I'm aging myself here.....(remembering glass thermometers) And I know I have seen a few break..but I didn't know that there was enough mercury in a thermometer to pollute a 20 acre lake........we never treated mercury spills seriously enough.....Image the amount of mercury vapors in a hospital. Not to mention the vaccines we have been given......that contain mercury... Maybe nurses and health care professionals have had more exposure to mercury than we know.... The Problem with Mercury In addition to PVC and DEHP, another toxic substance that nurses work with daily is mercury. Mercury is a liquid metal that is widely used in the hospital because it responds easily to temperature and pressure changes. Mercury is found in thermometers, and in some weighted esophageal dilators, feeding tubes, saline with thimerosal, mercurochrome, dental amalgams, batteries, sphygmomanometers, barometers, manometers, fluorescent lamps, switches, thermostats, cleaners, microwave ovens and some plastics. Like PVC, mercury is omnipresent around the hospital. Mercury is a potent neurotoxin, and carcinogenic in large doses. In 1865, Lewis Carroll wrote about a character called the Mad Hatter in Alice's Adventures in Wonderland. The Mad Hatter was fictional, but the strange behavior he displayed was not. In the hatmaking industry in the 1800's, hatters used mercury in the felt-making process. Many hatters subsequently developed mercury poisoning. Even today we use the phrase "mad as a hatter" to denote someone who is a bit crazy. Mercury attacks the central nervous system and can damage the brain, kidneys and lungs. It crosses the blood-brain barrier as well as the placenta. Methylmercury, the most common and most dangerous form of mercury, is classified as a reproductive toxin for its effects on fetal development. During fetal development, exposure to methylmercury prevents the brain and nervous system from developing normally. Nurses are exposed to mercury in two ways. The first and most significant exposure occurs through human consumption of fish. Large amounts of mercury are made airborne upon incineration of mercury-containing products. This happens when mercury is incinerated both in medical waste and municipal waste incinerators. Once mercury is in the atmosphere, its falls to the ground with rain and snow, landing on soil and in water sources. When it falls into water, mercury bioaccumlates in the muscle tissues of fish. When fish is consumed, humans also consume all of the mercury burden accumulated by that particular fish during its lifetime. There is no way to remove mercury from fish by cleaning them, soaking them or otherwise cooking them in a special way. The second way nurses are exposed to mercury is through occupational exposure. When mercury containing equipment breaks, nurses are exposed to the mercury vapors and also may have actual contact with the substance itself during the incident and clean-up. When a spill involves a patient, the nurse may be first on the scene to help cleanup the patient. If exposed, symptoms of mercury poisoning include: impairment of the peripheral vision; disturbances in sensation, usually in the hands, feet and mouth; lack of coordination of movements such as writing; impairment of speech, hearing and walking; muscle weakness; skin rashes; mood swings; memory loss; mental disturbances; coma; and death. Like dioxin, a little mercury goes a long way. Four grams of mercury (the amount found in four glass household thermometers) will contaminate a twenty-acre lake activating fish advisories. For comparison, a teaspoon of mercury contains 70 grams of mercury. Fish in 37 states and in 1,308 water bodies have been contaminated with mercury at levels that make them unsafe for human consumption. Like dioxin, mercury bioaccumulates up the food chain, with larger fish carrying larger concentrations. Humans eating 1-2 ounces of fish with predicted mercury concentrations above one part per million (micrograms) per day would be ingesting mercury at levels approaching or exceeding ten times the US EPA's RfD. (The RfD is a daily ingestion level anticipated to be without adverse effects to persons, including sensitive subpopulations, over a lifetime.) Tuna, the most consumed fish in the US, is at the top of the aquatic food chain containing 0.206 micrograms of mercury per gram of wet weight. In understandable terms, ingesting one tuna sandwich a day, containing 1-2 ounces of tuna, doses the human body with 20 times the RfD. Many of us consume tuna thinking that we are eating healthily when in fact, we are consuming mercury along with the tuna. Fish eating subpopulations, such as Eskimos, are especially vulnerable to mercury poisoning.