Passage of the global mercury treaty now known as the Minamata Convention was an amazing achievement. It’s not even close to perfect, of course. Perhaps its most significant shortcoming is that it doesn’t require an actual phase-out of dental amalgam. The way it’s written, as we’ve noted before, a country doesn’t need to take any actual steps toward going mercury-free. Largely symbolic actions can suffice.
But in one signatory country, there’s a strong push being made for an immediate ban: the Philippines. The effort is being led by the nonprofit environmental group Ban Toxics, whose recently released study on mercury exposure in dental clinics provides plenty of reason why a total abandonment of amalgam is needed right here and now.
The study – conducted in conjunction with IAOMT-Philippines, the World Alliance for Mercury-Free Dentistry and Asia Center for Environmental Health – was as simple as the results were powerful: measure mercury vapor concentrations at typical points of exposure.
It was found that mercury concentration values varied from 967ng/m3 to a high of 35,617ng/m3—the majority of which were at levels beyond recommended reference standards such as the Agency for Toxic Substances and Disease Registry (ATSDR) action level of 1,000 ng/m3. Some areas posted a concentration of >10,000 ng/m3, which is considered as the evacuation alert level by the US EPA.
The group is calling for dental schools to exclude the required use of amalgam – a change “in line with the move to phase-out mercury use in the health sector by 2016.”
The dean of the University of the Philippines’ (UP) College of Dentistry, Dr. Vicente Medina III, however, described the group’s claim as “scare tactics.”
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He said the UP College of Dentistry was “strongly opposed” to proposals to ban the use of dental amalgam in the Philippines, adding that alternatives were “two times more expensive.”
Of course, as we’ve seen, that’s only true if you ignore the steep social, environmental and health costs involved in using this demonstrably harmful material. Once you do, composite is considerably cheaper – and, according to research published in Dental Materials, quite possibly longer lasting.
Other recent research has offered findings similar to those of the Philippine paper. A study of Pakistani dental schools, for instance, found that “indoor air at some dental teaching hospitals has 8 -20 times higher level of mercury pollutants than the permissible limit for human health.” A Canadian study published last year in the Journal of Occupational Medicine and Toxicology reported that when amalgams are removed without benefit of suction or water – as the dental schools typically teach – mercury vapor levels exceeded the absolute ceiling of 125.0 μg /m3 36% of the time. (By way of comparison, the Alberta Occupational Health and Safety threshold limit value for mercury vapor over an 8 hour time-weighted period is 25.0 μg/m3.)
This is why it is so absolutely crucial to practice mercury-safe dentistry: to limit these kinds of exposures as much as possible, for the sake of the patients, dental workers and the environment.
These are measures, too, that will need to be followed diligently long after any ban goes through in the Philippines or elsewhere. For even if no new mercury fillings are placed, there are untold billions still in the mouths of people everywhere. Whenever any of those fillings are removed, they must be removed following strict safety protocols. If they aren’t removed in a person’s lifetime, then measures must be taken after death to ensure that, in the case of cremation, the mercury from them doesn’t pollute the environment. (According to Schmalz’s and Arenholt’s textbook on biocompatibility, the limited evidence suggests that any mercury contamination of soil or water from buried bodies is minimal.)