Archive | Radiation

Dress Rehearsals for Europa Missions Eyed

PASADENA, Calif., Aug. 17 (UPI) — Possible future missions to explore Jupiter’s moon Europa could have dress rehearsals at Earth sites that mimic the Jovian moon, U.S. researchers say.

Just as missions to Mars were carefully field-tested in “Mars yards,” earthly terrains that duplicated areas of the red planet, researchers would like to rehearse Europa missions here first, Astrobiology Magazine reports.

Landing and moving about on Europa, with its icy and cracked surface, could prove especially tricky, scientists say.

And amid debate over whether Europa might host alien life, scientists also would like to vigorously test methods that look for evidence of it.

“Before we can build landers, we need to understand these environments, and the interplay of biology and chemistry under these unusual conditions,” astrobiologist Damhnait Gleeson at NASA’s Jet Propulsion Laboratory said. “Designing missions to go to Europa presents many technical challenges, from the low temperatures to the harsh radiation.”

One Earth site that might mimic Europa is Lake Vostok in Antarctica.

Europa’s ocean probably lies beneath perhaps some 9.3 miles of ice. Similarly, Lake Vostok is located roughly 2.5 miles beneath the surface of the East Antarctic ice sheet.

No analog is a perfect match for Europa, Gleeson admits.

Still, “the similarities are more important than the differences in this case,” Gleeson said. “The more different sets of conditions we prepare for, the better our chances of being prepared for the unexpected at Europa.”

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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Effects of Russian Fires Weighed

MOSCOW, Aug. 13 (UPI) — As heat-driven fires continue to sweep across Russia, the country has begun to tally the health and environmental costs of the disaster, officials say.

A multitude of public health and environmental consequences face the country, including the risk of radioactive particles being released by fires in the contaminated zone near the Chernobyl nuclear reactor, an article in the journal Nature said Thursday.

More than 1,100 square miles of forest, vegetation and peat land have burned since the fires began in June. Russia’s ministry of health and social development says the death toll from the fires has risen to 53, with 806 people needing medical attention.

As the fires have burned closer to urban areas, they destroyed gardens and vegetable patches, Johann Goldammer, director of the Global Fire Monitoring Center, said.

“Many poor people will lose their harvest, which they need to survive the winter,” he says.

Long-term health effects are another concern, he said, as carbon monoxide pollution has risen to 10 times above the maximum permitted levels.

The fires also reached the Bryansk region east of Chernobyl, site of the 1986 nuclear power plant accident, raising fears that radioactive particles could be released into the atmosphere.

One British researcher discounts that possibility.

Most of the radioactive particles are in the soil rather than in the flammable leaf litter and trees, Jim Smith of the University of Portsmouth says.

Previous fires in the Chernobyl exclusion zone have resulted in an increase in radiation of less than 1 percent, he says.

“Only a small amount of radiation gets re-suspended, so I’m not concerned about damage from inhalation,” Smith says.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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Effects of Russian Fires Weighed

MOSCOW, Aug. 13 (UPI) — As heat-driven fires continue to sweep across Russia, the country has begun to tally the health and environmental costs of the disaster, officials say.

A multitude of public health and environmental consequences face the country, including the risk of radioactive particles being released by fires in the contaminated zone near the Chernobyl nuclear reactor, an article in the journal Nature said Thursday.

More than 1,100 square miles of of forest, vegetation and peat land have burned since the fires began in June. Russia’s ministry of health and social development says the death toll from the fires has risen to 53, with 806 people needing medical attention.

As the fires have burned closer to urban areas, they destroyed gardens and vegetable patches, Johann Goldammer, director of the Global Fire Monitoring Center, said.

“Many poor people will lose their harvest, which they need to survive the winter,” he says.

Long-term health effects are another concern, he said, as carbon monoxide pollution has risen to 10 times above the maximum permitted levels.

The fires also reached the Bryansk region east of Chernobyl, site of the 1986 nuclear power plant accident, raising fears that radioactive particles could be released into the atmosphere.

One British researcher discounts that possibility.

Most of the radioactive particles are in the soil rather than in the flammable leaf litter and trees, Jim Smith of the University of Portsmouth says.

Previous fires in the Chernobyl exclusion zone have resulted in an increase in radiation of less than 1 percent, he says.

“Only a small amount of radiation gets re-suspended, so I’m not concerned about damage from inhalation,” Smith says.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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Scientists Excited About Nova Explosion

WASHINGTON, Aug. 12 (UPI) — Astronomers say they’ve detected gamma rays from an exploding nova for the first time, a finding that overturns prevailing thought about such explosions.

A nova is a sudden, short-lived brightening when a white dwarf in a binary system erupts in an enormous thermonuclear explosion, but most scientists had believed such explosions were not powerful enough to emit high-energy gamma radiation, NASA said Thursday.

Gamma rays are the most energetic form of light, and NASA’s Fermi’s Large Area Telescope detected the nova for 15 days.

“In human terms, this was an immensely powerful eruption, equivalent to about 1,000 times the energy emitted by the sun every year,” Elizabeth Hays, a Fermi project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., said.

The white dwarf is about 9,000 light-years away, part of a so-called symbiotic binary containing a compact white dwarf and a red giant star about 500 times the size of the sun. More powerful supernovae explosions were known to generate gamma rays, but it was not thought smaller novae explosion were capable of it, NASA said.

Supernovae remnants endure for 100,000 years and affect regions of space thousands of light-years across, scientists say. One scientist compared astronomical studies of supernova remnants to looking at static images in a photo album.

“It takes thousands of years for supernova remnants to evolve, but with this nova we’ve watched the same kinds of changes over just a few days,” Kent Wood of the Naval Research Laboratory in Washington said.

“We’ve gone from a photo album to a time-lapse movie.”

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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N.Y. Nuclear Risk Assessment Described

WEST VALLEY, N.Y., Aug. 12 (UPI) — U.S. researchers have announced an improved method of predicting where people might be exposed to radiation from nuclear waste disposal sites.

Engineering and scientific experts associated with U.S. and New York state energy agencies focused on a buried nuclear waste disposal facility at West Valley, N.Y., a Society for Risk Analysis release said Wednesday.

Researchers say their study looked at possible scenarios, likelihoods and consequences of a threat to the disposal site and concluded “a release resulting in a dose of 100 millirems in one year, or more, is extremely unlikely during the next 30 years of operation of the state managed disposal area at the Western New York Nuclear Service Center.”

By comparison, the study said, the public is exposed to approximately 300 millirems a year of cosmic radiation in the atmosphere with no visible health effects.

Possible scenarios were considered involving hypothetical releases of radionuclides by liquid, solid or air pathways.

The scientific analysis supports a decision to continue management of waste at the site for another decade, the researchers said.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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For Some, Prostate Surgery Better

SAN FRANCISCO, Aug. 10 (UPI) — Surgery may be the best choice for prostate cancers likely to recur or spread, U.S. researchers suggest.

Researchers at the University of California, San Francisco, found the risk of cancer-specific mortality more than three times higher in patients receiving hormone therapy versus those whose prostate was surgically removed and more than twice as high in patients who received external-beam radiation therapy versus those having surgery.

The study, published in the journal Cancer, concluded the differences among therapies — when looking at long-term survival outcomes — were more prominent at the higher levels of cancer risk.

The study’s lead investigator, Dr. Matthew Cooperberg, pointed out there has been relatively little high-quality evidence on which to base current treatments.

“These therapies can all have significant side effects, so it’s important to understand which treatment alternatives are most effective,” Cooperberg says in a statement. “In current practice, likelihood of undergoing surgery falls progressively with increasing levels of risk, which may be exactly contrary to what the treatment pattern should be.”

Among men with prostate cancers at low levels of risk, Cooperberg and colleagues find very low prostate cancer mortality and treatment options differences were small.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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Smoking, Piercing Up Breast Abscess Risk

IOWA CITY, Iowa, Aug. 6 (UPI) — Breast abscesses, inflammatory lesions that are painful, appear at much higher rates in women who smoke or pierce their nipples, U.S. researchers say.

Dr. Vinod Gollapalli — a postdoctoral fellow in the department of surgery at the University of Iowa Carver College of Medicine in Iowa City, Iowa, says a breast abscess tends to recur at rates as high as 40 percent to 50 percent but until now there has been a lack of research on the risk factors associated with the condition.

Using surgical and radiologic databases at the University of Iowa Hospitals and Clinics, the researchers identified 68 patients with a diagnosis of breast abscess with no previous history of breast cancer, breast radiation therapy, or breast surgery within the past 12 months.

“Nearly 60 percent of patients with a recurrence of breast abscess were heavy smokers — 10 cigarettes a day,” Gollapalli says in a statement. “Since smoking appears to be a strong risk factor for both causing breast abscess and its recurrence, we recommend patients should be counseled to quit smoking as an integral part of treatment.”

The study was published in the Journal of the American College of Surgeons.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

Posted in History, Other, Radiation, Smoking0 Comments

Consistent All-over Tan a Myth

EDINBURGH, Scotland, Aug. 5 (UPI) — Some parts of the body are much more resistant to tanning than others, so a consistent all-over tan may be impossible, researchers in Scotland say.

Study leader Jonathan Rees of the University of Edinburgh says researchers analyzed the skin of 100 volunteers exposed to six doses of ultraviolet B on two areas of the body — the back and buttock.

In addition, the volunteers were given an injection to minimize the rush of blood that naturally occurs after the skin is exposed to sunlight in the first 24 hours. The redness is often confused with the start of a tan, but it is the skin’s signal that it has been damaged.

After seven days, the volunteers’ skin was analyzed to find what color remained after the redness faded.

The color — considered a suntan — comes from the skin’s production of melanin, a defense that blocks the skin from absorbing too much harmful UVB radiation.

The study, published in the journal Experimental Dermatology, found the buttock is much more resistant to sunshine and this may explain why it is so hard to get an even tan all over the body.

“One of the real puzzles about melanoma is why the numbers of tumors differ so much depending on body site,” the researchers said. “Our work shows that in one sense we are all made up of different units of skin, which respond differently to sunshine.”

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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Consistent All-over Tan a Myth

EDINBURGH, Scotland, Aug. 5 (UPI) — Some parts of the body are much more resistant to tanning than others, so a consistent all-over tan may be impossible, researchers in Scotland say.

Study leader Jonathan Rees of the University of Edinburgh says researchers analyzed the skin of 100 volunteers exposed to six doses of ultraviolet B on two areas of the body — the back and buttock.

In addition, the volunteers were given an injection to minimize the rush of blood that naturally occurs after the skin is exposed to sunlight in the first 24 hours. The redness is often confused with the start of a tan, but it is the skin’s signal that it has been damaged.

After seven days, the volunteers’ skin was analyzed to find what color remained after the redness faded.

The color — considered a suntan — comes from the skin’s production of melanin, a defense that blocks the skin from absorbing too much harmful UVB radiation.

The study, published in the journal Experimental Dermatology, found the buttock is much more resistant to sunshine and this may explain why it is so hard to get an even tan all over the body.

“One of the real puzzles about melanoma is why the numbers of tumors differ so much depending on body site, the researchers said. “Our work shows that in one sense we are all made up of different units of skin, which respond differently to sunshine.”

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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Green Lasers Can Present Eyesight Risk

WASHINGTON, Aug. 4 (UPI) — Green lasers, brighter than red lasers and a popular consumer item, could be a hazard by emitting dangerous levels of infrared radiation, U.S. researchers say.

Scientists at the National Institute of Standards and Technology testing inexpensive green laser pointers found some emitted almost twice the rated power level of light — but at invisible and potentially dangerous infrared wavelengths rather than green, an NIST release said Wednesday.

One pointer rated a 10 milliwatts delivered only weak green light but emitted infrared levels of almost 20 milliwatts, enough to cause retinal damage.

Tests of other laser pointers found similar intense infrared emissions.

The problem is caused by inadequate quality control in the manufacturing process, NIST researchers said.

If crystals in the pointer that generate the laser light are misaligned, they said, little of the light comes out as green and most of it comes out as infrared.

The problem could be solved with an inexpensive infrared filter at the end of the laser, which could reduce or block infrared emissions.

Although such filters are used in modern digital cameras and more expensive green laser pointers, they often are left out of the inexpensive models, the NIST said.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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