Mercury use by dentists hazardous

New Delhi: Use of mercury in dental sector, especially in the rural and unorganised sector in Delhi, is leading to mercury poisoning which has serious health impacts, say experts.

Dental amalgams, which are used to fill cavity caused by tooth decay, contain about 50 per cent of mercury and other toxic metals such as silver, tin, copper, zinc, etc., and are not safe.

While the presence of mercury in the patient leads to mercury poisoning, there is also a chance of mercury spillage in the clinic.

“Even a few drop of mercury is enough to pollute a huge kale. Similarly, if mercury is spilled in a clinic, it can be very dangerous both for the patients who visit that clinic and the staff working there,” said Lt. Gen. Vimal Arora (Retd), chief clinical officer of Clove Dental, a leading chain of dental clinics.

According to the United Nations Environment Programme (UNEP), about 260 to 340 tonnes of mercury is annually released into the environment globally from the use of dental amalgam, which is being used for over 150 years for tooth cavities.

Mercury is considered by World Health Organisation (WHO) as one of the top ten chemicals or groups of chemicals of major public health concern. Exposure to mercury — even in small amount — may cause serious health problems and is a threat to the development of the child in utero and early in life. It may have toxic effects on the nervous, digestive and immune systems, and on lungs, kidneys, skin, and eyes.

Lt. Gen. Arora said that awareness of health effects of mercury is not much among the general population. Dentists generally do not explain to their patients the impact of mercury filling on their health.

“Sometimes, patients insist on getting amalgams even if there are safer alternatives available like GIC and composites. They are a little expensive but patients should understand that the health hazard of mercury impregnated filling is far greater,” he said.

The Delhi government had banned dental amalgams and the use of mercury-based instruments like thermometers and blood pressure instruments in government hospitals. The step was reportedly taken because the hospitals had no idea how to deal with mercury spillage when instruments break.

“While the government hospitals are mercury free, many private clinics are also not doing dental amalgams due to aesthetic reasons. However, it is being widely done in rural areas like Azadpur by quacks and in the unorganised sectors,” said Dr Kavita Yadav, the programme coordinator of Toxics Link, an environmental research and advocacy organisation.

The NGO has undertaken a survey to estimate the usage of dental amalgam in the unorganised sector practicing dentistry in Delhi.

“It still exists in dental college curriculum and students, who have been trained in the practise, are still continuing it. We have approached Dental Council of India to remove it from the curriculum,” said Dr Yadav.