A recent research by the Public Health Laboratory shows that inadequate Fluoride content in drinking water could be attributed as the reason for high number of tooth decay (cavity) cases in the country.
Fluoride is a chemical that is known to protect teeth.
The findings of the Water Quality Section, Public Health Laboratory (PHL) under Ministry of Health (MoH) on Fluoride Mapping of Drinking Water in the Urban and Semi-Urban Areas in Bhutan, 2012 revealed that the fluoride content in the drinking water of urban and semi-urban areas was way below WHO recommended standards that is 0.5mg/l.
PHL’s Chief Sonam Wangchuk said the potential source of Fluoride in the country is either from vegetables or water.
He said “In Bhutan Whatever vegetables we grow, the Fluoride is washed away from the soil by the monsoon rain and even if we grow vegetables in this terrain there is no Fluoride.”
Although vegetables may contain Fluoride, it is not optimum and therefore people don’t get adequate amounts through what they eat or drink. This is a problem because it leads to dental caries (tooth decay or cavity).
“There could be other factors as well but this could be one of the factors of dental caries,” said the PHL Chief.
He said, “Since the water is the main source, in our study we have found that the Fluoride content is less than WHO recommended standards in both dry as well as wet season although the average concentration in the wet season is higher than the average concentration in the dry season.”
The water study is being conducted in all 20 districts in the country in urban and semi-urban towns that have large community water supply systems in place.
Except for the samples from the four sampling sites that is Thimphu (Jungshina), Trashigang, Pemagatshel and Samdrup Jongkhar, Fluoride level in all other samples is found higher in wet season than those of dry seasons.
PHL Chief Sonam Wangchuk said study was done in both the seasons because during wet seasons, due to water flushing there is some washing out of soil “but our study found out, there is not much difference between the seasons.”
He said, “We have proven that water source in Bhutan or the vegetables grown in Bhutan would not have adequate fluoride in it. That’s why dental caries especially in children is due to lack of adequate Fluoride.”
Considering the WHO-recommended Fluoride level in drinking water, all the drinking water sources in the urban and semi-urban areas in Bhutan, have low Fluoride concentration.
The WHO recommends a Fluoride level of 0.5mg/l to 1.0 mg/l with a maximum allowable limit of 1.5 mg/l. Bhutan does not have a standard and follows the WHO guidelines.
High concentration of Fluoride in potable water results in teeth mottling and skeletal fluorosis while low levels result in diminishing caries-reduction. Therefore, many countries have established the optimum Fluoride level (standard) in the drinking water whereby the water service providers are required to treat the water to maintain the standard.
The report states, in Bhutan for many years, dental decay is seen as a major oral health problem among children as well as the adults. Dental caries also remains a major public health problem in most high income countries affecting 60-90% of school going children and the vast majority of adults. Also, it is the most prevalent oral disease in several Asian and Latin American countries.
The incidence of dental caries in general population in Bhutan is 5,561 cases per 100,000. The Annual Health Bulletin (AHB), 2012 shows 38, 929 dental caries cases in 2011.
In the past three years AHB shows 30,328 cases in 2008 which later increased to 30,356 in 2009 and then increased to 36, 456 cases in 2010.