Mercury is one of the most hazardous environmental toxins and constitutes a threat to both the environment and human health.
Mercury is a volatile metal that can be airborne over long distances. Mercury cannot be degraded but accumulates in soil, water and living organisms. It is therefore essential that the use and emission of mercury is reduced.
Rules for mercury
There is a general ban on the release of mercury and mercury-containing products in the Swedish market since 2009. The ban aims to minimize emissions to the environment.
Within the EU, mercury is regulated in a new mercury regulation that came into force in 2018. The regulation implements the Minamata Convention on mercury and regulates the use of mercury in a number of different areas.
In several other countries in the world, mercury is still used in some contexts. Because mercury can be transported long distances in the air, mercury contamination is still a problem, both in Sweden and globally.
The spread of mercury
Although mercury has been banned in Sweden since 2009, there is still mercury in the Swedish environment that comes from old emissions. It is mercury that is stored in soil and plants that can be released and spread over lakes and watercourses over time. Mercury is also still spread directly to land and water, for example through emissions from certain industries, leaching from landfills and through the spread of sewage sludge.
Most of the mercury that falls on Swedish soil today comes from other countries. This is because mercury spreads so easily through the air. Even regions that do not emit any mercury themselves are adversely affected by the fact that mercury is transported long distances in the air, for example the Arctic. In order to reduce the pollution of the Swedish environment, we must therefore work to ensure that measures are taken at all levels – locally in Sweden, within the EU and globally.
A major source of airborne mercury emissions at a global level is the burning of coal. Other sources of emissions include smelters, crematoria, small-scale gold extraction and the burning of waste. The spread of mercury from crematoria and dental clinics will cease in time, given the decline in the use of amalgam. It will further decrease due to the requirements in the EU mercury regulation.
In nature, mercury can be converted into the highly toxic form of methylmercury. Methylmercury can damage the central nervous system. During its development the nervous system is at its most vulnerable. Therefore, foetuses and infants in particular need protection. Methylmercury passes through the placenta to the foetus and can affect foetal development. In cases of long-term exposure to low concentrations of mercury, children can show signs of learning difficulties and impaired intellectual capacity.
In cases of high exposure to methylmercury, adults run the risk of cardiovascular disease. These effects are not found, however, in cases of low exposure.
Inorganic mercury mainly affects the kidneys but there are studies that indicate that inorganic mercury can cause similar damage to the central nervous system such as methyl mercury.
How do we ingest mercury?
We can ingest mercury via the food, especially by eating freshwater fish or certain large predatory fish. The mercury we ingest via fish is mainly in the form of methyl mercury. High concentrations in fish is a well-known environmental problem, and the population groups who eat large amounts of fish and shellfish or marine mammals are especially vulnerable.
Another common way to be exposed to mercury is by staying regularly in certain industrial environments and from dental fillings made with amalgam.
About mercury – information at other authorities
There are several Swedish government authorities that are responsible in their respective fields for issues relating to mercury.