Fluoridated salt used in global fight against caries
Bridgeport, Conn., USA: Most dental professionals in the United States are unaware that globally, fluoridated salt has significantly reduced the caries rate in many developing nations. Full effectiveness relies on the salt reaching consumers by several different channels. Fluoride salt can be used in homes, but it is also distributed to restaurant kitchens, school canteens, hospitals, bakeries and large bread factories.
Fluoridation of salt destined for human consumption has been used in Switzerland since 1955. Since 1986 an increasing number of countries, now approximately 15 and mainly in Europe, have adopted salt fluoridation strategies.
Farmers in Southeast Asia make salt on fields that have been used for centuries. The brine (saltwater) is poured on fields and left for several days until much of the water has evaporated and salt crystals remain. The crystals are then scraped up and carried to warehouses, typically constructed of wood, which hold an average of 2,000 tons of salt. In large production plants where continuous processing of salt is common, the procedure is to spray a dosed concentrated fluoride solution through a nozzle onto the salt passing on the conveyor belt below. In some countries one-ton mixers (customarily used for mixing animal feed) are used to add the fluoride.
The University of Health Sciences Laos launched an iodine fluoride program this past April. Health officials have estimated that the addition of iodine and fluoride would contribute to the prevention of iodine deficiency disorders and prevent dental caries.
Aide Odontologique Internationale (AOI) is a non-governmental organization working with dentists in Laos and Cambodia. In developing nations, AOI seeks to improve oral health by working concurrently with ministries of health, the World Health Organization and UNICEF.
Iodine is an essential micronutrient that is necessary for the normal functioning and development of the brain and body. Children born into households where iodized salt is not consumed are at risk of developing mental and physical disabilities.
Major challenge in Cambodia
Dental caries is a major public health threat in Cambodia. Unfortunately, there are serious issues of quality control and sustainability that, to date, have prevented the availability of fluoridated salt to Cambodian consumers. One study, found the Cambodian childhood caries experience to be very high. Only 36 percent of children aged 1–4 years and 4 percent of those aged 5–6 years were caries free. Only 15 percent of mothers reported bottle-feeding, but 70 percent of such mothers used sweetened canned milk in the bottle. Oral hygiene was rated as poor in 80 percent of children and only 10 percent were reported to use a toothbrush. Forty three percent of children were reported to have experienced toothache, but only 5 percent had been to a dentist.
Dr. Francois Courtel, AOI director in Cambodia, said, “In Cambodia, a feasibility study in 2010 showed that the situation was not favorable for starting salt fluoridation. The main association of salt producers is not willing to start fluoridation because they have to deal with iodine and realize that it is more costs for them. There are many small artisanal producers and boilers; the technology they use for mixing salt and iodine is not safe and professional. It was decided by the ministry of health not to start introduction of fluoride at this time. Maybe in the future, if the situation improves, that will be reconsidered.”
Fluoridation of water supplies has proven to be an effective preventive measure for dental caries. Many developing countries in the Americas have multiple water systems rather than centralized sources. Struggling economies may not permit the viable application of this fluoridation approach.
Some of the highest dental caries prevalence in the world is evident in the Americas. Fluoridated salt was considered as a potential solution because of the urgent need for dental caries prevention in millions of people with limited access to routine dental services.
Early success in Columbia
A fluoridated salt trial was initiated in Columbia (1963) and upon successful completion with preventive results comparable to water fluoridation, the approach was introduced to other countries and was supported by resolutions of the World Health Organization, the Pan American Health Organization, regional health groups and the World Dental Federation. The procedures for addition of fluoride were comparable to those for iodization. Result, based on addition of F ion at 200–250 mg/kg salt, indicated caries prevalence reductions in 12 year olds ranging from 84 percent in Jamaica and 73 percent in Costa Rica to 40 percent in Uruguay at an average cost of US$0.06/capita/year.
Prior to establishing a salt fluoridation program, health workers determine if there is any naturally occurring fluoride in the water supply via sample collection. In addition to maintaining important sanitary considerations, the consistency of proper levels of fluoride added to the salt must be monitored as well. Sodium fluoride or potassium fluoride is added in accordance with whether a dry or wet production method is used. Standardized epidemiological surveillance is needed after the fluoridated salt is made available to the public. Both open-mouth and urinary fluoride evidence has been used in the past to monitor a program’s safety and efficacy.
We can conclude that individuals in developing nations are at a far greater risk for debilitating dental disease then they are for fluorosis after the implementation of fluoridated salt usage. Salt is a naturally occurring part of our human existence. It is essential to our health and development. Universally consumed, its risk of overdose is minimal as everyone eats a predictable amount. Additional additives are being looked at by the World Health Organization to prevent malaria and other infectious disease in impoverished nations.
When addressing the problem of increasing dental disease in developing nations, it is obvious that strengthening the local health structure is required first. We then need to ask ourselves how to have the maximum effect in these low-income countries. Fluoride toothpaste, rinses, varnish applications and supplements may have proven themselves in the West, but they are not universally affordable.
While Laos has seen fluoridated salt production for a year now, its neighbor Cambodia has not yet found the financial means to assist in reducing the suffering from dental disease. The rural children of Cambodia are extremely poor. In this country, one in 14 individuals is an orphan. There is little food to eat, and there is a complete lack of basic sanitation, medical/dental services and education. Child exploitation and child labor are the norm.
Fluoride salt production assists sustainable economic development and is an effective management of natural resources. When I travelled from Thailand to Cambodia the difference in household wealth was hugely apparent in the rural areas. My cheery ‘tuk tuk’ (taxi driver) spoke enthusiastically about how oil was just found off the Cambodian shore. He was gleeful that soon prosperity would be coming to his nation. My thoughts turned to all the sovereignty and political disputes over islands in the South China Sea. I hoped he was right. I prayed he was right. But I would rather have taken what he said with a grain of fluoridated salt.
Note: This article first appeared in Hygiene Tribune U.S. Edition, Vol. 5 No. 2, February 2012. A complete list of references is available from the publisher.