Fluorosis, thanks to contaminated groundwater, is more an issue in Tamil Nadu than is generally acknowledged. In mild forms, it appears as discolouration of teeth, but it can even affect the skeletal structure. In areas where fluorosis is prevalent, our reporter finds that people cannot even afford a session with the dentist
Lakshmi’s front teeth are marked by distinct brown lines. “I got these stains when I moved here after my marriage. My son also has these,” says the resident of Vadapatti village in Sivakasi. She is one among the hundreds in her village affected by dental fluorosis.
Dental fluorosis is a defect in the tooth enamel caused by excessive exposure to high concentrations of fluoride. Brown, grey and black teeth patches and pits are common among the people living in this area.
In its mild forms, fluorosis appears as unnoticeable, tiny white streaks or specks on the teeth while permanent tooth discolouration or brown markings can be seen in severe cases. The tooth becomes pitted, rough and hard to clean. The spots and stains may darken over time.
Dental fluorosis is not treatable and the stains are permanent. The severity depends on the amount of fluoride exposure, age, individual response, weight, degree of physical activity, nutrition etc. Excessive consumption of fluoride-contaminated water over time can also lead to skeletal fluorosis.
According to World Health Organisation guidelines, the fluoride concentration in drinking water should not exceed 1.5 mg/l.
The latest guidelines from the Bureau of Indian Standards (BIS) suggest that the desirable fluoride limit in water used for drinking and cooking purposes is 1 mg/l, and the permissible limit in the absence of an alternate source is 1.5 mg/l. Reports show that Sivakasi (Andiapuram 1.6, Mathiaseni 1.7, Sukkiravarpatti 1.5, Nagalapuram 2.0, Injar 2.2) has a high fluoride amount of 2.2 mg/l.
Fluorosis is a severe public health problem in India. Some 35 million people, including children, are presently affected by fluorosis and 66 million are at risk of developing the disease.
The main source of fluoride in groundwater is the rocks that are rich it. The most seriously affected States are Andhra Pradesh, Punjab, Odisha, Haryana, Rajasthan, Gujarat, Tamil Nadu and Uttar Pradesh.
The rock profile in Sivakasi, an industrial town in Virudhunagar district, located east of the Western Ghats, consists of charnockite, quartzite, pegamatite, laterite, and sandstone. Alluvial soil in this area acts as a good aquifer along the Vaippar and Gundar river beds, which are major sources of water supply to the villages. The borewells are drilled to a depth of 40-70 m.
Due to the nature of the rocks and weathering, fluoride ions leach out into groundwater aquifers. The dissolution of apatite or fluorapatite minerals from charnockite rocks releases the flouride into groundwater.
In many small villages like Viswanatham, Vetrilaiyurani and Singamala Nachiarpuram in the district, it is common to meet people with dental stains. People in the age group ranging from two to 80 years have the stains.
“Women from these villages usually come to me before their wedding. They want the stains removed. But a simple scaling doesn’t do the job. We have to do an intentional root canal treatment and make them wear an artificial crown. It is a costly procedure,” says A.C. Thilagar, who has been treating such cases in and around Sivakasi for the past 40 years.
“We are three sisters and one brother. All four of us have the stains,” says Divya, who had come to Dr. Thilagar to pull out one of her teeth that had become completely brown due to extreme fluorosis.
“I can’t afford to water cans. We take water from the borewell pipe at the end of this street. The foreman at the fireworks factory says my teeth are brown because of consuming borewell water. I don’t believe it. My parents and brother have this too,” says Dhanam from Vetrilaiyurani. ”How can water stain teeth?” she asks and smiles at the camera.
In Kalathupatti, a hamlet with about 1,000 inhabitants in Natham taluk, Dindugul district, children from five years of age have brown teeth. “My daughter and I have identical brown marks, like a family trait,” laughs Ratna, a villager. They are used to it now, and, unaware of the health implications of the disease, pose for photographs, their teeth brown and brittle.
“After a point, the teeth start becoming brittle. Most people think these are like simple stains and can be removed. But the procedure is different. We have to bleach [the teeth] and in extreme cases, pull out the teeth and give a metal and ceramic crown,” explains A.T. Gayathri, a dentist in Dindugul, who gets most of her cases from Natham taluk.
Dental stains are common in Murugathooranpatti, a hamlet in Nilakottai taluk in the same district. Nilakottai is reported to have a high fluorine content of 3.2mg/l.
“He ate raw bananas, that’s why he has these stains,” says 10-year-old Aravind, making fun of his friend Dinesh. Aravind has a milder form of fluorosis with white spots, while Dinesh’s teeth have brown lines.
In search of solutions
“With assistance from the Tamilnadu Water Supply and Drainage Board (TWAD), the chemistry department of Gandhigram University has installed about 16 de-fluoridation plants in areas where the fluoride content in groundwater is greater than 1.5mg/l. The units were handed over to local body authorities. Thereafter, it has been under their care,” says Anitha Pius, professor at the department.
Not everyone is putting the plants to good use, however.
“The researchers from Gandhigram University tested our water and said it has high fluorine. They also set up some kind of treatment plant. We are scared to use the water from it. We use the water from the borewell in the next street,” says Selvam from Kalathupatti. “My cousin went to a dentist in Dindugul and removed the brown colour, but I can’t afford that,” he adds.
Tapping surface water
Tapping surface water sources is an effective way to fight fluorosis.
“The TWAD board has already executed two projects in Virudhunagar. The western part of the district will soon be provided water from the Tamirabarani. The project will be completed by December 2017. ?234 crore has been allocated by the government to provide water for 755 rural habitations. The municipal administration will be in-charge of the overhead water tanks and the people will be instructed not to drink groundwater,” says N. Rajasekar, executive engineer, TWAD, Virudhunagar (Project Division).
Officials from TWAD, Chennai, confirmed that 75% of the work has been completed in Virudhunagar and a project is under execution in Dindugul. The latter, costing ?636 crore, will be completed in September and 1,276 habitations in the district will be provided safe drinking water.
In Dharmapuri and Krishnagiri, the implementation of the Hogenakkal Water Project has not helped much since the water supply is not regular and the fluoride content in the water consumed is as high as 6mg/l, says M. Shanker, team leader, Development Education and Environment Protection Society (DEEPS), who has been working in the district for the past 20 years on fluoride mitigation projects. “If no other alternative water source is available, the government can set up de-flouridation plants [Nalgonda-based drum sets and activated alumina] like the ones used in Rajasthan,” he adds.
“An integrated approach is required to combat fluorosis. Nutritional supplements and adequate intake of foods rich in calcium, vitamins C & E and antioxidants, along with consuming safe drinking water, is necessary. People residing in the endemic areas should be made aware of the adverse health impacts of excessive fluoride consumption,” explains Sunderrajan Krishnan, executive director, India Natural Resource Economics and Management (INREM) Foundation, who works with FluorideIndia network and helps in spreading fluorosis awareness in Gujarat.
*Original article online at http://www.thehindu.com/news/cities/chennai/hazard-of-groundwater-use-disease-of-ignorance/article19333615.ece