 Throughout history, metal has provided many uses and many dangers
Uses
Mercury is valued for its ability to conduct heat, stay liquid at room temperatures and form alloys with other metals such as gold, silver and zinc. It is used to make thermometers, barometers and other scientific instruments. Its ability to form alloys with other metals has led to its use in dental fillings as well as in industrial mining, where it is used to remove metals such as gold from the surrounding rock.Mercury is found naturally, bound up in rocks and soil, but can be released into the air when heated, such as when coal is burned to create electricity.
Mercury is mined from ores or is a by-product of other mining, such as for gold and silver, according to the U.S. Environmental Protection Agency. The last mercury ore mine in the U.S. closed in Nevada in 1990, but secondary (recovered) mercury production still occurs, primarily in Illinois and New York.
History
Mercury was known to the ancient Chinese and Hindus and has been found in 3,500-year-old Egyptian tombs, according to information from the U.S. Department of Energy's Jefferson Lab.
Mercury poisoning was inspiration for the strange symptoms exhibited by Mad Hatter, one of the characters in Lewis Carroll's children's book "Alice in Wonderland."
Milliners were exposed to mercury fumes when stiffening materials used in hat making. Hat makers often suffered from uncontrollable muscle twitches and shakes, distorted vision and confusing speech. In severe cases, the hatters suffered from hallucinations, giving rise to the phrase "mad as a hatter."
The federal government barred the use of mercury by hat manufacturers in 1941.
Mercury was used during the Victorian era in medical cures for certain illnesses, including typhoid. But the treatment often resulted in the patient's death from the purported cure. Mercury was among the pollutants listed in the federal Clean Air Act in 1970. It has only been in the past decade that mercury has come to the forefront as an environmental pollutant, as scientists have begun to seriously consider the long-term effects of certain pollutants and their presence in the environment.
Health
Exposure to spilled mercury can cause health problems, the Environmental Protection Agency says. But a greater EPS concern is the spreading of mercury by industrial emissions. When it rains, mercury can settle into lakes, oceans and other waterways and enter the food chain through fish.
Exposure to elemental mercury, such as mercury in thermometers, is toxic and can cause brain and kidney damage. Elemental mercury can also be absorbed through the skin and cause allergic reactions. Mercury can chemically change into methylmercury, which can build up in fish tissue, a hazard to humans who eat fish or shellfish.
Mercury can have effects on developing fetuses: 8 percent of women of childbearing age have amounts of mercury in their blood that exceeds safe levels, according to the EPA.
Children of women exposed to high level of methylmercury during pregnancy have exhibited abnormalities, including delayed onset of walking and talking and low neurological test scores.
Household sources
One of the most common non-industrial sources of mercury is fluorescent lighting.
When the bulbs are spent, they should be disposed of at a hazardous waste facility. In Whatcom County alone, there are an estimated 281,000 fluorescent lights thrown out each year, a majority mistakenly going into landfills, according to the State Department of Ecology.
Mercury is also found in certain electrical switches used on machinery, including vehicles, thermometers and thermostats.
Last year, the state Legislature passed a law banning the sale of mercury thermometers in the state beginning in January 2006. Some pharmacies have already stopped offering mercury thermometers for sale.
Thousands of mercury thermometers are still in medicine chest throughout the state. The Department of Ecology recommends replacing the thermometers with digital versions.
Dispose of household mercury products at the Whatcom County Disposal of Toxics Facility, 3505 Airport Drive. Hours are 9 a.m. to 4 p.m. Monday through Friday and the first Saturday of each month.
For more information call the county's recycling hotline at 676-5723.
Fish consumption advisories
The Whatcom County Health and Human Service Department warned people about mercury in smallmouth bass and yellow perch from Lake Whatcom in 2001.
The department advises women of childbearing age and children under six years old not to eat the bass and to limit consumption of yellow perch to one meal a week.
Last year, the state Department of Health issued a statewide alert on mercury in freshwater bass, stating that more than half of the bass sampled from 18 lakes in the state had high levels of mercury. Women of childbearing age and children under six are now warned to eat no more than two meals of freshwater bass from Washington waters each month.
In March, the Food and Drug Administration issued a warning to women and young children recommending they should avoid eating shark, swordfish, king mackerel and tilefiel because of high mercury concentrations.
For further information on the national recommendations call the FDA at 1-888-SAFEFOOD.
Dental amalgams
The state Department of Ecology is working with the state's 2,600 dentists to reduce the amount of mercury entering the sewage stream from dental amalgams - the silver-colored cavity filler.
Mercury is added to silver, copper and tin to bind the metals together to make amalgams.
Most dentists have filters in their offices to trap metal particles in the drain. But small particles, including mercury, can still be suctioned into the wastewater pipes and find their way into city sewage treatment plants. When sewage sludge is incinerated, as it is in Bellingham, the mercury can be released into the air.
Studies in Seattle and San Francisco show that up to six percent and 14 percent of the mercury entering wastewater treatment plants comes from dental amalgams, according to the dental association.
There have been no studies that demonstrate mercury in dental amalgams pose any health risk in the mouth, according to a 1997 statement by the World Health Organization.
Local mercury sources diminishing
Georgia-Pacific West Inc. was, for a while, the state's largest emitter of mercury, according to EPA records. The company used mercury for the production of chlorine at a chlor-alkali plant on Bellingham's waterfront.
G-P's mercury emissions stopped soon after the chlorine plant shut down in 1999. During the late 1990s, the plant put out more than 1,000 pounds of mercury in air and water emissions each year, according to the EPA's Toxic Release Inventory.
The BP Cherry Point and ConocoPhillips Ferndale oil refineries also both release mercury. In 2002, BP released four pounds and ConocoPhillips one pound. Small amounts of mercury are released from crude oil when heated during the fuel-refining process.
Last year, the City of Bellingham's sewage sludge incinerator, at Post Point, released four pounds of mercury from the smoke stack at the facility, according to city records.
In the past, waste incinerated at Recomp of Washington and Olivine, both north of Bellingham, were also significant sources of mercury. Olivine stopped incineration in the early 1990s and Recomp stopped incinerating in 1998, according to the Whatcom County Health Department.
Comparison: Whatcom County, state and nation
Large industrial sources in Whatcom County released about five pounds of mercury, most through the air, according to 2002 figures from the EPA.
But EPA figures do not account for some non-industrial sources of air emissions, including four pounds released by the City of Bellingham's incinerator.
County mercury releases reported to the EPA in 2002 are less than one percent of the 751 pounds of mercury released statewide.
Nationwide, there was more than 5 million pounds of mercury released into the air, water and onto land from large industrial facilities. About 40 percent of those emissions are from coal-burning power plants, according to the EPA.
While coal-fired plants are a main source of energy in the Northeast United States, there is only one coal-fired plant in Washington, the Centralia Power Plant, operated by Transalta.
The plant was the state's largest source of mercury air emissions in 2002, with 427 pounds of mercury released, most from air stacks, the latest numbers available from the EPA's Toxic Release Inventory.
The figures reported by industry to the EPA have recently come under scrutiny by environmental groups who charge that many of the pollution figures are severely underreported. Most facilities use government approved formulas to determine how much pollution is leaving their facility, rather than actual tests on smokestacks.
National effort about coal-fired power plants
This year, President George Bush introduced a proposal to reduce mercury emissions from coal-burning power plants by 70 percent by 2018.
Environmentalists have slammed the proposal, stating that it falls far short of requirements for mercury emissions under the Federal Clean Air Act. Former President Bill Clinton had previously proposed a plan to cut mercury emissions by 90 percent by 2008.
Worldwide movement of mercury
Mercury in rainfall is four or more time greater in areas where coal fired power plants exist than in the Seattle or Vancouver, B.C., where there are monitoring stations, according to figures from the National Atmospheric Deposition Program. There are no monitoring stations in Bellingham.
But with large amounts of mercury being emitted from coal-fired power plants in China and other locations outside the United States, some scientists have speculated that mercury may be traveling with weather systems across the globe. In other words, the mercury sent up a smoke stack in Beijing could land in the Pacific Northwest.
Scientists are still arguing about the issue, said David Gay, an atmospheric scientist who monitors mercury in rainfall across the United States.
"It's probably all of the above," Gay said. "Some mercury may be deposited regionally and other mercury may travel globally."
Gay said researchers have not been able to identify a trend of whether the amounts of mercury being deposited in rainfall is rising or declining.
"We're just getting to the point where we've been keeping records long enough to make the decisions about a trend," Gay said.
by Ericka Pizzillo
Newspaper: The Bellingham Herald
Copyright: The Bellingham Herald - Whatcom County, WA
Published: 18 July 2004
Url: news.bellinghamherald.com/stories/20040718/TopStories/198980.shtml |
