December 16, 2019
Enjoy these interesting stories from the scientific community.
*-- Household dust hosts toxic chemicals from LCD screens --*
Liquid crystal monomers are used to make a variety of electronics, including smartphones, televisions, computer displays and solar panels. New research suggests these materials contain a variety of toxic chemicals, which tests showed can leach into everyday environs.
"These chemicals are semi-liquid and can get into the environment at any time during manufacturing and recycling, and they are vaporized during burning," lead researcher John Giesy, an environmental toxicologist at the University of Saskatchewan in Canada, said in a news release. "Now we also know that these chemicals are being released by products just by using them."
For the new study, Giesy and his international team of research partners looked at the chemicals used in 362 of the most common liquid crystal monomers, surveying the scientific literature for evidence of each chemical's toxicity.
The scientists also identified several monomers featuring chemicals hazardous to animals and the environment in six of the most popular smartphone models.
In the lab, animals exposed to several of the toxic monomer ingredients were unable to properly digest nutrients. The chemicals also exhibited characteristics known to interfere with the functioning of the gallbladder and thyroid glands.
The harmful qualities observed among monomer chemicals resembled those found among dioxins and flame retardants, chemicals that are known to be toxic to humans and animals.
"We don't know yet whether this a problem, but we do know that people are being exposed, and these chemicals have the potential to cause adverse effects," said Giesy.
To help quantify exposure levels, scientists tested dust samples from a variety of buildings in China -- in student dorms, a classroom, a hotel, several homes, a science lab and an electronics repair shop.
Almost half of all the dust samples tested positive for liquid crystal polymers. Scientists described the prevalence of liquid crystal monomers and their toxic components this week in the journal PNAS.
"Ours is the first paper to list all of the liquid crystal monomers in use and assess their potential to be released and cause toxic effects," said Giesy. "We looked at over 300 different chemicals and found that nearly 100 have significant potential to cause toxicity."
In addition to having potentially toxic effects on animal and human health, the chemicals found in liquid crystal monomers also feature a variety of worrisome qualities. Many of the chemicals accumulate in organisms, are slow to degrade and can travel long distances through the atmosphere.
Now that scientists know these chemicals are making their way into the environment, scientists now plan to figure out how they move and where they go.
"Right now, there are no measurements of these monomers in surface waters. Our next steps are to understand the fate and effect of these chemicals in the environment," said Giesy.
*-- ESA to fund world's first space debris removal mission --*
The European Space Agency has agreed to fund a mission to remove a piece of space debris -- the first of its kind -- as part of the agency's new Space Safety program.
The mission, announced Monday, will be executed by a consortium of aerospace companies, led by the Swiss startup Clearspace, which was founded by a group of space debris researchers working at the Ecole Polytechnique Fédérale de Lausanne research institute, EPFL.
ESA expects the mission to launch in 2025.
"This is the right time for such a mission," Luc Piguet, founder and CEO of ClearSpace, said in a news update from ESA. "The space debris issue is more pressing than ever before. Today we have nearly 2,000 live satellites in space and more than 3,000 failed ones."
Currently, scientists with the U.S. military and space agencies around the globe use tracking data and probability models to help active government-owned and private satellites avoid pieces of junk. But the problem of space debris is getting worse.
The growth of the private space industry and the shrinking of satellite technology has made it cheaper and easier to launch a satellite than ever before. Every year, hundreds of new satellites are sent into space.
Many experts predict low Earth orbit will eventually become so crowded that more interventionist methods will be necessary -- in other words, debris removal.
To demonstrate the feasibility of space debris removal, engineers with the ClearSpace-1 mission will launch a four-armed robotic junk collector to retrieve Vespa, a small satellite launched by ESA in 2013. Vespa, though defunct, remains in orbit around Earth at a distance of 497 miles.
At a meeting held in Seville, Spain, at the end of November, ESA leaders agreed that the growing problem of space junk required action.
"Imagine how dangerous sailing the high seas would be if all the ships ever lost in history were still drifting on top of the water," said ESA Director General Jan Wörner. "That is the current situation in orbit, and it cannot be allowed to continue. ESA's Member States have given their strong support to this new mission, which also points the way forward to essential new commercial services in the future."
Space agencies, aerospace companies and a variety of research institutions continue to work to improve guidelines for space launches in order minimize the impacts of new satellites and spacecraft on low Earth orbit congestion.
But even if all launches were called off today, low Earth orbit will continue to get increasingly dangerous for active satellites. When pieces of debris collide and break apart, the shrapnel scatters and increases the odds of future collisions -- a cascading effect.
Data collected by the U.S. government shows congestion in low Earth orbit gets worse every day.
"We're at a tipping point right now," John Crassidis, a professor of mechanical and aerospace engineering at the University of Buffalo, told UPI earlier this year.
Some space junk experts suggest low Earth orbit, LEO, could become overwhelmed by space debris within 50 years.
Once the ClearSpace-1 mission probe grabs Vespa, it will fall back into Earth's atmosphere and burn up. Such a technique for debris removal isn't economically sustainable. Experts hope future cleanup probes will be able to grab a piece of junk, deposit into the atmosphere and continue on to collect more debris.
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