Mercury
Your Health and the Environment

Exposure from Dental Amalgam and Thimerosal Vaccines

Q28. Should I avoid mercury amalgam dental fillings?
Current evidence does not indicate that dental amalgam is causing illness in the general population. However, it is generally a good idea to reduce exposure to mercury if this can be achieved at a reasonable cost and without other adverse effects. Health Canada recommends non-mercury filling materials be considered for restoring the primary teeth of children where the mechanical properties of the material are suitable. Pregnant women and people who may have allergic hypersensitivity to mercury or who have impaired kidney function should avoid the use of dental fillings containing mercury amalgam.

Q29. Should I have my existing mercury amalgam dental fillings replaced?
Health Canada does not support removal of sound amalgam fillings in patients who have no indication of related adverse health effects. Individuals who have developed hypersensitivity to amalgam should replace existing mercury amalgam fillings with another material if their physician recommends this. Amalgam fillings should not be removed while a woman is pregnant because she might be exposed to mercury vapour during removal.

Q30. What is thimerosal and why is it used in vaccines?
Thimerosal is a preservative that contains mercury and it has been used in some vaccines and other products since the 1940's to prevent spoilage and contamination. Efforts are under way to eliminate thimerosal from product formulations, where possible.

Q31. If patients have a choice of vaccines, one with mercury or one without, which should they choose?
They should choose mercury-free vaccines, if they are available and if they are just as suitable as thimerosal vaccines. Patients should discuss this with their doctor and follow his/her advice. The most important consideration is that parents should not miss an opportunity to have their children immunized. Currently, the only thimerosal-containing vaccine in routine use in the infant immunization schedules of some Canadian jurisdictions is the hepatitis B vaccine.
(See
http://www.hc-sc.gc.ca/pphb-dgspsp/publicat/ccdr-rmtc/02vol28/dr2809ea.html
http://www.hc-sc.gc.ca/pphb-dgspsp/publicat/ccdr-rmtc/03vol29/acs-dcc-1/index.html)

Q32. Why is the federal government not recommending removal of thimerosal vaccines from use if there is a concern?
Making vaccines safer and more effective is a constant goal for the federal government and vaccine manufacturers. But decisions must be based on weighing the risks and benefits of each vaccine. In some cases, mercury-free alternatives may not be available or may not be as suitable as the thimerosal formulations. Missing vaccinations would put children at risk from disease. Since thimerosal vaccines contain only minute levels of mercury, the benefits of vaccination with them far outweigh the minimal risks associated with thimerosal.

Q33. What degree of mercury exposure has my six-month-old baby encountered from vaccines? Is there a health risk associated with this level of exposure?
There is little chance for a six month old to be exposed to mercury through vaccination. Most vaccines licensed in Canada do not contain thimerosal. Since 1994, all routine childhood vaccines, with the exception of the flu vaccine, administered in Canada have not contained thimerosal. Thimerosal is not added to single dose vaccines.

In Canada, vaccines to prevent the following diseases are used for routine immunization of children and do not contain thimerosal:

• diphtheria
• tetanus (lockjaw)
• pertussis (whooping cough)
• polio
• rubella (German measles)
• measles (red measles)
• mumps
• hepatitis B (available free to children only in some provinces and territories)
• Haemophilus influenzae type b disease

For immunization of infants against hepatitis B, parents or guardians in some provinces and territories have the choice of a thimerosal-free vaccine.

Q34. Do children receive toxic levels of mercury from vaccines?
No. Children who receive vaccines containing thimerosal may be exposed to minute levels of mercury, but these are very far below any toxic level.