Dentists may be flushing mercury down drains

Scores of dentists are feared to be releasing mercury into public sewerage systems because they don’t have equipment to filter the toxic chemical used in fillings.

One in six dentists who applied for public contracts in the past three years failed inspection as they had not installed amalgam separators to remove the mercury from used and excess dental amalgam — the material regularly used to fill cavities.

Documents released under the Freedom of Information Act show health officials are worried the true proportion could be higher as those putting themselves forward for inspection to obtain public contracts would be expected to have higher standards.

Inspections have been carried out at 194 premises from July 2013 to date — 34 failed because they were not using amalgam separators. With around 1,500 dental practices across the country, the number not properly disposing of mercury could be much higher.

Guidelines drawn up by the Department of the Environment intended to instruct dentists to install separators have been in draft form for four years without being finalised.

A proposal by the Dental Inspectorate that its inspectors be given legal powers to make unannounced inspections of dental premises has not been acted upon.

The chief dental inspector, Joseph Mullen, highlighted his concerns about the inspection failure rate in 2013 and twice in 2014, writing to the Department of Environment in March 2014: “This is of concern as these were self-selecting practices who were prepared to undergo scrutiny in order to gain a HSE contract. It is likely that such practices might be at the higher end of the standards spectrum.”

Mr Mullen wrote again 16 months ago, pointing out the continuing high failure rate and the fact those applying for public contracts were warned of the need to dispose of amalgam properly.

In 2013 Ireland signed up to the international Minamata Convention aimed at cutting mercury use and emissions from all sources. It has not yet been formally ratified here.

The use of dental amalgam containing mercury has long been questioned and some Irish dentists now offer only mercury-free alternatives. The position of the Irish Dental Association is that it poses no risk to health.

However, it is accepted that mercury entering water systems or the food chain is a potential hazard.

The Department of the Environment said the European Commission was working on a convention ‘ratification package’ to assist member states.

The HSE said dental schools are prioritising the training of dentists in the use of mercury-free materials. It added: “A sizeable number of dentists now use mercury-free filling materials routinely and are phasing out the use of dental amalgam.”