Methylmercury in Ringed Seal Liver – Inuit Health Survey Fact Sheet Series Methylmercury in Ringed Seal Liver

Mercury is a naturally occurring metal. There are several different forms that are present in the environment and some forms pose more risk than others. It can also be produced through industrial activity occurring in regions outside of the Arctic, reaching the Arctic through transport by winds, ocean currents, and rivers, in a process called Long Range Transport. A form of mercury that is of particular concern to human health and is present in the Arctic environment is methylmercury. Did you know?

Microorganisms (organisms that are too small to be seen with the naked eye and are eaten by larger animals) transform mercury present in the environment into the more harmful methylmercury. Long living and predatory animals tend to have higher levels of methylmercury. The organs of an animal used to filter waste tend to have higher levels of methylmercury than other body parts.

Methylmercury is a concern in Nunavut as it can affect the brain development of children and the unborn baby. When pregnant women are exposed to methylmercury, harmful quantities can be transferred from the mother’s blood into unborn babies (who are especially vulnerable to methylmercury’s harmful effects). The health effects of methylmercury can include brain damage evidenced by lower IQ and delay in development. Therefore, women who are pregnant, plan to get pregnant, or might become pregnant are considered to be at greater risk to methylmercury.

Ringed seal liver can contain high levels of methylmercury (10 times higher than ringed seal meat). This makes it a major source of methylmercury in the Inuit diet. Thus, all Inuit women in Nunavut who are pregnant, plan to get pregnant, or might become pregnant, should avoid eating ringed seal liver to prevent mercury’s health effects on their babies.

The meat of the ringed seal is an equally healthy substitute and should be eaten for its cultural and nutritional value.

For Inuit in Nunavut who are not considered to be at greater risk, their bodies can tolerate higher levels (five times) of methylmercury exposure, and can therefore eat ringed seal liver occasionally.

 Ringed seal is very healthy and, like other country food, should be enjoyed when it is available.  Methylmercury can affect babies’ brain development. It is only the liver of ringed seal that is a concern.  All Inuit women in Nunavut who may become pregnant, are planning to get pregnant, or are pregnant should avoid eating ringed seal liver to prevent methylmercury’s health effects on their babies’ brain development.  These women can continue to enjoy ringed seal meat.