Research Finds Mercury from in-ground Wastewater Disposal
As towns across Cape Cod struggle with problems stemming from septic systems, a recent study by a Woods Hole Oceanographic Institution (WHOI) scientist focused on one specific toxic by-product: mercury. In a study of local groundwater, biogeochemist Carl Lamborg found that microbial action on wastewater transforms it into more mobile, more toxic forms of the element.
Arsenic, Mercury, Selenium in Asian Carp Not a Health Concern
Researchers at the Prairie Research Institute’s Illinois Natural History Survey have found that, overall, concentrations of arsenic, selenium and mercury in bighead and silver carp from the lower Illinois River do not appear to be a health concern for a majority of human consumers. The full results of the study have been published in the journal Chemosphere.
Average mercury concentration in fillets was below the US Food and Drug Administration Action Level and EPA Screening Value for Recreational Fishers, though some individual fish had mercury concentrations high enough to recommend limiting consumption by sensitive groups (children < 15 years and women of childbearing age) to one meal/week. Mercury concentrations were greater in bighead carp and were elevated in both species taken from the confluence of the Illinois and Mississippi rivers. “These fish are low in mercury in comparison to many other commercially available fish. However, as always consumers need to make informed decisions about their food choices,” says Jeff Levengood, lead investigator of the study.
Burning Biomass Pellets Can Lower Mercury Emissions
For millions of homes, plants, wood and other types of “biomass” serve as an essential source of fuel, especially in developing countries, but their mercury content has raised flags among environmentalists and researchers. Scientists are reporting that, among dozens of sources of biomass, processed pellets burned under realistic conditions in China emitted relatively low levels of the potentially harmful substance. The report was published in the ACS journal Energy & Fuels.
When gold was discovered in California in 1849, the miners were confronted with a problem: there were huge amounts of the precious metal in the foothills of the Sierra and the only way to get it out was to blast it out of the soil with high-pressure hoses.
The resulting mud containing the gold was run through sluices and mixed with mercury so the gold would settle to the bottom. The remains of the 19th-century practice are still visible in the area, and the poisonous mercury is now slowly making its way toward the fruit and nut orchards, and the rice fields of California’s lush Central Valley, America’s food basket, according to new research by a team of British and American scientists.
Hot spots of mercury pollution in aquatic sediments and soils can contaminate local food webs and threaten ecosystems, but cleaning them up can be expensive and destructive. Researchers from the Smithsonian Environmental Research Center and the Univ. of Maryland, Baltimore County have found a new low-cost, nonhazardous way to reduce the risk of exposure: using charcoal to trap it in the soil.
Mercury-contaminated “Superfund sites” contain some of the highest levels of mercury pollution in the U.S., a legacy of the many industrial uses of liquid mercury. But despite the threat, there are few available technologies to decrease the risk, short of digging up the sediments and burying them in landfills — an expensive process that can cause significant ecological damage.
Univ. of Michigan researchers and their Univ. of Hawaii colleagues say they’ve solved the longstanding mystery of how mercury gets into open-ocean fish, and their findings suggest that levels of the toxin in Pacific Ocean fish will likely rise in coming decades.
Using isotopic measurement techniques developed at U-M, the researchers determined that up to 80 percent of the toxic form of mercury, called methylmercury, found in the tissues of deep-feeding North Pacific Ocean fish is produced deep in the ocean, most likely by bacteria clinging to sinking bits of organic matter.
Researchers See New Challenges for Mercury Cleanup
More forms of mercury can be converted to deadly methylmercury than previously thought, according to a study published in Nature Geoscience. The discovery provides scientists with another piece of the mercury puzzle, bringing them one step closer to understanding the challenges associated with mercury cleanup.
Earlier this year, a multidisciplinary team of researchers at Oak Ridge National Laboratory discovered two key genes that are essential for microbes to convert oxidized mercury to methylmercury, a neurotoxin that can penetrate skin and at high doses affect brain and muscle tissue, causing paralysis and brain damage.
June began with a gorgeous trio of planets: Mercury, Venus and Jupiter, low on the west-northwest horizon. As the month progresses, Jupiter slips into the sunset while Mercury and Venus rise higher in the sky.
Asteroid 1998 QE2, which safely passed by Earth on May 31, is visible in the night skies only through medium sized or larger telescopes.
Every Thursday, Laboratory Equipment features a Scientist of the Week, chosen from the science industry’s latest headlines. This week’s scientist is Laura Sherman from the Univ. of Michigan. She and a team found that a common test overestimates mercury exposure from dental fillings.
Test Overestimates Mercury Exposure from Dental Fillings
A common test used to determine mercury exposure from dental amalgam fillings may significantly overestimate the amount of the toxic metal released from fillings, according to Univ. of Michigan researchers.
Scientists agree that dental amalgam fillings slowly release mercury vapor into the mouth. But both the amount of mercury released and the question of whether this exposure presents a significant health risk remain controversial.
By analyzing Mercury’s rocky surface, scientists have been able to partially reconstruct the planet’s history over billions of years. Now, drawing upon the chemical composition of rock features on the planet’s surface, scientists at MIT have proposed that Mercury may have harbored a large, roiling ocean of magma very early in its history, shortly after its formation about 4.5 billion years ago.
The scientists analyzed data gathered by MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging), a NASA probe that has orbited the planet since March 2011. Later that year, a group of scientists analyzed X-ray fluorescence data from the probe, and identified two distinct compositions of rocks on the planet’s surface. The discovery unearthed a planetary puzzle: what geological processes could have given rise to such distinct surface compositions?
NASA has recently discovered a very strange planet. Its days are twice as long as its years. It has a tail like a comet. It is hot enough to melt lead, yet capped by deposits of ice. And to top it all off… it appears to be pink. The planet is Mercury.
Of course, astronomers have known about Mercury for thousands of years, but since NASA’s MESSENGER probe went into orbit around Mercury in 2011, researchers feel like they’ve been discovering the innermost planet all over again. One finding after another has confirmed the alien character of this speedy little world, which you can see this week with your own eyes.
Chemists at the Univ. of Burgos have manufactured a sheet that changes color in the presence of water contaminated with mercury. The results can be seen with the naked eye but when photographing the membrane with a mobile phone the concentration of this extremely toxic metal can be quantified.
Mercury contamination is a problem that is particularly affecting developing countries. It poses a risk to public health since it accumulates in the brain and the kidneys causing long term neurological illnesses. It is emitted from industrial and mining waste, especially small-scale gold mining.
February is a great month to spot Mercury, the smallest and fastest-moving planet. It reaches its highest point above the sunset horizon on February 16th, when it appears 18 degrees from the sun.
On February 6th through the 10th, catch Mercury and Mars less than 10 degrees above the horizon just after sunset. The moon joins the parade on the 11th as a faint crescent above the two planets. On February 15 a small asteroid named 2012 DA-14 will whiz by, less than 18,000 miles from Earth. It doesn’t pose any threat and it’ll be a challenging object to see at magnitude 8.
A new, and legally binding, international treaty to reduce harmful emissions of mercury was adopted by more than 140 nations, capping four years of difficult negotiations but stopping short of some of the tougher measures that proponents had envisioned. The new accord aims to cut mercury pollution from mining, utility plants and a host of products and industrial processes, by setting enforceable limits and encouraging shifts to alternatives in which mercury is not used, released or emitted.
Mercury, known to be a poison for centuries, is natural element that cannot be created or destroyed. It is released into the air, water and land from small-scale artisanal gold mining, coal-powered plants, and from discarded electronic or consumer products such as electrical switches, thermostats and dental amalgam fillings. Mercury compound goes into batteries, paints and skin-lightening creams.