Fluorosis: Epidemiology

Dipta K. MukhopadhyayAsst. Professor, Community Medicine

B. S. Medical College, Bankura

Fluorosis

• A crippling & painful disease caused by excess intake of / exposure to fluorides.

• Fluorides can enter through Water, Food, Toothpaste, Mouth rinses & Drugs.

• Fluoride dust & fumes from aluminium/ smelting industries.

• Fluoride in groundwater in India discovered in 1930 & first reported in 1937.

• Fluorosis can manifest as dental, skeletal, non-skeletal fluorosis.

Fluoride: Myth

• Fluoride inhibit enzymes breeding acid producing oral bacteria

• Fluoride ion binds with calcium ions making teeth enamel strong

• Harmful effect of Fluoride on other useful enzymes outweighs the benefit

• Excessive fluoride displaces calcium from tooth matrix• Chronic & cumulative exposure cause skeletal fluorosis

Magnitude

• Fluorosis- an important Public Health Problem in 24 countries including India.

• Fluoride belt extends from Turkey to China & Japan through Iraq, Iran & Afghanistan.

• Around 70 millions are affected

Indian scenario• Fluorosis is endemic in 20 states of India out of 35 states &

UTs.• 70-100% districts affected: AP, Guj, Raj.• 40-70% districts affected: Bih, Del, Har, Jhar, K’taka, Mah,

MP, Orissa, TN & UP.• 10-40% districts affected: Assam, J&K, Kerala, CG & WB.• 25 million people suffering from Dental/ Skeletal/ Non-

skeletal Fluorosis incl. 1 million incapacitating skeletal fluorosis.

• Nearly 66 million people consuming fluoride containing drinking water

West Bengal

• Fluorosis is a Public Health Problem in 9 districts of West Bengal.

• Worst affected districts: Purulia, Bankura.

• 17 blocks of Bankura are affected.

Agent• Primarily, Fluoride is present in drinking water• When F in water is more than 1.5 mg/L ,it is toxic

to health• Acidic pH promotes absorption in stomach• Ca in the diet reduces the absorption of F• Hard water rich in Ca reduces the F toxicity• Fresh Fruits and Vit.C reduces the effect of F• Trace elements like Molybdenum enhances the

effect of F

Host

• Dental Fluorosis seen in school going children• Skeletal Fluorosis seen in third and fourth

decade of life.• Males suffer more than females.• Migration influences the occurrence depending

on which way people migrate.• Illiterates suffer more frequently in the fluorotic

belts.• In aluminium ores mines, it is an occupational

health hazard.

Environment

• High Annual Mean Temperature• Low Rainfall• Low humidity• F rich Natural subsoil rocks• Vegetables from high F belts• Fluoridated tooth paste particularly when used

by children• Tropical climate• Developing Countries

Natural history• Dental fluorosis manifested due to exposure to

moderate amount of fluoride during 1-4 years• F ion replaces hydroxyl ion of tooth dentin• Hypoplasia & hypomineralization makes tooth brittle• Skeletal fluorosis occurs due to exposure to excessive

amount of fluoride for longer duration• Brittle bone, periosteal bone formation, narrowing of

medullary cavities, ossification of interosseus membranes & muscle tendons

• Skeletal fluorosis is consequence of exposure to > 14 mg/ day fluorine

Natural History

• Dental fluorosis has different grades:

• Questionable:• Very mild:• Mild:• Moderate:• Severe:

• Skeletal fluorosis has four grades:

• Pre-clinical: • Phase-I:• Phase-II:• Phase-III:

Community Fluorosis Index (CFI) is the way to measure community burden of dental fluorosis

Sources of Fluorides

• Drinking water: Particularly in tropics• Food contamination: - Black tea/ Rock salt/ Black salt. - Readymade masala /Street foods - Preserved foods- canned fish, fruit juice• Dental products: Toothpaste, mouth rinses• Drugs: Anti-depressants & Lipid lowering• Industries: Brick & Almunium• Fuel: high fluoride containing coal

Safe limit of Fluoride in water

• W.H.O. recommends the permissible limit of 1.5 mg/L.

• Bureau of Indian Standards made the safe limit of F- 1.0 mg/L.

• Countries like China, Thailand 7 West Africa made it 0.5mg/L.

Time-trend

• Quality of ground water depends on lithology & soil.

• Fluoride concentration increases through weathering of rocks & leaching of fluoride bearing minerals.

• Evaporation also increases fluoride concentration.

• Amount of fluoride increased with lowering of ground water level.

Interventions

• No definite treatment available.• Intervention 1: Stop fluoride entry- Safe drinking water: Surface water/ defluoridation- Avoid fluoride containing foods.- Avoid drugs and dental products.• Intervention 2: Promote adequate intake of essential

nutrients viz. Ca, Fe, Vit C, Vit E & other anti oxidants- Diet rich in cereals, fruits & vegetables- Pharmaceutical products

What to do ?

• Promoting better understanding of the problem• Advocacy & raising awareness of all stake holders• Strengthening the system of risk assessment• Provision & consumption of safe water & food• Reduction of exposure to fluorides from other

sources