Mercury — fears and facts

Philip J. Goscienski, M.D.

March 2013

The squabbling over the harmful effects of mercury in dental filling material known as amalgam began about 150 years ago and it's still going on. In spite of numerous studies in the past couple of decades that have absolved dental amalgam of causing damage to the nervous system or the kidneys, there is still occasional dissent. This will eventually become a moot issue as newer materials for plugging cavities come into wide use.

Childhood vaccines that contain mercury in the form of thimerosal (ethylmercury) were blamed in the past for the alarming rise in the incidence of childhood autism. Although the MMR (measles-mumps-rubella) vaccine was blamed for the autism problem it is ironic that this vaccine never did contain thimerosal. Parental concern resulted in a drop-off of vaccination rates that led to an increase in these and other childhood diseases that persists until the present.

In contrast with ethylmercury, methylmercury is highly toxic. When a factory on the shores of Minimata Bay in Japan discharged mercury-laden wastes into the water in the 1950s, thousands of persons suffered severe damage to the brain and nervous system because they ate fish from those waters.

Certain species of fish such as tuna, swordfish and shark contain relatively high levels of mercury because they are high on the food chain. The benefits of eating fish outweigh the risk of mercury but women who are pregnant and small children should limit their intake of larger fish because of the possible risk to the developing brain of the fetus and child. Smaller fish such as salmon and sardines are excellent substitutes and pose no risk whatsoever from mercury.

The main cause of environmental mercury pollution is the fossil fuel energy industry. In an effort to mitigate global warming many countries, including the United States, have banned the manufacture of incandescent light bulbs, replacing them with compact fluorescent lights (CFL). Although CFLs use much less energy and last many times longer than incandescent bulbs the light that they provide is less. Some consumers complain of the eye-straining low light output. Although CFLs contain small amounts of mercury, breakage produces enough of a health hazard so that government agencies recommend careful handling of the broken bulbs. That includes an admonition not to vacuum the residue and to double-bag the glass fragments, using protective gloves to do so.

Mercury — and its problems — won't go away soon.

Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at