Fluorine pollution and dental fluorosis in South Central Việt Nam
Đặng Trung Thuận, Đặng Trung Tú
Fluorine is a halogenous element which can become toxic when excessive, causing the so-called bone and dental fluorosis, a disease that takes place when the F content in living water is over 1,5 mg/l. Dental fluorosis is very common in the world, in many areas such as India, Bangladesh, China, Mongolia, Thailand. WHO’s standard of fluorine is 1,5 mg/l and Vietnamese standard is 1,0 mg/l. On the other hand, fluorine is also an important element for human bones, especially for developing permanent teeth i.e. the lack of fluorine is also harmful for human health.
Results of this study show that fluorine content in surface and underground water in some areas of South Central Việt Nam, such as Ninh Hòa District, Khánh Hòa Province, Đồng Xuân District, Phú Yên Province, varies from 0.1 to 11.5 mg/l; about 5.1 mg/l in fluorite mine water; especially in Triêm Đức and Phước Long thermal-mineral water the content of fluorine is up to 17 mg/l. Over 72% of well water samples exceeded the Vietnamese standard in terms of fluorine content. Dental fluorosis caused by an overdose of fluorine is widespread in Đồng Xuân’s teenage peoples. The number of patients and rate of serious disease are directly proportional to the fluorine content in living water from 2 mg/l and over. In the Đồng Xuân area, geologic structure, CaF2 mineral occurences and thermal-mineral water are the dominant factors and the main causes of dental fluorosis of local inhabitants.
There are some solutions to mitigate and prevent the dental fluorosis in Đồng Xuân area, but the best solution is the national support to supply clean water from western springs of this district.
Ngày nhận bài: 24/06/2008
Người biên tập: Quách Đức Tín