Facts About Mercury

Mercury – where can I get some?

Just what is mercury?

Here are some facts about mercury that should help you. Mercury is one of the poisonous elements that most people could name. It is a silvery liquid at room temperature.

When mercury bonds chemically with other metals, the result is called an “amalgam”. Amalgams have been used in dentistry and mining.

Compounds of mercury with other chemicals also have many uses – in medicine, in agriculture, and in various industries.

How would you be exposed to mercury?

You might be exposed to elemental mercury, to mercury in medical applications, and under other conditions. The facts about mercury in these forms should help you understand how you can be exposed to mercury.

Mercury: the element

As an element – in its pure form – mercury was used in thermometers and thermostats.

Mercury is also used, as a gas at low pressure, in mercury vapour lamps as well as some neon or fluorescent lamps, including compact fluorescent bulbs.

All those products are sealed, and there is no exposure unless the product is broken.

Medical uses of mercury compounds

Mercury compounds have been used in medicine. As a recent example, in 2009-2010, the campaign to counteract the H1N1 influenza pandemic involved vaccination. Some vaccines, those using inactivated viruses, were treated with thimerosal (aka thiomersal; trade name Merthiolate) as a preservative. There is a spirited debate concerning the safety of such vaccines. (Vaccines in multi-dose batches need a preservative to prevent bacterial growth).

Thimerosal may also be used in some other medical products; it is an antiseptic and antifungal agent. You might have had Mercurochrome or Merbromin in your medicine chest – it is a topical antiseptic, but has been banned in the United States. It may still be available in some countries.

Mercury-silver amalgams are used in dental fillings. As the amount of mercury molecules builds up in the human body, that tiny amount of mercury can have a huge impact on the health of the individual. And although a filling may leach mercury into the one patient, the environmental consideration is that waste mercury may be released from the dental laboratories into either landfills or water systems.

Years ago, mercury compounds were used in western societies to treat syphilis, constipation, depression, worms, and other ailments. The ore, cinnabar, had been used in Chinese, Indian and Tibetan medicine.

Other uses of mercury compounds – facts about mercury, past and present

And here are a few more interesting facts about mercury that you might not know.

• Do you remember the Hatter in “Alice in Wonderland”? Craftspeople used mercury compounds to work with animal pelts to make hats. Many were poisoned by fumes or through contact with the mercuric nitrate.
• Mercury compounds are used as fungicides. Seeds may be treated with a mercury compound.
• Some ships and buildings used a mercury-based paint to prevent fungus.
• Thimerosal (aka thiomersal; trade name Merthiolate) has been used in mascara. As with vaccines, the thimerosal is a preservative. Minnesota banned the use of mercury in cosmetics in 2008.
• Thimerosal may also be used in tattoo inks.
• Mercury can react with sodium to form an amalgam. This reaction was used to separate sodium from salt water, to result in sodium hydroxide – better known as caustic soda.
• Although the mercury should be re-used in the factory, some can find its way out, either as waste or in the caustic soda. Mercuric chloride is highly poisonous, but it had been used as a catalyst in making vinyl chloride. Vinyl chloride is then turned into the widely-used plastic polyvinyl chloride, or PVC. (Mercuric chloride is no longer used in making PVC).
• In the past, mining for gold and silver exploited the ability of mercury to form amalgams with those metals. Again, this practice has been reduced due to the obvious environmental concerns. However, smaller mining operations might be continuing to use mercury.
• Mercury may also be released by burning coal. (Mercury forms compounds with sulphur; coal often has sulphur. So, some coal may be contaminated with mercury-sulphur compounds).
• Small, efficient batteries have used mercury to power hearing aids, cardiac pacemakers, watches and small calculators. These batteries provide a steady supply of power until they are nearly exhausted. These batteries are now banned in many countries, including the USA. Most battery packages have warnings against burning the batteries or disposing of them in landfill sites – because that is how the mercury would be released into the environment.
• People who eat a great deal of fish from waters that are contaminated by mercury compounds develop Minamata disease.