Current world use of mercury is estimated to be 10,000 to 15,000 tons annually, of which the United States accounts for about 18 percent.
Fungicides in agriculture, slime control agents in the pulp and paper industry, plastics and electrical apparatus productions, mining and smelting operations are some of mercury's uses. Due to its stability, mercury levels can remain elevated for as long as 100 years after the source of pollution has been discontinued.
Mercury has no known biological function and its presence in living organisms is undesirable and potentially hazardous.
Methylmercury can be bio-concentrated in organisms and bio-magnified through food chains, thus delivering mercury to man and other upper level consumers in concentrated form.
In May of 1996, Cynthia Ann Evans was graduated from the University of Northern Colorado with a BA degree in chemistry. During her studies she had conducted mercury-contamination research for two years. Cindy's interest in the environment had led her to study why rainbow trout reproduced poorly in the Carson River of her home state of Nevada. Over 7,000 tons of mercury was dumped by gold mining operations into the Carson River in the late 1800s, and Cindy's research focused on the toxicological effects of mercury on fresh water trout embryo and a possible solution to the problem.
When Cindy went on to complete her masters degree in biochemistry, her faculty advisor at UNC encouraged her to continue her research and use the findings to publish her thesis. Cindy decided for her research to collect sand from the Carson River and to construct an apparatus in which trout embryos were allowed to develop in conditions similar to the mercury contaminated river. Since this was a first-time project, Cindy had to design the apparatus herself. Cindy's ingenuity led to a patent-pending for the unique design of the apparatus, but this was not to be the end of her talents or curiosity.
On a weekend visit home from college, her mother gave her a bottle of Montana YewTip™ tincture (Taxus brevifolia) for the cold and flu symptoms she was experiencing at the time and Cindy took the tincture back to school. Cindy was pleased with the results of the tincture and one day in the laboratory, on a whim, she put some of it into a container with a batch of trout eggs. To her amazement, she observed the trout eggs absorbing the Yew tincture. The wall of a trout egg will ordinarily repel damaging molecules, but mercury's unique molecular structure will penetrate the egg, causing most of them to die or to mutate the few that hatched. Cindy then observed a substantial increase in the eggs that hatched and survived after having been treated with the Yew tincture. She repeated the test to confirm her observations, achieving even better results. Montana YewTip™ tincture was then included in her study in an effort to reduce the toxic effect of mercury on the fish embryos.
Immediately following fertilization and prior to placement of eggs into the tank, the embryos were placed in a 100 ml beaker and 0.5 ml of tincture was added. Embryos were gently swirled for one minute, solution was removed and embryos were then placed into the aquarium. Each aquarium contained 3 liters of water and 0.5 ml of Yew tincture was added to specified tanks. The first experiment conducted with the tincture involved treated embryos that were used in the control tank (no mercury). All Yew-treated tanks had a 99% survival and up after fourteen days of development. Control tanks with no tincture had an 88% and 70% survival percentage with eggs supplied by two different hatcheries.
The experiments conducted in the presence of various amounts of mercuric nitrate, metallic mercury, and mercury-contaminated soil showed embryo survival was severely compromised. Embryos exposed to mercury without Yew tincture were found not only to have a high mortality, but also, fish that survived suffered from a large number of deformities. The survival percentage for embryos exposed to 200 grams of mercury- contaminated soil was 18%, however, the survival of embryos treated with the Yew tincture and exposed to the same amount of toxic soil increased to 94%, a 76% difference. Embryos that were exposed to 6 milligrams per liter of metallic mercury dissolved in water yielded a survival percentage of 42%, while those treated with the Yew tincture had a 64% survival rate, a 22% difference.
It has been theorized that the Yew tincture possibly contains a metal-binding site within its compounds that protects the embryos from mercury's harmful effects. Further studies could be performed to determine exactly how the Yew tincture protects the embryos from mercury, and whether its use as a protective agent would be feasible for hatcheries.
Toxic metals detoxification in humans is also a possibility and initial results with a few folks using Yew tincture for that purpose have been encouraging.
Cindy's thesis, "The Toxic Effects of Elemental Mercury and Mercury Salts On Embryogenesis of Freshwater Trout" was published in May 2001 by the University of Northern Colorado, College of Art and Sciences, Department of Chemistry and Biochemistry. She earned her masters degree in 2001 and now works as a quality control specialist for the pharmaceuticals industry in California.