You are currently browsing the daily archive for July 28th, 2009.
A new study shows that plastic lab equipment can interfere with experiments.
by Andrew Grant
From the February 2009 issue, published online January 30, 2009
Image: Flickr / skycaptaintwo
Concerned parents have switched from plastic to metal water bottles to protect their kids from bisphenol A and phthalates, plastic-hardening chemicals suspected of posing health risks. Now a study in Science [subscription required] reveals that plastics may also be a problem in the lab: Compounds purposely embedded in plastic lab equipment—to prevent bacteria from growing and to lower the melting temperature—can taint complex biological experiments, potentially skewing the results. For instance, pharmacologist Andrew Holt and his team at the University of Alberta in Canada recently discovered that chemicals released from disposable plastic test tubes interfered with a Parkinson’s drug they were testing by binding to the gamma-aminobutyric acid proteins in the experiment. Such effects have not been seen beyond a handful of instances, but for now, Holt says, researchers may want to switch to glass instruments.
Source: http://discovermagazine.com/2009/feb/30-plastic-messing-up-science-itself
A new political fight is brewing over where to locate a mercury storage facility, as state officials and residents around the seven sites in consideration have grown alarmed at the prospect of the federal government forcing thousands of casks of the toxic metal on them. Ironically, the conflict began when the federal government passed a law to forbid sending the dangerous metal abroad, but nobody seems eager to keep it at home.
Last year, then-Senator Barack Obama sponsored a bill to bar mercury exports beginning in 2013, and President Bush signed it. The bill also requires the Department of Energy to identify a safe, long-term storage site for up to 17,000 tons of mercury, which is so dense that it would fill less than half of an Olympic-size swimming pool. That includes stockpiles held by the federal government, as well as commercial supplies [AP]. The seven sites in consideration for the storage facility are scattered across the country, in South Carolina, Missouri, Colorado, Nevada, Idaho, Texas, and Washington.
Mercury can cause serious developmental problems in children, and can also impair cognitive and motor functions in adults. While this dangerous neurotoxin is being phased out by industry and the government here in the United States, surplus mercury is shipped overseas to developing countries, where it is released from highly polluting industries…. “Not only is the air and water in those importing countries contaminated with concentrations of mercury that would not be tolerated in the United States, the mercury can also travel for thousands of miles and can settle right back here in the United States, poisoning Americans mainly through consumption of contaminated fish” [Environmental News Service], explained Susan Keane, a scientist for the Natural Resources Defense Council.
Protests regarding the proposed storage facility have already popped up in each area that’s under consideration. The city council of Kansas City, Missouri has passed a resolution opposing the facility, while the angry Idaho governor vowed to fight it. But some say the facility would pose no danger. Opponents of the proposal made it sound as though it called for mercury to be poured into a hole in the ground, said Jack Kingsley, a retired physicist. Mercury “is not that hard to seal up,” Kingsley said. “A lot of the concerns have been overblown.” Plans call for the construction of a building of about 150,000 square feet that would hold thousands of 76-pound steel flasks, each containing 2.5 liters of the liquid, silvery metal…. The building, which would look much “like a Wal-Mart or a Costco,” would have sealed concrete floors that would contain any leaks, said David Levenstein of the Energy Department [Grand Junction Sentinel].
Related Content:
80beats: Andean People Discovered Mercury Mining—and Mercury Pollution—in 1400 B.C.
80beats: FDA Report: Fish Is Good for Brains Despite Mercury Risk
DISCOVER: Our Preferred Poison, mercury is everywhere
DISCOVER: Do You Really Want to Eat That Tuna?
DISCOVER: How to Tell If You’re Poisoning Yourself With Fish
Image: iStockphoto
Source: http://blogs.discovermagazine.com/80beats/2009/07/27/where-to-put-thousands-of-casks-of-toxic-mercury-not-in-my-backyard/
To stop the spread of the Sahara Desert, one innovative thinker has proposed a bold plan: a wall along the southern border of the desert that would hold back the advancing dunes. Swedish architect Magnus Larsson says the wall would effectively be made by “freezing” the shifting sand dunes, turning them into sandstone. “The idea is to stop the desert using the desert itself,” he said. The sand grains would be bound together using a bacterium called Bacillus pasteurii commonly found in wetlands.” It is a microorganism which chemically produces calcite – a kind of natural cement” [BBC News].
Larsson is already well-known in the field thanks to his proposed Great Green Wall, a 4,349 mile line of trees stretching across Africa to stop desertification [Fast Company]. The sandstone wall could compliment the green wall, Larsson says, because if people chopped down the trees for firewood the sandstone wall would still remain.
The architect unveiled his proposal at the TEDGlobal conference in Oxford, dedicated to “ideas worth spreading.” Larsson explained that the bacterium would get into the dunes either by injecting it (on a massive scale) or by giant balloons filled with it — these would be place in the way of the moving dunes, which would wash over the balloons, which in turn would be popped allowing the bacteria to get into the sand [Treehugger].
Larsson acknowledges that the scheme faces political, practical, financial, and ethical challenges. “However, it’s a beginning, it’s a vision; if nothing else I would like this scheme to initiate a discussion,” he added [BBC News].
Related Content:
80beats: Architects Propose Fantastic Greenhouses Across the Sahara
80beats: A Solar Power Plant in the Sahara Could Power All of Europe
DISCOVER: How to Make a Desert
Source: http://blogs.discovermagazine.com/80beats/2009/07/27/can-bacteria-create-a-cement-wall-to-hold-back-the-sahara/
European Union officials say they’re considering an ambitious plan to draw energy from the sun that beats down relentlessly on the Sahara. By building a solar power plant the size of Wales (a small area, compared to the vastness of the Sahara) and laying down high-voltage transmission cables, the EU could potentially capture enough clean energy to power the entire continent.
Speaking at the Euroscience Open Forum in Barcelona, Arnulf Jaeger-Walden of the European commission’s Institute for Energy, said it would require the capture of just 0.3% of the light falling on the Sahara and Middle East deserts to meet all of Europe’s energy needs [The Guardian]. It’s more efficient to build such a system in the desert, officials say, because the intense sunlight of North Africa can produce three times more electricity than a similar set-up in Northern Europe.
The solar farms would produce electricity either through photovoltaic cells, or by concentrating the intense desert heat to boil water and drive turbines. This, along with power from other renewable sources, such as wind or geothermal, would be fed into a 5,000-mile electricity supergrid, stretching from Siberia to Morocco and Egypt to Iceland [Telegraph]. The plan comes with a high pricetag–the supergrid alone is estimated to cost $70 billion–but it would help the EU meet its target of reducing greenhouse gas emissions 20 percent by 2020.
This supergrid proposal has the support of British Prime Minister Gordon Brown and French President Nicholas Sarkozy, and supporters say the massive project would trump the unpredictability of the weather, which is often mentioned as a deterrent to relying on solar and wind energy. The wind would always be blowing somewhere, supporters say, and the sun shines on the Sahara pretty regularly.
Image: flickr/mtsrs
Source: http://blogs.discovermagazine.com/80beats/2008/07/23/a-solar-power-plant-in-the-sahara-could-power-all-of-europe/
A team of architects and environmental engineers has proposed covering swaths of the Sahara with vast “salt water greenhouses” powered by solar power arrays, in a plan they call the Sahara Forest Project. Charlie Paton, inventor of the salt water greenhouse, says the combined technologies could transform patches of the desert from arid wastelands into lush expanses that produce a bounty of fruits and vegetables for local people.
The plan is no doubt ambitious and unproved at this scale, but Paton says he has built demonstration greenhouses on the Spanish island Tenerife, as well as in Abu Dhabi and Oman; he says there is further interest in funding demonstration projects from across the Middle East, including UAE, Oman, Bahrain, Qatar and Kuwait. The cost is not as astronomical as one would think, and is estimated at approximately $118 million for a 20 hectare [50 acre] site of greenhouses and a 10MW concentrated solar power farm [Red Herring]. Paton is working with Exploration Architecture, a company that worked on the world’s largest greenhouse in England’s Eden Project.
The greenhouses work by using the solar farm to power seawater evaporators and then pump the damp, cool air through the greenhouse. This reduces the temperature by about 15C compared to that outside. At the other end of the greenhouse from the evaporators, the water vapour is condensed. Some of this fresh water is used to water the crops, while the rest can be used for the essential task of cleaning the solar mirrors. “So we’ve got conditions in the greenhouse of high humidity and lower temperature,” said Paton. “The crops sitting in this slightly steamy, humid condition can grow fantastically well” [The Guardian].
The project would use a concentrated solar power (CSP) system, in which huge mirrors focus the sun’s rays onto water heaters, which produces steam to power turbines. As the dreamers envision it, the Sahara Forest Project would be established near the north coast of Africa. The scheme has been designed as a ‘hedge’ of greenhouses providing a windbreak and shelter for the outdoor planting. CSP arrays will be placed at intervals along the greenhouse ‘hedge’. The greenhouses produce five time more fresh water than needed for the plants inside. This surplus will be used to irrigate the planted orchards and the Jatrophra [sic—the correct name is “Jatropha”] crop, which can be turned into bio-fuel for transportation and other needs [Treehugger].
Image: Exploration Architecture
Related Post: A Solar Power Plant in the Sahara Could Power All of Europe
Source: http://blogs.discovermagazine.com/80beats/2008/09/02/architects-propose-fantastic-greenhouses-across-the-sahara/
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