Fluorosis

Ravi Rohilla

Community Medicine

PGIMS Rohtak

Contents• Introduction• Magnitude of fluorosis

– World and India• Epidemiological triad• Permissible limits of fluoride• Clinical picture and tests• Treatment and prevention• Community Fluorosis Index• Methods for removal(De-fluoridation)• Nalgonda technique• References

What is Fluorosis

• Fluorosis is a disease caused by deposition of fluorides in the hard and soft tissues of the body.

• It is not merely caused by excess intake of fluoride but there are many other attributes and variables which determine the onset of fluorosis in human population.

• It is usually characterised by discoloration of teeth and crippling disorders.

• Worldwide in distribution• Endemic in 22 countries • Asia (India and China are worst affected)• Mexico in North and Argentina in Latin America• East and North Africa are also endemic

Magnitude of Fluorosis

Geographical area with high natural fluoride levels

• In some areas, skeletal fluorosis is endemic. While fluorosis is most severe and widespread in the two largest countries - India and China.

• UNICEF estimates that "fluorosis is endemic in at least 22 countries across the globe. The total number of people affected is not known, but a conservative estimate would number in the tens of millions."

• WHO estimated that 2.7 million people in China have the crippling form of skeletal fluorosis. In India, 20 states have been identified as endemic areas, with an estimated 60 million people at risk and 6 million people disabled; about 600,000 might develop a neurological disorder as a consequence.(1999)

• Fluoride levels in surface waters vary widely according to geographical location and proximity to emission sources but are generally low, ranging from 0.01 to 1.5 mg/L.

• Concentrations in seawater commonly range from 1.2 to 1.5 mg/L. Freshwater concentrations are usually lower than seawater ranging from 0.01 to 0.3 mg/L.

• Factor known to influence water fluoride levels include the presence of natural rock rich in fluoride (such as granites and sediment of marine origin).

• Additionally, elevated inorganic fluoride levels are often seen in regions where there is geothermal or volcanic activity.

• Fluorosis is an endemic disease prevalent in 20 states out of the 35 states and Union Territories of the Indian Republic.

• Rajasthan and Gujarat in North India and Andhra in South India are worst affected.

• Bihar, National Capital Territory of Delhi, Haryana, Jharkhand, Karnataka, M.P. and Maharashtra are moderately affected.

• T.N., W.B., U.P., Bihar and Assam are mildly affected.• Throughout India fluorosis is essentially Hydrofluorosis

except in parts of Gujarat and U.P. where industrial fluorosis is also seen.

Fluorosis in India

Fluorosis in HaryanaFluoride (>1.5 mg/l)----

Bhiwani Mahendergarh

Faridabad, Panipat

Gurgaon, Rewari

Hissar, Rohtak

Jhajjar, Sirsa

Jind, Sonipat

Kaithal, Kurukshetra

Fluoride: good or bad for health?

• Fluoride was first used to fight dental cavities in the 1940s, its effectiveness defended on two grounds:

1. Fluoride inhibits enzymes that breed acid-producing oral bacteria whose acid eats away tooth enamel. This observation is valid, but some scientists now believe that the harmful impact of fluoride on other useful enzymes far outweighs the beneficial effect on caries prevention.

2. Fluoride ions bind with calcium ions, strengthening tooth enamel as it forms in children.

• Many researchers now consider this more of an assumption than fact, because of conflicting evidence from studies in India and several other countries over the past 10 to 15 years.

• Nevertheless, agreement is universal that excessive fluoride intake leads to loss of calcium from the tooth matrix, aggravating cavity formation throughout life rather than remedying it, and so causing dental fluorosis. Severe, chronic and cumulative overexposure can cause the incurable crippling of skeletal fluorosis.

Epidemiological triad

• Primarily it is Fluoride which is present in drinking water• When F in water is more than 1.5 mg/litre, it is toxic to

health• pH in terms of alkalinity of water promotes the absorption

of F• Calcium in the diet reduces the absorption of F• Hard water rich in Calcium reduces the F toxicity• Fresh Fruits and Vit.C reduces the effect of F• Trace elements like Molybdenum enhances the effect of

F

Agent factors

Sources of fluoride for humanexposure

Main sources of fluoride :•Water•Food•Air•Medicament•Cosmetics

• In School going children seen as dental fluorosis.• In third and fourth decade of life seen as Skeletal

Fluorosis.• Males suffer more than females.• Migration influences the occurrence depending on

which way people migrate.• Illiterates suffer more frequently in the fluorotic belts.• Where aluminium ores are mined,it is seen as

occupational health hazard.

Host Factors

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

children• Tropical climate• Developing Countries

Environmental Factors

Permissible limit of Fluoride by various organisations

Clinical Picture

• Dental Fluorosis in Children

• Skeletal Fluorosis in Adults

• Non Skeletal Fluorosis

Dental Fluorosis• Children living in high fluoride zone are bound to get

dental discoloration which may be seen even in deciduous teeth.

• Initially glistening white teeth become dull and yellow-white spots appear on the surface of teeth.

• Gradually these spots turn brown and presents itself in brown streaks which are closer to the tip of the teeth.

• In late stages the whole teeth become black. Teeth may be pitted or perforated and may even get chipped off.

Skeletal Fluorosis

• It affects young as well as old. The symptoms include severe pain and stiffness in the backbone, joints and/or rigidity in hip bones.

• X-ray examinations of the bones reveals thickening and high density of bones. In some patients with calcium deficiency, osteomalacia type changes are seen.

• Constriction of vertebral canal and intervertebral foramen - pressure on nerves leads to paralysis.

Photograph showing skeletal fluorosis patient

Radiograph of a patient of skeletal fluorosis

Non-Skeletal Fluorosis• There are convincing evidence of involvement of

skeletal muscles, erythrocytes, G-I mucosa, ligaments and spermatozoa on consuming more than optimal intake of fluorides. Detection of Fluorosis at early stage is possible by understanding the soft tissue manifestation.

• In the fluorosed muscles, actin and myosin filaments are destroyed and mitochondria lose their structural integrity thereby providing evidence of depletion of muscle energy.

• The erythrocyte membrane loses its calcium content in presence of high fluoride.

• Non-ulcer dyspeptic complaints are manifested by consuming high F in water and food.

• Infertility due to oligospermia and azoospermia is commonly seen in fluorotic belts.

Tests for Skeletal Fluorosis• Affection of the joints can be ascertained through simple

tests which can be carried out at the bed-head side and in the field:

• COIN TEST: The subject is asked to lift a coin from the floor without bending the knee. A fluorotic subject would not be able to lift the coin without flexing the large joints of lower extremity.

• CHIN TEST: The subject is asked to touch the anterior wall of the chest with the chin. If there is pain or stiffness in the neck, it indicates the presence of fluorosis.

• STRETCH TEST: The individual is made to stretch the arm sideways, fold at elbow and touch the back of the head. When there is pain and stiffness, it would not be possible to reach the occiput indicating presence of Fluorosis.

Dental Fluorosis Treatment• Tooth whitening - For mild fluorosis cases.• Composite bonding- For severe cases of fluorosis• Porcelain veneers- provide excellent cosmetic

results.

Prevention of Fluorosis

• Since the major source of fluoride is drinking water, de-fluoridation is the best preventive measure which can be carried out at domestic as well as community level.

• Nutritional interventions like high intake of vitamin C and Calcium also helps reduce the problem.

Food items to be avoided Rock salt Black salt (Kala-namak) Tea (without milk and with lemon) Salted snacks smeared with black salt viz. 

Dalmoth, Channa dal

Pickles smeared with black salt Masala's smeared with black salt

Chana masala, Jal jeera masala

Fruit juices (Preserved) Churans (Hajmola, Hingoli, Satmola)

Community Flourosis Index• W.H.O. Monograph on Fluoride and Human Health

(1970) has enumerated the use of Community Fluorosis Index in determining the optimal Fluoride Intake.

• The Community Fluorosis Index (CFI) is a way of measuring the burden of dental fluorosis in a population. Instead of measuring the overall prevalence of fluorosis (i.e., what percentage of people have fluorosis), it takes into account the severity of the fluorosis that is occurring. The CFI is thus a measurement of both prevalence + severity.

An individual's fluorosis score is based on the most severe form of fluorosis found on two or more teeth.

Community Fluorosis Index• The CFI is calculated based on the following point scale for the

different categories of dental fluorosis:

• Questionable Fluorosis = 0.5 points

• Very Mild Fluorosis = 1 point

• Mild Fluorosis = 2 points

• Moderate Fluorosis = 3 points

• Severe Fluorosis = 4 points• After determining how many children have these types of fluorosis,

the points are added up and divided by the number of children examined.

Scores and their significance

Range Significance of scores

0.0-0.4 Negative

0.4-0.6 Borderline

0.6-1.0 Slight

1.0-2.0 Medium

2.0-3.0 Marked

3.0-4.0 Very Marked

Only when the CFI value is greater than 0.6, Fluorosis is considered to be a public health problem in that area

Methods for removal of Fluoride

• Bone charcoal, • Contact precipitation • Nalgonda technique, • Activated alumina

and clay

-appropriate in developing countries.

Advanced treatment technologies, e.g.•Reverse osmosis, •Electrodialysis and distillation, plus •Methods based on patented media and natural media

• Boiling Water :This will concentrate the fluoride rather than reduce it.• Freezing Water: Freezing water does not affect the concentration of fluoride.

Fluoride removal technologies and their suitability

• Precipitation methods are commonly used for de-fluoridation.

• Lime treatment, routinely used for hardness removal can remove F particularly when water is having high Mg hardness.

• Alum is used at domestic level in high doses to remove the F.

• In India scientists have developed a method known as Nalgonda technique in which, based on the amount of F in drinking water and alkalinity of the Water (expressed as mgCaCO3), amount of Alum to be mixed with water is calculated.

Nalgonda technique• Adapted and developed in India by the National

Environmental Engineering Research Institute (NEERI) and developed to be used at both the community and household levels.

• The process is aluminium sulfate based coagulation-flocculation sedimentation, where the dosage is designed to ensure fluoride removal from the water

• Aluminium sulfate, Al2 (SO4)3 18H2O, is dissolved and added to the water under efficient stirring in order to ensure initial complete mixing.

• Aluminium hydroxide micro-floccules are produced rapidly and gathered into larger easily settling floccules.

• Thereafter the mixture is allowed to settle. During this flocculation process many kinds of micro-particles and negatively charged ions including fluoride are partially removed by electrostatic attachment to the floccules.

The fill and draw type Nalgonda technique for domestic and community defluoridation

References• WHO Monograph “Fluoride in Drinking-

water”(2006)

• Central Ground Water Board(website)

• Bureau of Indian Standards(BIS)

• UNICEF report on Fluorosis in India(1999)

• http://www.fluorideandfluorosis.com/