Thanks to NASA and emerging commercial space flight companies, there will likely be more astronauts in the future, and they’ll be traveling farther and more frequently into space. Space travel has known risks for bones, eyesight and other bodily systems, but a new study is the first to show that space travel could lead to Alzheimer’s disease l
ater in life.
Outside the protection of the Earth’s magnetic field, astronauts are exposed to cosmic radiation. These high-mass, highly-charged particles can penetrate solid objects—spaceships, astronauts and brains included.
The universe is more massive than it looks. Although it’s invisible to the eye, this extra mass, called dark matter, seems to interact with visible matter through gravity and the weak nuclear force. Some researchers hypothesize that dark matter consists of WIMPs, or weakly interacting massive particles, which form an invisible “sea” through which the Earth passes as our planet travels through space. While these WIMPs would ordinarily fly right through ordinary matter, we might be able to observe the rare occasions when one directly strikes a nucleus.
One big challenge to WIMP detection is proving that a collision was due to a WIMP, and not to another type of fly-by particle. Some projects are dealing with this problem by burying their detectors deep underground where no interfering radiation can reach; some are using the fact that the number of WIMP collisions is expected to change throughout each day and each year, as Earth’s position in the sea of WIMPS changes. (This approach is similar to the Michaelson-Morley experiment, which disproved the existence of luminiferous aether, another invisible “sea” we supposedly orbited through.) Now an interdisciplinary group of physicists and biologists has an idea to take the comparison of daily and annual measurements to the next level.
Two new reports on radiation doses received by workers and civilians near the Fukushima Daiichi nuclear meltdown last year indicate that there will be very little, if any, increase in their cancer risk.
The reports, put together by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and the World Health Organization and slated to be presented in Vienna this week, draw on all the available data about the crisis and include detailed information about exposure, according to Nature News, which has the exclusive:
[UNSCEAR] scoured anonymized medical data for 20,115 workers and contractors employed by the Tokyo Electric Power Company, which runs the plant. It found that 146 employees and 21 contractors received a dose of more than 100 millisieverts (mSv), the level at which there is an acknowledged slight increase in cancer risk. Six workers received more than the 250 mSv allowed by Japanese law for front-line emergency workers, and two operators in the control rooms for reactor units 3 and 4 received doses above 600 mSv, because they had not taken potassium iodide tablets to help prevent their bodies from absorbing radioactive iodine-131. So far, neither operator seems to have suffered ill effects as a result of their exposure.
The levels of exposure for civilians was much, much smaller, and neither employees nor civilians are expected to have statistically higher rates of cancer. But not everyone Nature News spoke to was totally at ease with the reports; after the way the Japanese government and energy utilities handled the disaster, many people are extremely distrustful of official estimates claiming that there is little risk:
Tatsuhiko Kodama, head of the radioisotope centre at the University of Tokyo and an outspoken critic of the government, questions the reports’ value. “I think international organizations should stop making hasty reports based on very short visits to Japan that don’t allow them to see what is happening locally,” he says.
Hugo Chavez, president of Venezuela, has speculated that the fact that he and four other South American leaders have all recently come down with various cancers could be a sign that the US has developed methods to give people cancer. Uh, is that even possible? Slate‘s Explainer does a thorough, interesting walk-through of all the reasons why the answer is, “Not reliably.”
You could…contaminate the victim’s diet with high levels of aflatoxin, which is associated with liver cancer. Or you could infect him with any of a number of cancer-causing biological agents. Helicobacter pylori contributes to the development of gastric cancer, and human papillomaviruses can cause cervical, anal, and a few other forms of cancer. But these tactics probably wouldn’t produce cancer in the short term and aren’t guaranteed to have any effect at all. In countries with high aflatoxin exposure, like China and parts of Africa, fewer than 1 in 1,000 people develop liver cancer.
If we knew how to give people cancer reliably, we might be better at preventing it. As it stands, cancer prevention, except for a few stand outs like quitting smoking, is can be just as hit-or-miss as cancer contraction.
Image courtesy of nicogenin / flickr
How do you do to measure radiation levels in the hard-to-reach forests near Japan’s Fukushima Daiichi plant? Why, fit wild monkeys with radiation sensors, of course! Researcher Takayuki Takahashi tells CNN that his team plans to fit three monkeys in early 2012 with collars that measure radiation, as well as GPS units that record location and distance from the ground. The researchers plan to leave the monitors in place for about a month, before detaching them via remote control and picking up them up to retrieve their stored data.
The nuclear disaster at the Fukushima Daiichi power plant this spring may have released twice as much radiation into the atmosphere as the Japanese government estimated, a new preliminary study says. While the government estimates relied mostly on data from monitoring stations in Japan, the European research team behind the new report looked at radioactivity data from stations scattered across the globe. This wider approach factored in the large amounts of radioactivity that were carried out over the Pacific Ocean, which the official tallies didn’t.
What’s the News: Japan raised its assessment of the severely damaged Fukushima Daiichi nuclear power plant to Level 7, “Major Accident,” the highest ranking on the International Atomic Energy Agency’s International Nuclear and Radiological Event Scale. The explosion at Chernobyl in 1986 is the only other nuclear accident to be ranked at Level 7. Both accidents were extremely severe, the two largest nuclear power accidents ever—but there are some big, important differences between them.
Humankind’s experience visiting worlds beyond our own begins and ends with the dozen Apollo astronauts who skipped about on tiny swaths of the moon. But that doesn’t mean we can’t experiment with how and where we might visit (or live) on the extreme surfaces of other worlds. A few studies out recently are doing just that.
Radiation? Big deal
Our planet provides a protective shield from the most damaging radiation produced by the sun—a shield not available on the moon or Mars. It’s a hazard for any human leaving the planet, and it’s a hazard for plants, too.
However, a new study of the Chernobyl area in the Ukraine, site of the famous nuclear accident, is actually raising hopes for space farming.
Even 25 years after the catastrophic nuclear accident at Chernobyl, the area around the site harbors radioactive soil. But researchers working there have found that oil-rich flax plants can adapt and flourish in that fouled environment with few problems. Exactly how the flax adapted remains unclear, but what is clear is that two generations of flax plants have taken root and thrived there, and that could have big implications for growing plants aboard spacecraft or on other planets at some point in the future. [Popular Science]
When you engage in a long cell phone conversation, a new study says, the phone radiation may increase the brain activity in regions nearest to the antenna. It’s the newest entry into the long-running debate about whether cell phones carry health risks, but the scientists behind the research in the Journal of the American Medical Association caution that they don’t know what this localized change in brain activity means—or even how it’s happening.
Many previous studies of cell phone safety have looked into the question of whether the phones’ radiation could cause cancer (there’s no solid evidence that it could) or looked at the effects of the heat that phones create. But Nora Volkow and colleagues investigated something else: The metabolism of the brain regions nearest to the phone—that is, how quickly they are burning energy. To do it, Volkow’s team recruited 50 people and subjected them to PET scans while an active cellphone sat next to their heads.
To blind the participants, the authors strapped two cell phones on their heads, one to each ear (the cellphone used in this work is a standard Samsung CDMA flip phone). Both were kept muted, and only one was activated by a call—the side that was activated was flipped in two different recording sessions. The calls started 20 minutes before a dose of radioactive glucose, and kept going for a half an hour afterwards to provide a long-term picture of metabolic activity. The data from one of the subjects ended up not being used because the cell company dropped the call. [Ars Technica]