Fluorine is found in abundance in nature. Fluorine, most important and active element of halogen group. The human body contains almost 96% fluoride in teeth and bones. The main function of fluoride is to increase bone density through mineralization and dental enamel formation. It strengthens teeth and thus increases the resistance of teeth to acid attacks. The other function of fluoride is to inhibit the growth of plaque, thus prevents tooth decay, reduces the acid-producing capability of teeth, protects the spleen and also increases the bioavailability of calcium.
The major sources are drinking water (0.5-0.8 mg/ L) and foods like sea fish, vegetables such as asparagus, cabbage, carrots, avocados, cauliflower, cucumber, dates, lemon grass, turnip, beet, sunflower seeds, garlic, tomatoes, spinach, green leafy vegetables, almonds, all sea vegetables, tea and cheese.
The guideline for fluoride content in potable / drinking water is 1 mg/L, this is the maximum level that our body can tolerate as excess fluoride is injurious to health. Fluorine is usually called as an element with a two-edged sword. Excess ingestion of fluoride is associated with skeletal and dental fluorosis and inadequate intake is associated with dental caries.
Fluorosis is the condition caused due to excess intake of fluoride. It is a crippling and painful disease. The major source of ingesting excess of fluoride in the body is through drinking water, food (agricultural crops), toothpaste. Other indirect sources of ingesting fluoride are dust and fumes from industries using fluoride-containing salt. The three types of fluorosis are:
• Dental fluorosis
• Skeletal fluorosis
• Non-skeletal fluorosis
Dental fluorosis mostly affects children by discoloring the teeth. Skeletal fluorosis affects the bones and joints of the body (neck, shoulder, hip, backbone and knee joints) that result in severe pain, rigidity or stiffness of joints. Non-skeletal fluorosis occurs long before the changes visible in teeth and skeletal bones. The symptoms of non-skeletal fluorosis are gastrointestinal symptoms which may overlap with other diseases thus leading to missed the diagnosis. It may affect men, women and children from all age groups.
Fluorosis is an endemic disease which is an important public health problem in 24 countries of the world including India. Within India, it is prevalent in 20 states out of 35 states and Union Territories. Maximum of people residing in tropical areas is affected by fluorosis as the groundwater contains a high concentration of fluoride. About 70 to 100% districts of Andhra Pradesh, Gujarat and Rajasthan, about 40 to 70% district of Bihar, Delhi, Haryana, Jharkhand, Maharashtra, Karnataka, Madhya Pradesh, Orissa, Tamil Nadu and Uttar Pradesh and 10 to 40% districts of Assam, Jammu and Kashmir, Kerala, Chattisgarh and West Bengal are affected by fluorosis.
The effect of fluorosis is irreversible, hence prevention of fluorosis is the appropriate solution using intervention measures.
The prevention of fluoride poisoning can be done in many ways:
• Use alternative water sources - One of the simplest intervention that can be undertaken is through the provision of surface water, rainwater and consumption of groundwater with low fluoride concentration
• Removing excess fluoride from drinking water - Sources that contain high fluoride content can be processed by de-fluoridation through flocculation, electrolyte de-fluoridation and adsorption. Reverse osmosis filtration of drinking water can be done to remove excess fluoride.
• Improving nutritional status of the population at risk - Providing health education and better nutrition are cost-effective intervention measures for preventing fluorosis. Avoid using products with high fluoride content, supari, tobacco and black/ red rock salt.
National Programme for Prevention and Control of Fluorosis (NPPCF) is the scheme was initiated in 2008-09 during the 11th five-year plan by the Indian Government in order to address the problem of fluorosis. The strategy of the NPPCF scheme:
surveillance of fluorosis in the community and school children;
capacity building (human resource) through training and manpower support;
establishing diagnostic facilities in the form of laboratory support and equipment including ion meter to monitor the fluoride content in drinking water and urinary levels;
management of cases with fluorosis through corrective treatment and surgery and providing rehabilitation;
providing health education for prevention and control of fluorosis.
Fluorosis is a major public health problem affecting millions of people. The permissible safe upper limit of the element in drinking water should be fixed to 0.5ppm (parts per million). One of the solutions, to prevent fluorosis, is supplying safe drinking water from the perennial river nearby the endemic areas and avoid wasting the resources on de-fluoridation plants.