Dentists, students exposed to high levels of mercury vapors, says study

Dentists, students and patients are being exposed to high levels of hazardous mercury vapors in dental schools and supply stores around the country, according to an environmentalist watchdog.

BAN Toxics (BT) on Thursday released the findings of its study titled “What Is in the Air: Mercury Vapor Levels in Dental Institutions,” which discovered high levels of mercury vapor in the five dental institutions and three supply stores it examined, the names of which the group did not disclose.

In a news release, BT said its study found that mercury vapor in dental institutions exceeded standard reference levels set by the United States Environmental Protection Agency (US EPA), “endangering the health and well-being of dental students, dental workers and patients, among others.”

The study was conducted in partnership with the International Association of Oral and Medical Toxicologists-Philippines, World Alliance for Mercury-Free Dentistry and Asia Center for Environmental Health.

Dental schools

The lead researcher, Myline Macabuhay, said it covered five dental schools, including three in Metro Manila and one each in the Cordillera Administrative Region, Region 7 and 11, and three dental supply stores in Metro Manila.

She declined to name the participants in the study because of nondisclosure agreements, but added that she believed the findings were representative of most dental institutions in the country.

Macabuhay noted that the use of dental amalgam, also known as silver fillings, was still prevalent, especially in dental schools, where it is a requirement in dentistry license exams.

Dental amalgam is used as restorative material in the treatment of tooth cavities. It is an alloy of mercury (50 percent), silver (22-32 percent), tin (14 percent), copper (8 percent) and other trace materials.

Toxic mercury

“Due to its mercury component, pediatricians and toxicologists acknowledge that it is a potent toxic substance that causes adverse effects on neurologic, gastrointestinal and renal organ systems of patients,” according to BT.

“The exposure to toxic mercury vapors in dental institutions is unnecessary and preventable. Learning methodologies can be put into place to avoid toxic mercury.

“This should itself be a strong incentive as well to abandon dental amalgam use in its entirety in the Philippines,” said Richard Gutierrez, BT executive director.

The study measured mercury vapor concentrations from identified sources such as equipment or facilities used in amalgam procedures, storage and immediate disposal sites, among others, using a Lumex RA-915+ Mercury Vapor Analyzer.

It was found that mercury concentration values varied from 967 nanograms per cubic meter (ng/m3) to a high of 35,617 ng/m3—the majority of which were at levels beyond recommended standards, such as the Agency for Toxic Substances and Disease Registry (ATSDR) action level of 1,000 ng/m3.

Evacuation alert level

Some areas posted a concentration of greater than 10,000 ng/m3, which is considered as the “evacuation alert level” by the US EPA, the group said.

The International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) recently confirmed that mercury is a human carcinogen.

“The Department of Health’s phase-out of dental amalgam is much welcome,” said Dr. Lillian Lasaten-Ebuen, president of IAOMT-Philippines.

“Mercury-free alternatives are now widely-available, which are safer and as cost effective as amalgam. Philippine dentistry should move beyond amalgam and we should prepare the future generation of dentists to embrace better and safer alternatives for their patients,” she said.

BT called for a change in the dental curriculum in schools to exclude the use of dental amalgams in line with the move to phase out mercury use in the health sector by 2016.

“Most importantly, this study puts gravity to the need to phase-out mercury use in all sectors, especially in the field of health,” Gutierrez added.

“We go to our doctors and dentists in order to be well, and mercury has no place in a healthy society. We need to uphold our Hippocratic oath as health practitioners, to help the sick and abstain from harming any person,” Ebuen said.

The study was supported by the World Alliance for Mercury-Free Dentistry and the Swedish Society for Nature Conservation.