Dental Health Workers' Exposure to Mercury
Are You Exposed to Mercury Vapours in your Dental Office?
Although some dentists refuse to use it, and some countries (for example Norway and Denmark) have banned it, mercury amalgam is still in widespread use in dentistry. Mercury amalgam is a mixture of mercury (a metal which is liquid at room temperature and slowly forms a vapour in air), silver, copper, tin and a small amount of zinc. It has been around since the 1830s and is used for filling cavities in the teeth.
Dentists who use mercury amalgam fillings may be exposing themselves and their team to elevated levels of airborne mercury in their surgeries. Dentists and dental nurses are exposed to mercury vapour when they place or remove fillings and also from the exhaust air from dental vacuum systems.
We know that mercury is absorbed into the body predominantly by inhalation. Mercury is liquid at room temperature and has a high vapour pressure, meaning that even a minor spill could lead to a significant exposure to mercury. Researchers at the University of Birmingham carried out a survey for the Health and Safety Executive of the scientific evidence on the health effects of occupational exposure to mercury, including in dentists' surgeries. The researchers found evidence of central nervous system symptoms and kidney damage among dentists with higher levels of mercury in their bodies. A further report referred to higher levels of brain tumours in dental workers.
Levels of mercury in urine are generally accepted as reflecting levels of exposure to mercury through inhalation of mercury vapour. In a person who has not been exposed in this way, urine mercury levels would be less than five micrograms per litre. A study of dentists in the United States showed that the average urine mercury level was on the high side of this limit, at 5.2 micrograms per litre, with 10 per cent of the study population having levels greater than 10.4 micrograms per litre while in one per cent of the sample it was greater than 33.4 micrograms per litre.
There has been some more recent evidence of ill effects associated with mercury amalgam. Researchers at the University of Bergen, Norway, looked at a group of dental assistants and compared their neurological health with that of a group of assistant nurses who did not work in dentistry. Symptoms were higher among the dental nurse group and included problems with memory and concentration. The problem, if it is caused by mercury, would have related to historic exposure - use of amalgam was common before 1980 but had declined to 5 per cent of all fillings by 2005. Its use is now banned in Norway. Mercury amalgam is, however, still in use in other countries, including the United Kingdom, where around eight million mercury amalgam fillings are done each year.
Therefore dentists and their staff are still being exposed to mercury. One day mercury amalgam may be fully replaced by alternative materials for filling dental cavities. The good news is that dental health is improving and there is less demand for fillings. But, in the meantime, dentists need to be sure that they keep levels of mercury in their surgeries below the Health and Safety Executive maximum limit of 0.05 milligrams/cubic metre. An air purifier - such as the IQAir Dental Hg and FlexVac - can help dentists achieve the required level of air quality by removing mercury vapour and other forms of pollution.
To discover more, contact an expert: 020 3176 0524.