were collected or tested. GIS was used to establish information management system of water defluoridation projects. Results We have established information management system for the facilities of decreasing water fluorine in drinking water type of endemic fluorosis regions in Liaoning. One thousand two hundred and thirty four defluoridation facilities distributed in east longitude between 39.39° - 43.37°,north latitude between 119.25° - 125.50°, and altitude between - 6.60 and 801.14 meter in 48 endemic fluorosis counties in 13 cities. Nine hundred and twenty seven facilities for decreasing fluorine were able to supply water regularly, accounting for 75.1% of investigated projects;29 facilities was .not yet completely rebuilt, accounting for 2.4%;278 facilities(supply water for 344 villages) were out of order or discarded for 22.5% of investigated projects.Water fluorine contents of 63 facilities were greater than 1.2 mg/L, accounting for 6.8% of investigation project.Facilities working regularly and water fluorine was in accord with hygienic standard for drinking water facilities were 70.0%. Conclusions The establishment of Liaoning province defluoridation project information management system in the whole province of drinking water type of fluorosis areas provides scientific basis for accurate decision-making on prevention and control of the disease. Key words: Fluoride poisoning; Water; Engineering; Organization and administration; Global positioning systems; Geographic information system