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(Chem) (Environment) Metals in Biology and Environment

 
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adedios
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PostPosted: Fri Sep 29, 2006 11:07 pm    Post subject: (Chem) (Environment) Metals in Biology and Environment Reply with quote






Manganese can keep toxic hydrogen sulfide zones in check in aquatic systems, researchers report in 'Science'

University of Delaware

1:38 p.m., Sept. 29, 2006--Manganese, in trace amounts, is essential to human health. Now a research team from the University of Delaware, Scripps Institution of Oceanography, the University of Hawaii and Oregon Health and Science University has discovered that a dissolved form of the mineral also is important in waterways such as the Black Sea and Chesapeake Bay, where it can keep toxic hydrogen sulfide zones in check.

The results are reported in the Sept. 29 issue of the prestigious journal Science and also are the focus of the journal’s “Perspectives” column, “Geochemistry: Manganese Redox Chemistry Revisited," written by Kenneth S. Johnson of the Monterey Bay Aquarium Research Institute in Moss Landing, Calif.

For the full article:

http://www.udel.edu/PR/UDaily/.....92906.html

*************************************************************

Questions to explore further this topic:

What are metals?

http://www.paete.org/forums/viewtopic.php?t=1172

Exploring Ancient Mysteries: A Black Sea Journey

http://www.ocean.udel.edu/blac.....index.html

What is the zone of death?

http://www.k12.de.us/talley/turkey/zoneofdeath.htm

What is manganese?

http://en.wikipedia.org/wiki/Manganese
http://www.atsdr.cdc.gov/tfacts151.html

What is hydrogen sulfide?

http://en.wikipedia.org/wiki/Hydrogen_sulfide


How metals can kill or cure

http://www.msnbc.msn.com/id/3077423/

Metals in health and disease

http://www.portfolio.mvm.ed.ac...../index.htm

Environment and Health Effects of the Elements (A Periodic Table)

http://www.lenntech.com/periodic-chart.htm

Metals in Biology (Powerpoint presentations)

http://www.cf.ac.uk/biosi/staf.....index.html

Metals in proteins

http://chem.ps.uci.edu/~pfarmer/127i/index.html

What is inorganic chemistry?

http://en.wikipedia.org/wiki/Inorganic_chemistry
http://www.chemguide.co.uk/inorgmenu.html
http://www.chemistry.org/porta.....inorg.html

A collection of topics and links relevant to inorganic chemistry

http://www.ias.ac.in/initiat/s.....ganic.html

What is bioinorganic chemistry?

http://en.wikipedia.org/wiki/B....._chemistry
http://www.rsc.org/ej/DT/1997/DT973903.PDF

Bioinorganic Chemistry Special Feature


GAMES

http://www.sciencemuseum.org.u...../cards.asp
http://www.copper.org/copperho.....edots.html


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PostPosted: Thu Dec 14, 2006 8:55 am    Post subject: Chelation therapy reduces lead-exposure problems Reply with quote

Dec. 13, 2006
Chelation therapy reduces lead-exposure problems but could create lasting effects for children treated for autism, CU researchers find

By Krishna Ramanujan

Lead chelation therapy -- a chemical treatment to remove lead from the body -- can significantly reduce learning and behavioral problems that result from lead exposure, a Cornell study of young rats finds.

However, in a further finding that has implications for the treatment of autistic children, the researchers say that when rats with no lead in their systems were treated with the lead-removing chemical, they showed declines in their learning and behavior that were similar to the rats that were exposed to lead.



Alexis Wenski-Roberts
Barbara Strupp, associate professor of nutritional sciences and of psychology, at work in the lab.
Chelating drugs, which bind to lead and other metals in the blood, are increasingly being used for the treatment of autism in children.

"Although these drugs are widely used to treat lead-exposed children, there is remarkably little research on whether or not they improve cognitive outcomes, the major area of concern in relation to childhood lead poisoning," said Barbara Strupp, Cornell associate professor of nutritional sciences and of psychology and the senior author of the study, which was published in a recent issue of Environmental Health Perspectives.

Studies on the safety or effectiveness of the drugs for treating autism are similarly lacking, Strupp said.

Strupp added that to her knowledge this is the first report that shows that chelation therapy can reduce behavioral and learning problems due to lead exposure as well as the first to show that this type of treatment can have lasting adverse effects when administered in the absence of elevated levels of heavy metals.

The study used succimer (brand name, Chemet), the most widely prescribed drug for the treatment of lead poisoning. Doctors prefer succimer to other such drugs because it can be given orally on an outpatient basis, and it leaches less zinc, iron and other essential minerals out of the body. Although the Centers for Disease Control recommends chelation therapy only for children whose blood lead levels exceed 45 micrograms per deciliter, such drugs as succimer are commonly administered at much lower levels of exposure, due to concerns about lasting complications with even slightly elevated blood lead levels.

It is important to remove lead from the body as quickly as possible to prevent or lessen lasting damage to the developing brain. High-lead exposure from peeling lead-based paint can lead to coma, convulsions and even death. At lower levels, lead exposure causes attention deficits, delinquency and difficulty regulating emotions and can lower IQ scores at a rate of about one IQ point per microgram/deciliter of exposure.

The study used rats -- whose mental and behavioral responses to lead exposure are similar to humans' -- and exposed them to moderate- and high-lead levels (administered via mothers' milk). A third group -- the control -- was not exposed. Exposures were followed by a treatment with succimer or placebo. Immediately thereafter, the researchers conducted automated tests over six months on the rats' attention, memory and abilities to learn and regulate emotions.

The rats with moderate-lead exposure benefited greatly from the succimer: Their test results were indistinguishable from the control test results. Rats exposed to higher lead levels showed benefits in the emotional domain: After succimer treatment, they behaved similarly to the control group. However, the treatment only slightly improved their learning deficit.

In the group that had no lead exposure but were given succimer, "we found lasting cognition and emotion-regulation [deficits] that were as pervasive and large as rats with high lead exposure," said Strupp. She added that one possibility is that succimer, in the absence of lead, may disrupt the balance of such essential minerals as zinc and iron. "These findings raise concerns about the use of chelating agents in treating autistic children," she said.

The study was funded by the National Institutes of Health.

Among other colleagues, Diane Stangle, a psychology graduate student, and Stephane Beaudin, a research associate in nutritional sciences, contributed to this work.
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PostPosted: Wed Jan 24, 2007 9:41 am    Post subject: Study finds mercury prevalent in many western fish Reply with quote

Oregon State University
23 January 2007

Study finds mercury prevalent in many western fish
CORVALLIS, Ore. – A new survey by researchers at Oregon State University and the U.S. Environmental Protection Agency of more than 600 rivers and streams in the western United States found widespread mercury concentrations in fish.

Though few of the more than 2,700 fish analyzed in the study contained alarmingly high levels of mercury, the prevalence of the element throughout 12 western states caught the researchers somewhat by surprise.

"Mercury is everywhere," said Alan Herlihy, a research associate professor with OSU's Department of Fisheries and Wildlife and one of the authors of the study. "It was literally in every fish we sampled, which suggests an atmospheric source. There also tended to be a noticeable difference between 'piscivores,' or fish-eating fish, and non-piscivores such as salmonids."

The researchers found that mercury levels were much higher in the larger fish-eating species, including bass, walleye, northern pike and pikeminnow. These piscivores are not as widespread throughout western river systems as salmonids, such as rainbow and cutthroat trout, which had lower levels of mercury.

Results of the study were published earlier this month in the journal Environmental Science and Technology.

The researchers say the risk for humans who may occasionally eat fish from the streams is fairly low and they compare the mercury levels in most of the larger piscivorous fish they analyzed to that found in cans of store-bought tuna. Consumption of those products in moderation is considered safe, though infants, young children, pregnant women and persons who eat a lot of fish have higher risk levels than the general population.

Less clear is the impact of that mercury on fish-eating birds and mammals, said Robert Hughes, also an author on the paper and an OSU fisheries and wildlife research associate professor.

"If I were a mink or an otter," Hughes said, "I'd be concerned. Those guys are loading up on fish containing mercury and we don't really know at what levels they may be affected. In birds, the effects of mercury contamination are neurological or behavioral – and often subtle. They may not clean their young, or they may leave eggs unattended in their nests.

"We simply haven't done enough studies to know all of the impacts, especially on fish-eating animals," Hughes added.

The study, based on data collected from EPA's Environmental Monitoring and Assessment Program, encompassed nearly 188,000 miles of perennial streams and rivers in the western United States. The selection of the more than 600 creek and river sample sites was done randomly to address regional questions about the prevalence of mercury contamination among fish in western rivers; not to do a stream-by-stream analysis of the impact.

The EPA's "tissue-based water quality criterion" is set at 0.3 micrograms of mercury per gram of fish tissue. In the survey, only 2.3 percent of the stream network that contained large (5 inches or longer) salmonids had mercury levels at or exceeding that 0.3 mg level. Salmonids were the most prevalent group of species, found in 41 percent of the network sampled.

On the other hand, large bass, walleye and other piscivores were found in only 10 percent of the streams and rivers, yet 57 percent of them met or exceeded the 0.3 microgram level.

"The difference in mercury levels between salmonids and piscivores is likely a function of their diet," Hughes said.

"Most of the salmonids we sampled were insect-eaters. Older, very large salmon may respond more like piscivores, but we didn't sample salmonids of that size."

In looking at mercury levels in fish across the West, the most important factors "were where the fish were in the food web, and their ages," Herlihy said. "The older a fish is, the larger it is, and the more fish that it eats, the more likely it is to bioaccumulate mercury."

Mercury levels of 0.1 micrograms per gram of tissue are considered a threshold of concern for fish-eating mammals, though little research has been done on how different levels of mercury affect mink, otter and related animals. Nevertheless, the survey found that 93 percent of the streams and rivers with large piscivores exceeded that level of mercury deemed "protective" for fish-eating mammals.

Conducting the study with Herlihy and Hughes were Spencer Peterson and John Van Sickle of the EPA National Health and Ecological Effects Research Laboratory, located on the OSU campus.

Mercury entering the water via the atmosphere has a variety of natural and manmade sources, the researchers say, including coal power plants from as far away as China, the burning of heavy oils and other fossil fuels, and even forest fires.

In the survey, the researchers did find 13 fish from eight different sites that had very high mercury concentrations – levels of 1.0 microgram or higher – likely indicating a point source. These high levels could be caused by nearby mines, dump sites or gravel pits, they added.

"There are mercury 'hotspots' out there," Hughes said, "but they are not common in the West. What we found, though, is that mercury is in fish throughout the western United States, and at higher levels in piscivores than in salmonids."


###
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PostPosted: Thu Mar 08, 2007 9:39 am    Post subject: Mercury contamination of fish warrants worldwide public warn Reply with quote

University of Wisconsin-Madison
8 March 2007

Mercury contamination of fish warrants worldwide public warning

MADISON -The health risks posed by mercury contaminated fish is sufficient to warrant issuing a worldwide general warning to the public — especially children and women of childbearing age-to be careful about how much and which fish they eat. That is one of the key findings comprising "The Madison Declaration on Mercury Pollution" published today in a special issue of the international science journal Ambio.

Developed at the Eighth International Conference on Mercury as a Global Pollutant last August in Madison, Wis., the declaration is a synopsis of the latest scientific knowledge about the danger posed by mercury pollution. It presents 33 principal findings from five synthesis papers prepared by the world's leading mercury scientists and published in the same issue of Ambio. The declaration and supporting papers summarize what is currently known about the sources and movement of mercury in the atmosphere, the socioeconomic and health effects of mercury pollution on human populations, and its effects on the world's fisheries and wildlife.

Five other major findings in the declaration were:

On average, three times more mercury is falling from the sky today than before the Industrial Revolution 200 years ago as a result of the increasing use of mercury and industrial emissions.
The uncontrolled use of mercury in small-scale gold mining is contaminating thousands of sites around the world, posing long-term health risks to an estimated 50 million inhabitants of mining regions. These activities alone contribute more than 10 percent of the mercury in Earth's atmosphere attributable to human activities today.
Little is known about the behavior of mercury in marine ecosystems and methylmercury in marine fish, the ingestion of which is the primary way most people at all levels of society worldwide are exposed to this highly toxic form of mercury.
Methylmercury exposure now constitutes a public health problem in most regions of the world.
Methylmercury levels in fish-eating birds and mammals in some parts of the world are reaching toxic levels, which may lead to population declines in these species and possibly in fish populations as well.
"The policy implications of these findings are clear," said James Wiener, a Wisconsin Distinguished Professor at the University of Wisconsin-La Crosse who served as technical chair for last summer's conference. "The declaration and detailed analyses presented in the five supporting papers clearly show that effective national and international policies are needed to combat this global problem." Published by the Royal Swedish Academy of Sciences, Ambio (www.ambio.kva.se) is widely recognized as an important international forum for debate on scientific, social, economic and cultural issues affecting the human environment.

Wiener said the Madison Declaration summarizes a year-long effort by many of the world's leading mercury scientists, assembled into four expert panels, to review and synthesize the major mercury science findings. Every member of all four scientific panels endorsed the declaration, he said. Wiener added that all 1,150 participants at the conference were invited to express their confidence in the experts' findings, and the vast majority of those who did so agreed with the experts' conclusions.

Other major findings in the declaration include:

Increased mercury emissions from developing countries over the last 30 years have offset decreased emissions from developed nations.
There is now solid scientific evidence of methylmercury's toxic health effects, particularly to the human fetus.
New evidence indicates that methylmercury exposure may increase the risk of cardiovascular disease, particularly in adult men.
Increasing mercury concentrations are now being found in a number of fish-eating wildlife species in remote areas of the planet.
The actual socioeconomic costs of mercury pollution are probably much greater than estimated because existing economic analyses don't consider mercury's impacts on ecosystems and wildlife.
The concentration of methylmercury in fish in freshwater and coastal ecosystems can be expected to decline with reduced mercury inputs; however, the rate of decline is expected to vary among water bodies, depending on the characteristics of a particular ecosystem.

###

Besides Wiener, conference organizers included James Hurley of the University of Wisconsin-Madison Sea Grant Institute, David Krabbenhoft of the U.S. Geological Survey and Christopher L. Babiarz of the UW-Madison Water Science & Engineering Laboratory. Wisconsin Sea Grant, USGS and UW-La Crosse were among the major sponsors of the 2006 conference.
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PostPosted: Tue Mar 13, 2007 7:15 am    Post subject: Chromium 6: A Killer Compound With An Improbable Trigger Reply with quote

Chromium 6: A Killer Compound With An Improbable Trigger

Brown University
13 March 2007

Chromium 6, the cancer-causing compound that sparked the legal crusade by Erin Brockovich, can be toxic in tiny doses. Brown University scientists have uncovered the unlikely culprit: vitamin C. In new research, the Brown team shows that when vitamin C reacts with even low doses of chromium 6 inside human cells, it creates high levels of cancer-causing DNA damage and mutations.

PROVIDENCE, R.I. [Brown University] — Even miniscule amounts of chromium 6 can cause cancer. Blame that do-gooder nutrient, vitamin C.

Brown University researchers have discovered that naturally occurring vitamin C reacts inside human lung cells with chromium 6, or hexavalent chromium, and causes massive DNA damage. Low doses of chromium 6, combined with vitamin C, produce up to 15 times as many chromosomal breaks and up to 10 times more mutations – forms of genetic damage that lead to cancer – compared with cells that lacked vitamin C altogether.

This finding is startling, said Anatoly Zhitkovich, an associate professor of medical science at Brown who oversaw the experiments. Outside cells, Zhitkovich said, vitamin C actually protects against the cellular damage caused by hexavalent chromium, the toxic chemical that starred as the villain in the true-to-life Hollywood drama, Erin Brockovich. In fact, vitamin C has been used as an antidote in industrial accidents and other instances when large amounts of chromium are ingested.

Vitamin C works protective wonders because it is a powerful antioxidant, blocking cellular damage from free radicals. Specifically, the vitamin rapidly “reduces,” or adds electrons, to free radicals, converting them into harmless molecules. This electron transfer from vitamin C to chromium 6 produces chromium 3, a form of the compound that is unable to enter cells.

But what happens when chromium and vitamin C come together inside cells? Because vitamin C isn’t found in cells grown in a lab, Zhitkovich and his team conducted experiments using human lung cells supplemented with vitamin C. They learned that when vitamin C is present, chromium reduction has a very different effect. Cellular vitamin C acted as a potent toxic amplifier, sparking significantly more chromosomal breaks and cellular mutations.

“When we increased the concentration of vitamin C inside cells, we saw progressively more mutations and DNA breaks, showing how seemingly innocuous amounts of chromium can become toxic,” Zhitkovich said. “For years, scientists have wondered why exposure to small amounts of hexavalent chromium can cause such high rates of cancer. Now we know. It’s vitamin C.”

Hexavalent chromium is used to plate metals and to make paints, dyes, plastics and inks. As an anticorrosive agent, it is also added to stainless steel, which releases hexavalent chromium during welding. Hexavalent chromium causes lung cancer and is found in 40 percent of Superfund sites nationwide. This is the toxic metal, found in drinking water in a small California town, that Erin Brockovich campaigned against, successfully winning residents a record settlement of $333 million in 1996.

Zhitkovich said his team’s research, published in Nucleic Acids Research, might have policy implications. When combined with vitamin C, chromium 6 caused genetic damage in cells in doses four times lower than current federal standards, Zhitkovich said. If additional research backs these findings, he said federal regulators might want to lower exposure standards.

Zhitkovich is part of a major Brown research initiative, the Superfund Basic Research Program, which addresses the health and environmental concerns created by hazardous waste contamination. As part of this program, funded by the National Institute of Environmental Health Sciences, Zhitkovich is conducting basic research that may result in a medical test that assesses DNA damage from hexavalent chromium.

Former Brown graduate student Mindy Reynolds was lead author of the journal article. Brown research assistant Lauren Stoddard and postdoctoral research associate Ivan Bespalov also took part in the research.

The National Institutes of Health funded the work.
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PostPosted: Sat Mar 31, 2007 7:21 am    Post subject: Monitoring poisons in the environment -- a woolly matter Reply with quote

Society for Experimental Biology
30 March 2007

Monitoring poisons in the environment -- a woolly matter

Heavy metals are present in variable amounts in the natural environment in the UK. Dr Jennifer Sneddon (Liverpool John Moores University) will present the results of a pilot study assessing the use of upland sheep wool as a bio-monitoring device for natural levels of heavy metals in the Lake District and Wales at the Society for Experimental Biology’s Annual Meeting in Glasgow (31st March – 2nd April).

Significant correlations were found between the amount of copper and lead found in washed wool from sheep and in local streams. Median copper concentration in North Ronaldsay wool was comparatively high despite lower soil concentrations. Shetland sheep appeared to accumulate more lead than Swaledale sheep. Another significant observation related to the sex of the sheep – values for wool concentration of both lead and copper were significantly higher in male sheep, which has been linked to the effect of androgens on metabolism.

Dr Sneddon comments, "Sheep wool evidently has potential as a bio-indicator of naturally occurring heavy metal concentrations in upland areas, which have previously not been assessed in this way". Future studies are planned to assess how the age of the sheep, and where on the animal the wool is taken from, influence results. Furthermore, it is intended to use samples provided by the British Wool Marketing Board in order to provide regional and national focus to this work. In addition, it is hoped that sheep can be of future use in bio-remediation studies on brownfield sites.

Experimental method: A handful of wool was taken from shoulder area of rare and heritage breeds of sheep grazing on hills in the Lake District and North Wales. The wool was then washed to ensure that only metabolised deposits of heavy metals were detected, rather than anything that had stuck to the outside of the wool. Copper and lead concentrations were then determined using highly sensitive equipment which can accurately detect very small quantities of heavy metals. This was compared with data from local streams for accuracy.

###

This work will be presented as Poster A12.38 between Saturday 31st March – Monday 2nd April .
If using photograph please cite Dr Jennifer Sneddon as the photographer.
Examples of heavy metals are lead, copper, zinc and cadmium.
Bioindicators are species or chemicals used to monitor the health of an environment or ecosystem.
An androgen is a compound that controls the development and maintenance of masculine characteristics.
Brownfields are abandoned, idled, or under-used industrial and commercial facilities where expansion or redevelopment is complicated by real or perceived environmental contaminations.
The British Wool Marketing Board operates a central marketing system for UK fleece wool with the aim of achieving the best possible net returns for farmers.
Direct scientist contact
Contactable during the meeting via SEB Press Officer.
Before the meeting: E-mail: J.C.Sneddon@ljmu.ac.uk

This work will be presented at the Society for Experimental Biology’s Annual Meeting (30th March – 4th April 2007) at the Scottish Exhibition and Conference Centre, Glasgow, UK.

Journalists are welcome to attend the meeting. For full details of the programme please visit: http://www.sebiology.org.uk/Me.....amp;id=738
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PostPosted: Thu May 31, 2007 9:46 am    Post subject: Mercury's Link to Heart Disease Begins in Blood Vessel Walls Reply with quote

Mercury's Link to Heart Disease Begins in Blood Vessel Walls
Posted 5/30/2007
Ohio State University

COLUMBUS, Ohio – Heavy metals and other toxins have been linked to many human diseases, but determining exactly how they damage the body remains a mystery in many cases. New research focusing on a relatively obscure, misunderstood protein suggests mercury’s link to heart disease can be traced to activation of this enzyme, which triggers a process leading to plaque buildup in blood vessel walls.

The study examined three forms of mercury, matching its characteristics in the environment. Each form of mercury caused changes in the behavior of cells that line the blood vessel walls and that can lead to cardiovascular diseases.

The study also suggests that chelation therapy, a process that removes metals from the body, and antioxidants both show signs of suppressing this activity and might be key to reducing the damage caused by mercury, and possibly other heavy metals.

The research was published in a recent issue of the International Journal of Toxicology.

“Mercury has been implicated as a risk factor in cardiovascular disease because of environmental concerns both from contamination and the atmosphere. But no one has looked at heavy metal regulation of this enzyme,” said Narasimham Parinandi, director of the lipidomics and lipid signaling laboratory at Ohio State University Medical Center and senior author of the study. “If we understand this regulation and know how to block it, we can come up with proper ways to prevent the activity.”

Parinandi and colleagues focused on activation of an enzyme called phospholipase D, or PLD, in cells that line arteries in the lung. They exposed the cells to the inorganic, environmental and pharmaceutical forms of mercury, and observed that all three forms activated the enzyme.

The activation of the enzyme involves a complex sequence of events in the cell membranes that in turn releases phosphatidic acid, which can damage cells in the vessel lining – called endothelial cells – and is believed to contribute to vascular disorders.

To further test the enzyme’s role in blood vessel lining damage, the scientists then showed that metal chelators and antioxidants lessen the mercury-induced activation of the enzyme in endothelial cells. This portion of the study showed that different types of mercury affect the cells in different ways.

In the three forms of mercury – methylmercury chloride, (environmental form), thimerosal (pharmaceutical form) and mercuric chloride (inorganic form) – the enzyme activation was prevented by metal chelators, which are organic chemicals that bind with and remove free metal ions from substances.

The power of methylmercury chloride to activate the enzyme was also affected by antioxidants, including vitamin C, suggesting that this form of the metal generates free radicals. This is the form of mercury most closely associated with the food supply.

“Chelators overall did a better job than antioxidants at protecting against mercury activation of the enzyme,” said Thomas Hagele, first author of the study and an undergraduate researcher in Parinandi’s lab. “This shows that activation of the enzyme is not isolated to one location in the cell. Since we can protect against the enzyme activation with both chelators and antioxidants, that means a few different types of activation are likely to occur, depending on the toxin.”

This research is not just about mercury, noted Parinandi, also an assistant professor of pulmonary, critical care and sleep medicine. Mercury in this case acts as a model for other toxins that have similar effects on blood vessel walls, pointing to what happens in the body when toxic substances are a factor in causing diseases.

This research was supported by the National Institutes of Health.

Other Ohio State coauthors of the study are students Jessica Mazerik, Anita Gregory and Bruce Kaufman; Drs. Ulysses Magalang and Clay Marsh of pulmonary, critical care and sleep medicine; and Periannan Kuppusamy and M. Lakshmi Kuppusamy of the Davis Heart and Lung Research Institute.
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PostPosted: Thu Jun 28, 2007 8:24 am    Post subject: Plan to Dump Iron in Ocean Criticized Reply with quote

Plan to Dump Iron in Ocean Criticized
By Andrea Thompson, LiveScience Staff Writer

posted: 27 June 2007 01:23 pm ET

A controversial plan to dump iron dust into the open ocean near the Galapagos Islands to induce the growth of phytoplankton met with opposition from an environmental group today.

The plan, from a company called Planktos, Inc., seeks to grow the tiny creatures in an attempt to suck up excess atmospheric carbon dioxide.

Iron dust can stimulate the growth of microscopic marine plants that in turn use carbon dioxide taken from the atmosphere to fuel photosynthesis.

While phytoplankton in the ocean already absorb some of the greenhouse gas, some scientists have theorized that dumping iron into the ocean could allow it to become a more effective carbon sink, which is exactly the idea that Planktos, Inc, a for-profit company, plans to test.

For the full article:

http://www.livescience.com/env.....nktos.html
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PostPosted: Tue Jul 03, 2007 9:24 am    Post subject: Manganese levels increase in scrapie-infected sheep before c Reply with quote

Press Release - 02 July 2007
University of Bath

Manganese levels increase in scrapie-infected sheep before clinical symptoms develop

Sheep infected with scrapie and cows infected with BSE have elevated levels of manganese in their blood before clinical symptoms appear, according to new research.

The findings, published in the Journal of Animal Science, also show that scrapie-resistant sheep produce elevated levels of the metal when “challenged” with the disease.

This suggests that elevated manganese levels in the blood and central nervous system are caused by the animal’s initial response to the disease.

The findings raise the possibility of using manganese levels in the blood as a potential diagnostic marker for prion infection. At present, only post-mortem examination of the brain tissue gives a certain diagnosis.

Scrapie, Bovine Spongiform Encephalopathy (BSE) and Creutzfeldt-Jakob Disease (CJD) are neurodegenerative diseases that affect the brain and nervous system of sheep, cows and humans respectively.

They are transmitted by mis-formed prion proteins which cause tiny loss of brain cell in different regions of the brain, leading to impairment of brain function, including memory changes, personality changes and problems with movement that worsen over time.

“Definite diagnosis of prion disease is currently only possible post-mortem," said Professor David Brown from the University of Bath who led the study with colleagues from the universities of Hull and Edinburgh.

“These findings suggest that elevated blood manganese could be used as a robust diagnostic marker for prion infection, even before the onset of apparent clinical disease.

“In practice, however, it would be difficult implement a widespread screening programme, given that the mass spectrometry we use to measure levels is expensive and labour intensive.”

The research builds on the 2002 discovery that mice infected with scrapie have higher levels of manganese. This is the first time that tissue from farm animals infected with prion diseases have been studied in this way.

One of the most interesting findings from this study came from the analysis of blood samples from scrapie-resistant sheep.

When challenged with the disease, these sheep showed similar levels of manganese as non-resistant sheep challenged in the same way.

“Elevated levels of manganese in scrapie-resistant sheep imply that the change in blood manganese is a result of the scrapie challenge and not a consequence of scrapie pathology,” said Professor Brown, from the University of Bath’s Department of Biology & Biochemistry.

“Although these sheep are considered to be resistant to scrapie, they do show some indications that scrapie challenge results in similar metabolic changes as occur in non-resistant sheep.”

Another interesting finding was that although levels of manganese were elevated, there were differences in the blood levels of selenium and molybdenum in experimental and field cases of BSE in cows.

This suggests that the way a cow acquires the disease affects the metabolic processes involved.

“The origin of the increased manganese in the brains and blood of infected animals remains unknown,” said Professor Brown.

“The three possibilities are that there is decreased secretion of manganese from the body, release of manganese from other tissues or increased absorption of manganese from the environment.

“Currently there is insufficient evidence to favour any of these three theories.”



The University of Bath is one of the UK's leading universities, with an international reputation for quality research and teaching. In 16 subject areas the University of Bath is rated in the top ten in the country. View a full list of the University's press releases: http://www.bath.ac.uk/news/releases
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PostPosted: Thu Jul 05, 2007 12:06 pm    Post subject: Common environmental chemicals in diet affect fetal ovarian Reply with quote

European Society for Human Reproduction and Embryology
4 July 2007

Common environmental chemicals in diet affect fetal ovarian development

Lyon, France: Exposing a developing female sheep fetus to low doses of chemicals commonly present in the environment can disturb the development of the ovary, a scientist told the 23rd annual conference of the European Society of Human Reproduction and Embryology today (Wednesday 4 July). Dr. Paul Fowler, of the University of Aberdeen, Scotland, UK, said that this research would help to establish the importance of the effect of environmental chemicals for fertility.

Over recent decades there has been a dramatic increase in the production of industrial and agricultural chemicals and heavy metals, and this has coincided with widespread reports of breeding problems in wild animals. Fertility also appears to be declining among humans and there has also been a rise in reproductive defects observed in newborn babies.

Until now, most studies have looked at a short-lived exposure to high doses of single compounds, and have usually done so in mice and rats. Dr. Fowler and his colleagues decided to study the effect of long-term, low-level exposure to a cocktail of chemicals and heavy metals in an animal which has a long pregnancy, therefore better replicating the situation in the human.

“Our ‘real life’ model exposed developing sheep fetuses by pasturing their mothers on fields fertilised with either inorganic fertiliser, the control group, or, in the case of the treatment group, with digested human sewage sludge, before and during pregnancy”, said Dr. Fowler.

“ We examined the ovaries from the fetuses at day 110 of gestation, the equivalent of week 27 in a human pregnancy, and found that the ovaries from the fetuses where the mother was grazing the sewage sludge fields contained fewer eggs and also a number of protein abnormalities. These differences could have implications for problems such as cancer in later life.”

The scientists hope that their Wellcome Trust-funded study will help to pinpoint the stages of pregnancy at which the developing fetus is most sensitive to disruption and also to measure the degree to which fertility is affected in the offspring after puberty, following their exposure as fetuses to environmental concentrations of a mixture of pollutants. “Switching some mothers from sewage sludge fertilised to control pastures before conception will tell us whether maternal exposure either before or during pregnancy does most damage to the offspring”, said Dr. Fowler. “The sheep model is quite novel, with relatively little research in the area currently being performed in this way. One of the collaborators in the project, Professor Richard Sharpe from the MRC Human Reproductive Sciences Unit in Edinburgh, UK, has already found reduced testosterone and testis cell numbers in the male fetus exposed to sewage sludge at day 110 of gestation.

The group has applied for further funding to look more closely at the implications of the sheep findings for humans, for instance by comparing quantities of chemicals in the human fetus with those seen in sheep, and investigating whether changes induced in the sheep fetus could be a problem for the developing human. They also intend to look at the mechanisms by which exposure to environmental chemicals can cause defects in reproductive development in order to determine what might be done to reduce risks for the human fetus.

There is still considerable debate around the level of importance of environmental chemicals in cancer, obesity, infertility and other complex diseases which have multiple causes. “We hope our research will help in the drive for evidence-based policy making on this issue”, said Dr Fowler. “If we can definitely establish that environmental chemicals are important in triggering these diseases, then we might be able to produce better treatments, but it would also be important to devise legislation to begin reducing the levels of such chemicals. We would then look to work with chemical and agricultural industries to find safer chemicals by improving how they assess fetal development effects. If such measures helped to reduce the rates of cancer, obesity and infertility, there would be considerable benefits in terms of the costs of healthcare.”
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PostPosted: Mon Jul 09, 2007 8:09 am    Post subject: 'Green' Light Bulbs Pack Toxic Ingredient Reply with quote

'Green' Light Bulbs Pack Toxic Ingredient
By Andrea Thompson, LiveScience Staff Writer

posted: 09 July 2007 08:41 am ET

Highly efficient fluorescent light bulbs are widely touted as environmentally friendly, but they have created a recycling headache for the EPA and local governments. More often than not, their toxic ingredients simply end up in landfills, where the chemicals can leach into soil and water and poison fish and other wildlife.

The bulbs contain mercury and should not be tossed in the trash like regular light bulbs.

“They’re very efficient, but once they’re used up they become a ticking toxic time bomb," said Leonard Robinson, chief deputy director of the California Department of Toxic Substances Control. "They need to be captured and recycled."

The bulbs remain a good choice for the environmentally conscious, however, because the amount of mercury they contain is less than what is generated in the production of the extra electricity required to light an incandescent bulb.

For the full article:

http://www.livescience.com/env.....rcury.html
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PostPosted: Mon Jul 23, 2007 9:38 am    Post subject: Automobile brake linings, tires remain major sources of toxi Reply with quote

Automobile brake linings, tires remain major sources of toxic metals
23 July 2007
Environmental Science & Technology

Particles worn away from automobile brake linings and tires continue to be major sources of potentially toxic metal emissions in urban areas, despite new regulations and auto industry efforts to reduce use of the metals, researchers in Sweden conclude in a report scheduled for the August 1 issue of ACS’ Environmental Science & Technology, a semi-monthly journal.

In the study, David S. T. Hjortenkrans and colleagues compared metal emissions from brake linings and tires to other metal emission sources in Stockholm during 1995 and from 1998-2005. During this period, copper and zinc emissions from brake linings remained relatively unchanged at high levels that make them a major source of these metals, the researchers said. Brake linings were also a source of another toxic metal, antimony. By contrast, lead and cadmium emissions from brake linings decreased by one-tenth during this period.

The study found that metal emissions from tire tread rubber declined between 1995 and 2005, as manufacturers reduced metal concentrations in tire treads. Tires, however, remained one of the largest sources of zinc and an important source of cadmium. “As Stockholm represents a rather average city in most respects, the results from this study may be relevant for many other urban areas,” the report stated.

ARTICLE #3 FOR IMMEDIATE RELEASE
“Metal Emissions from Brake Linings and Tires: Case Studies of Stockholm, Sweden 1995/1998 and 2005”

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PostPosted: Mon Aug 06, 2007 12:06 pm    Post subject: Toward faster tests to identify carcinogens and other enviro Reply with quote

Toward faster tests to identify carcinogens and other environmental toxins
Chemical & Engineering News
6 August 2007

After years of frustration with traditional methods for testing the toxicity of chemicals in the environment, scientists are working to adapt faster, simpler screening methods that do not require animals, now used by the pharmaceutical industry to identify potential drug candidates, according to an article [insert link here] scheduled for the August 6 issue of Chemical & Engineering News (C&EN), ACS’s weekly newsmagazine.

The article, written by C&EN Senior Editor Celia Henry Arnaud, explains that animal testing long has been the gold standard for environmental toxicology. But such tests take years to complete, can’t always be confidently extrapolated to humans, and require the use of laboratory animals. As a result, only a handful of commercial chemicals have gone through the complete battery of tests used by the Federal Government’s National Toxicology Program in its most thorough toxicology investigations.

Arnaud explains how environmental toxicologists are eyeing an attractive alternative — the so-called high-throughput screening methods that pharmaceutical companies use to find potential drug candidates within libraries of compounds. “If successful, such assays may in the short term reduce the animal toxicity tests that are necessary and in the long term replace animal tests entirely,” the article states. It points out, however, that formidable challenges lie ahead in adapting those tests for accurately predicting which commercial chemicals are potential human health threats.

ARTICLE #5 EMBARGOED FOR 9 A.M., EASTERN TIME, Aug. 6, 2007
“Toward Toxicity Testing Without Animals: High-throughput methods from pharma could reduce need for animals when assessing toxicity of chemicals in the environment”

This story will be available on August 6, at http://pubs.acs.org/cen/science/85/8532sci1.html
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PostPosted: Sat Sep 22, 2007 10:10 am    Post subject: Welcome to toxipedia, the free toxicology encyclopedia Reply with quote

Welcome to toxipedia, the free toxicology encyclopedia and resource center concerning the health effects of chemicals. You can learn more about toxipedia, by reading our vision, mission, goal, need statement and general description statements. We are seeking comments on our quality assurance program. We are non-profit organization with an advisory board. We are a small staff, but looking to grow so funding ideas are welcome.

http://toxipedia.org/conf/disp.....+Toxipedia
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PostPosted: Sun Sep 23, 2007 7:12 am    Post subject: Palladium and platinum an easier find with Pitt researcher's Reply with quote

University of Pittsburgh
22 September 2007

Palladium and platinum an easier find with Pitt researcher's detection method

Multipurpose metal used in cars, medicine, and alternative energy production

PITTSBURGH--Finding uses for palladium and platinum--rare precious metals coveted by the automobile, chemical, and pharmaceutical industries as catalysts in chemical reactions-proves easier than finding the scarce materials themselves.

Detection involves expensive instruments operated by highly trained chemists that take days to return results. But chemists at the University of Pittsburgh have unearthed a fast, easy, and inexpensive method that could help in the discovery of palladium/platinum deposits and streamline the production of pharmaceuticals. The research will be published online Sept. 21 in the Journal of the American Chemical Society.

The new method was developed in the laboratory of Kazunori Koide (Ko-ee-deh), a chemistry professor in Pitt's School of Arts and Sciences. It relies on a colorless fluorescein-based solution (similar to that used to find blood residue at crime scenes) that--under a simple hand-held ultraviolet lamp--glows green when it comes in contact with even minute amounts of palladium and platinum, which coexist in nature. The process takes approximately one hour as opposed to the effective but complex and days-long analysis currently employed in the mining and pharmaceutical industries, Koide explained. Moreover, the Pitt team's method can accommodate hundreds of samples at once whereas current technology analyzes samples only one at a time, Koide said.

"Our method can be used on the mining site," he said. "And you don't need a doctorate in chemistry-anyone can do this."

A major pharmaceutical company is currently evaluating Koide's method in detecting trace amounts of palladium in drug samples, Koide said. Although crucial in drug development, residual palladium in pharmaceuticals can be toxic, which means stringent chemical analysis is required to find this metal. Shortening the analysis to an hour will help get drugs to market faster and, in mining, find viable quantities of these essential metals.

Palladium and platinum are practically unmatched as catalysts and thus important to the chemical, pharmaceutical, and automobile industries (both are popular as jewelry, too). Palladium is most used in the catalytic converters that render car exhaust less toxic. But known palladium/platinum deposits dot only a few countries-including the United States and Canada-which makes the prices and supply unstable.
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PostPosted: Thu Nov 08, 2007 5:11 pm    Post subject: Paying peanuts for clean water Reply with quote

Inderscience Publishers
8 November 2007


Paying peanuts for clean water

Peanut husks could be used clean up waste water
Peanut husks, one of the biggest food industry waste products, could be used to extract environmentally damaging copper ions from waste water, according to researchers in Turkey. Writing in the Inderscience publication the International Journal of Environment and Pollution, the team describes how this readily available waste material can be used to extract toxic copper ions from waste water. The discovery offers a useful alternative to simple disposal of this ubiquitous food industry waste product.

Copper is an essential trace element found in many living organisms, but at high levels it is potentially harmful and when discharged at high concentration into natural water resources could pose a serious environmental threat to marine ecosystems. Various industries produce waste water containing dissolved copper(II) ions, including those that carry out metal cleaning and plating, paper pulp, paper board mills, and wood pulp production sites and the fertilizer industry.

Conventionally, various relatively sophisticated processes including copper salt precipitation, ion exchange, electrolysis, and adsorption on expensive activated carbon filters are used to remove copper ions from waste water.

Now, Duygu Özsoy and colleagues in the Department of Environmental Engineering, at Mersin University, Turkey, have begun investigating the potential of several materials to absorb the dissolved form of copper from waste water. They have looked at how well untreated peanut husks and another potential cleanup material, pine sawdust, compare in absorbing copper ions from waste water.

The team measured the levels of copper ions that could be extracted from waste water at different temperatures, acidity, flow rate, and initial concentration of dissolved copper.

They found that, as expected the longer the waste water is exposed to the materials the more efficient the process. However, there is a stark difference between peanut husk extraction and pine sawdust. The peanut husks could remove 95% of the copper ions whereas the pine sawdust only achieved 44% extraction. Efficiency works best if the water is slightly acidic but temperature had little effect on efficiency.

The researchers conclude that both untreated peanut husks, a cheap waste product of the food industry and pine sawdust from the timber industry could be used in waste water cleanup to reduce significantly levels of toxic copper levels.
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PostPosted: Tue Dec 18, 2007 3:31 pm    Post subject: Dead Stuff Makes Mercury More Deadly Reply with quote

Dead Stuff Makes Mercury More Deadly
By Andrea Thompson, LiveScience Staff Writer

posted: 18 December 2007 07:47 am ET

SAN FRANCISCO—It is well known nowadays that people should be careful around broken thermometers and moderate their consumption of tuna to avoid contact with mercury, a highly potent neurotoxin.

Now, scientists have figured out one of the things that makes water-borne mercury even more toxic—dead stuff.

For the full article:

http://www.livescience.com/env.....rcury.html
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PostPosted: Mon Jun 02, 2008 12:12 pm    Post subject: Lead leaching and faucet corrosion in PVC home plumbing Reply with quote

Lead leaching and faucet corrosion in PVC home plumbing
2 June 2008
Environmental Science & Technology

Scientists in Virginia are reporting that home plumbing systems constructed with polyvinyl chloride (PVC) plastic pipes may be more susceptible to leaching of lead and copper into drinking water than other types of piping —¬ especially when PVC systems include brass fixtures and pipefittings. The study is scheduled for the June 15 issue of ACS’ Environmental Science & Technology, a semi-monthly journal.

Marc Edwards and colleagues point out that more water purification plants in the United States are using chloramine to treat water. At the same time, builders are plumbing more houses with plastic pipe, rather than copper, to cut costs. Past studies have found that ammonia formed in chloramine-treated water can trigger a series of events that corrode brass faucet components and connectors commonly used in PVC plumbing systems. Corrosion of brass (made with copper, zinc and lead) releases those metals into water pipes and makes faucets prone to failure.

In the new study, researchers sampled water from polyvinyl chloride (PVC), copper, lead, and other pipe material under a range of experimental conditions. They found that corrosive conditions were often worst in plastic pipes, which could be expected to cause higher metal leaching of zinc and lead from brass faucets used in homes and buildings. — AD

ARTICLE #1 FOR IMMEDIATE RELEASE
“Nitrification in Premise Plumbing: Role of Phosphate, pH and Pipe Corrosion”

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