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Genetically engineered mosquitoes pass lethal gene to offspring

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  • Scientists carry out ‘positive’ trial on Cayman Islands
  • New breed of insect could be used to tackle malaria and dengue fever
  • But critics say it could lead to public health problems

Breakthrough or danger? A UK-based research team has found a way of genetically modifying the Aedes aegypti mosquito so they pass on a deadly gene to their offspring

Breakthrough or danger? A UK-based research team has found a way of genetically modifying the Aedes aegypti mosquito so they pass on a deadly gene to their offspring

Serious concerns have been raised over the release of a new breed of disease-fighting mosquito which has been genetically engineered to kill their own offspring.

There are hopes the project could be used to control agricultural pests and tackle deadly insect-borne illnesses such as dengue fever and malaria.

But the research has raised concerns about the possible side-effects on public health and the environment because, once released, the mosquitos cannot be recalled.

A UK-based scientific team revealed there had been positive signs from the first release into the environment of the mosquitoes, which are engineered to pass a lethal gene onto their offspring, killing them before adulthood.

The study team – which includes experts from Imperial College London and the Liverpool School of Tropical Medicine – released batches of modified mosquitoes in an area of the Cayman Islands where the dengue virus-carrying Aedes aegypti mosquito is common.

The study, published in Nature Biotechnology journal, looked at how successfully the lab-reared, genetically modified insects could mate.

About 19,000 mosquitoes engineered in a lab were released over four weeks in 2009 in a 25-acre area on Grand Cayman island.

Based on data from traps, the genetically engineered males accounted for 16per cent of the overall male population in the test zone, and the lethal gene was found in almost 10 percent of larvae.

Those figures suggest the genetically engineered males were about half as successful in mating as wild ones, a rate sufficient to suppress the population.

Disease fighter? The new breed of mosquitoes could be used to tackle killer illnesses like dengue fever and malaria which affect the world's poorest populations

Disease fighter?  The new breed of mosquitoes could be used to tackle killer illnesses like dengue fever and malaria which affect the world’s poorest populations

Luke Alphey, chief scientific officer at Oxitec, the firm which devised the technique, told the BBC: ‘We were really surprised how well they did.

‘For this method, you just need to get a reasonable proportion of the females to mate with GM males – you’ll never get the males as competitive as the wild ones, but they don’t have to be, they just have to be reasonably good.’

HOW MOSQUITOES KILL THEIR OWN CHILDREN

  • The genetic approach used to create the mosquitoes is a system known as tetracycline-controlled transcriptional activation (tTA).
  • The technique is an extension of one successfully used for decades to control or eradicate pests which involves sterilising millions of insects with radiation.
  • But the process has not worked with mosquitoes, partly because the radiation also injures them, making it difficult for them to compete with healthy counterparts for mates.
  • So Oxitec has now created the Aedes aegypti mosquitoes with a gene that will kill them unless they are given the common antibiotic tetracycline.
  • With tetracycline provided in the lab, the mosquitoes can be bred for generations and multiplied.
  • Males are then released into the wild, where tetracycline is not available.
  • They live long enough to mate but their progeny will die before adulthood.

 

Authorities in the Florida Keys hope to carry out an open-air test on the modified insects as early as December after experiencing the region’s first cases of dengue fever in decades.

Dr Alphey said the technique was safe because only males were released as it was only the females that bite people and spread the disease.

But critics say the process is by no means foolproof.

Alfred Handler, a geneticist at the Agriculture Department in Gainesville, Florida, said the mosquitoes can evolve resistance to the lethal gene while being bred for generations in a lab.

Todd Shelly, an entomologist for the Agriculture Department in Hawaii, also said in a commentary published on Sunday by Nature Biotechnology that 3.5per cent of the insects in a lab test survived to adulthood despite presumably carrying the lethal gene.

Also, the sorting of male and female mosquitoes, which is done by hand, can result in up to 0.5per cent of the released insects being female, the commentary said.

If millions of mosquitoes were released, even that small percentage of females could lead to a temporary increase in disease spread, it was reported by the New York Times.

Oxitec and a molecular biologist, Anthony A. James of the University of California, Irvine, say they have developed a solution — a genetic modification that makes female mosquitoes, but not males, unable to fly.

The grounded females cannot mate or bite people, and separating males from females before release would be easier.

The World Health Organisation expects to release guidance on how GM insects should be deployed in developing countries by the end of the year.

 

Via DailyMail

Gene that lights up under green light could help find cure for HIV

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Glowing kittens with resistance to disease have been created by scientists searching for a cure for Aids.

The domestic cats had their DNA modified with a gene that fights off an HIV-like virus and a second one – from a fluorescent jellyfish – that makes their bodies shine green under ultraviolet light.

The purpose of the study was to show how a natural protein that prevents macaque monkeys developing Aids can do the same in cats.

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Way to glow: The eerie looking feline that has been genetically modified with DNA from a fluorescent jellyfish protein

Way to glow: The eerie looking feline that has been genetically modified with DNA from a fluorescent jellyfish protein

Hard to hide: The kitten's fur, claws and whiskers emit an eerie green glow

Hard to hide: The kitten’s fur, claws and whiskers emit an eerie green glow

The two genes are linked and the jellyfish gene is used to track the other one for the protein.

Shining a UV light on the cats produced an eerie green glow, confirming that the protein was being made in their tissues and that the technique had worked.

The genetically modified cats’ creators say the research will speed up the search for vaccines and treatments against HIV, the Aids virus that has claimed more than 30million lives around the world.

With HIV-like viruses also wreaking havoc among felines, from domestic moggies to big cats, the research could improve animal health.

In future, people could buy pets that are resistant to numerous diseases, removing the need for frequent and expensive trips to the vet for vaccination.

Novelty glow-in-the-dark breeds are also a possibility.

Test subject: Under normal lighting the cat's ability to glow remains a secret

Test subject: Under normal lighting the cat’s ability to glow remains a secret

But critics say the technique takes a high toll on animal welfare and that scientists should be reducing the number of animals they experiment on.

The researchers, from the respected Mayo Clinic in the U.S., used harmless viruses to transfer genes into eggs removed from pet cats during routine spaying.

One gene makes a fluorescent protein, the other produces a protein that fights off feline immunodeficiency virus, or FIV, the cat version of HIV. The eggs were then fertilised through IVF and implanted in surrogate mothers.

Sharp thinking: The cat's paws glow too. Scientists say that cats are the best subjects for this kind of research

Sharp thinking: The cat’s paws glow too. Scientists say that cats are the best subjects for this kind of research

Twenty-two attempts led to the birth of five kittens – three of which survived, the journal Nature Methods reports.

Two were healthy but one suffered medical problems, although the researchers do not believe they were linked to the genetic manipulation.

The anti-viral gene was also present and cells taken from the kittens were able to resist infection with FIV better than those from normal cats.

Two of the cats went on to have kittens of their own, all of which carried the new genes.

Via DailyMail

Written by Nokgiir

September 19, 2011 at 3:12 am

Immune System Trained to Kill Cancer

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A year ago, when chemotherapy stopped working against his leukemia, William Ludwig signed up to be the first patient treated in a bold experiment at the University of Pennsylvania. Mr. Ludwig, then 65, a retired corrections officer from Bridgeton, N.J., felt his life draining away and thought he had nothing to lose.

Doctors removed a billion of his T-cells — a type of white blood cell that fights viruses andtumors — and gave them new genes that would program the cells to attack his cancer. Then the altered cells were dripped back into Mr. Ludwig’s veins.

At first, nothing happened. But after 10 days, hell broke loose in his hospital room. He began shaking with chills. His temperature shot up. Hisblood pressure shot down. He became so ill that doctors moved him into intensive care and warned that he might die. His family gathered at the hospital, fearing the worst.

A few weeks later, the fevers were gone. And so was the leukemia.

There was no trace of it anywhere — no leukemic cells in his blood or bone marrow, no more bulging lymph nodes on his CT scan. His doctors calculated that the treatment had killed off two pounds of cancer cells.

A year later, Mr. Ludwig is still in complete remission. Before, there were days when he could barely get out of bed; now, he plays golf and does yard work.

“I have my life back,” he said.

Mr. Ludwig’s doctors have not claimed that he is cured — it is too soon to tell — nor have they declared victory over leukemia on the basis of this experiment, which involved only three patients. The research, they say, has far to go; the treatment is still experimental, not available outside of studies.

But scientists say the treatment that helped Mr. Ludwig, described recently in The New England Journal of Medicine and Science Translational Medicine, may signify a turning point in the long struggle to develop effective gene therapies against cancer. And not just for leukemia patients: other cancers may also be vulnerable to this novel approach — which employs a disabled form of H.I.V.-1, the virus that causes AIDS, to carry cancer-fighting genes into the patients’ T-cells. In essence, the team is using gene therapy to accomplish something that researchers have hoped to do for decades: train a person’s own immune system to kill cancer cells.

Two other patients have undergone the experimental treatment. One had a partial remission: his disease lessened but did not go away completely. Another had a complete remission. All three had had advanced chronic lymphocytic leukemia and had run out of chemotherapy options. Usually, the only hope for a remission in such cases is a bone-marrow transplant, but these patients were not candidates for it.

Dr. Carl June, who led the research and directs translational medicine in the Abramson Cancer Center at the University of Pennsylvania, said that the results stunned even him and his colleagues, Dr. David L. Porter, Bruce Levine and Michael Kalos. They had hoped to see some benefit but had not dared dream of complete, prolonged remissions. Indeed, when Mr. Ludwig began running fevers, the doctors did not realize at first that it was a sign that his T-cells were engaged in a furious battle with his cancer.

Other experts in the field said the results were a major advance.

“It’s great work,” said Dr. Walter J. Urba of the Providence Cancer Center and Earle A. Chiles Research Institute in Portland, Ore. He called the patients’ recoveries remarkable, exciting and significant. “I feel very positive about this new technology. Conceptually, it’s very, very big.”

Dr. Urba said he thought the approach would ultimately be used against other types of cancer as well as leukemia and lymphoma. But he cautioned, “For patients today, we’re not there yet.” And he added the usual scientific caveat: To be considered valid, the results must be repeated in more patients, and by other research teams.

Dr. June called the techniques “a harvest of the information from the molecular biology revolution over the past two decades.”

Hitting a Genetic Jackpot

To make T-cells search out and destroy cancer, researchers must equip them to do several tasks: recognize the cancer, attack it, multiply, and live on inside the patient. A number of research groups have been trying to do this, but the T-cells they engineered could not accomplish all the tasks. As a result, the cells’ ability to fight tumors has generally been temporary.

The University of Pennsylvania team seems to have hit all the targets at once. Inside the patients, the T-cells modified by the researchers multiplied to 1,000 to 10,000 times the number infused, wiped out the cancer and then gradually diminished, leaving a population of “memory” cells that can quickly proliferate again if needed.

The researchers said they were not sure which parts of their strategy made it work — special cell-culturing techniques, the use of H.I.V.-1 to carry new genes into the T-cells, or the particular pieces of DNA that they selected to reprogram the T-cells.

The concept of doctoring T-cells genetically was first developed in the 1980s by Dr. Zelig Eshhar at the Weizmann Institute of Science in Rehovot, Israel. It involves adding gene sequences from different sources to enable the T-cells to produce what researchers call chimeric antigen receptors, or CARs — protein complexes that transform the cells into, in Dr. June’s words, “serial killers.”

 

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Nasa satellite UARS nearing Earth ‘could land anywhere’

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Upper Atmosphere Research Satellite

A five ton, 20-year-old satellite has fallen out of orbit and is expected to crash somewhere on Earth on or around 24 September, according to Nasa.

Nasa says the risk to life from the UARS – Upper Atmosphere Research Satellite – is just 1 in 3,200.

It could land anywhere between 57 degrees north and 57 degrees south of the equator – most of the populated world.

However, most of the satellite will break or burn up before reaching Earth.

Scientists have identified 26 separate pieces that could survive the fall through the earth’s atmosphere, and debris could rain across an area 400-500km (250-310 miles) wide.

Nasa said scientists would only be able to make more accurate predictions about where the satellite might land two hours before it enters the Earth’s atmosphere.

Falling space debris

Rocket propellant tank (Nasa)
  • Hardware re-enters at shallow angles (<1 degree)
  • Some 50 items weighing >1 tonne re-enter a year
  • Major break-up occurs about 80km altitude
  • 10-40% of dry mass on orbit will survive
  • Debris spreads over long, thin “footprints”
  • It can be a hazard to people and property

Re-entry

The 1 in 3,200 risk to public safety is higher than the 1 in 10,000 limit that Nasa aims for.

However, Nasa told reporters that nobody had ever been hurt by objects re-entering from space.

Members of the public are not allowed to keep pieces of the satellite that may fall to Earth, or sell them on eBay, as they remain the property of the US government.

The UARS was launched in 1991 by the Discovery space shuttle, and was decommissioned in 2005.

The latest satellite re-entry is much smaller than Skylab, a satellite that re-entered the earth’s atmosphere in 1979.

It was some 15 times heavier than the UARS, and when it crashed in Western Australia the US government had to pay clean-up costs to the Australian government.

Sputnik 2 crashed on Earth in 1958, travelling from over New York to the Amazon in 10 minutes. It was viewed by many people and left a trail of brightly coloured sparks behind it.

Via BBC

Written by Nokgiir

September 19, 2011 at 2:48 am

Japan’s citizen scientists map radiation, DIY-style

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With the Japanese government only providing spotty information about the radiation leaking from the damaged Fukushima nuclear plant in the early days after the devastating March 11 earthquake and tsunami, a group of tech-minded citizen scientists set out to fill in the “black holes” in the knowledge base.

They did so by crafting their own Geiger counters and handing them out to volunteers in the disaster area to measure the fallout. Months later, they have assembled thousands of radiation readings plotted on maps that they hope will one day be an invaluable resource for researchers studying the impact of the meltdown at the crippled nuclear complex.

Volunteer Toshikatsu Watanabe, left, and Safecast’s Kalin Kozhuharov take radiation measurements in Koriyama, Japan.

The volunteer network of scientists, tech enthusiasts and residents of Japan collectively known as Safecast (an amalgam of “safety” and “broadcast”) sprang to life in the weeks after the devastating 9.0-magnitude earthquake and tsunami struck Japan, cutting off power to the Fukushima Daiichi Nuclear Power Station and knocking out its backup generators. That shut down the plant’s cooling system, triggering meltdowns or partial meltdowns in three of the plant’s four reactors, followed by explosions that released radioactive substances into the air and allowed contaminated water to leak into the ocean.

“For the scientific community, this is a huge chance to further understand what this all means,” said Pieter Franken, co-founder of Safecast and a senior researcher at Keio University in Tokyo, which is collaborating on the project. “Chernobyl was 25 years ago and delivered lots of information. But we’re now in the Internet age, and we have a huge opportunity to do a much better job in measuring it and tracking it.”

Residents in the surrounding areas were understandably alarmed, but in the early days after the disaster, information from the government came in bits and pieces, and was difficult to find.

Franken and Sean Bonner, a Los Angeles-based technology buff involved in numerous online citizen-involved projects, saw an opportunity to use technology to augment the government’s reports and to make the information widely available.

The pair found Uncorked Studios, a Portland, Ore., website development firm, which wanted to map the radiation numbers from all sources “to try to get a better picture of things on a larger scale,” Bonner said.

‘Unknowns’
The initial effort resulted in a map that revealed the dearth of information available: “We realized that there were some massive holes and that the data that was being published was not that specific,” said Bonner. “There would be one reading for an entire city. But we wouldn’t know exactly where in the city that reading was taken.”

With so many “unknowns,” the group decided to buy as many Geiger counters as possible and distribute them to people in the map’s “black holes,” Bonner said. But that wasn’t feasible because the supply of the radiation-measuring devices was limited, he  said.

So Safecast turned to a source they knew well: Hackerspaces, a loose confederation of high-tech tinkerers around the globe.

The TokyoHackerSpace had already drafted a to-do list in the disaster’s aftermath that included radiation monitoring. But with Safecast’s encouragement, the group stepped up its efforts. Members soon figured out how to build basic Geiger counters with Geiger tubes (which measure radiation) purchased through an initial fundraising campaign and modified so they could be attached to vehicles and upload data to the Internet, Christopher Wang, a specialist in sensor networks also known by his hacker nickname of “Akiba,” wrote in an email to msnbc.com.

After meeting Safecast, the hackers decided the best use of the jury-rigged devices would be to drive around taking measurements, allowing one “Geiger counter to cover a huge amount of range,” Wang wrote.

“We put together a custom circuit board that would mount on the outside of a car and had GPS (for timestamp and location data), an input for the Geiger counter, an SD card slot (for data logging), and wireless communication (to send the data inside the car and let the driver know if they are in an area with high radiation),” he said.

Other hackerspaces around the world — such as CRASH space in Los Angeles — soon enlisted in the effort and before long Safecast had the resources to launch an ambitious measuring and mapping effort.

Components of the jury-rigged Geiger counters.

While signing up volunteers, Safecast also developed a training regimen so the recruits would be able to take reliable readings with the instruments and send the data to the group.

Having average citizens involved was crucial, Franken said.

“We want to bring the radiation levels to people’s doorstep, so people can see around their house what is happening,” he said.

Safecast took its first reading on April 16. Today, it has about 50 regular volunteers who collect data from their homes or while driving, build devices or assist in other ways. Those using vehicles equipped with Geiger counters cover an area that Franken estimates to be about 620 miles long by 185 miles wide. To date, they’ve collected 251,000 data points from their drives and fixed reporting stations, and have received about 60,000 more from other sources, including people with their own Geiger counters.

Safecast publishes the data on its website and publishes it to a number of other places so the information can be used by the greatest number of people, Bonner said. It also aggregates radiation data from a number of sources, including the Japanese government.

A Safecast map shows radiation readings from northeastern Japan.

The color-coded maps that Safecast has published don’t always agree with the government’s readings. But Franken said the effort isn’t intended to suggest that the government’s information is bad. The government currently has available a website with the readings of environmental radioactivity level by prefecture.

“We really don’t want to say that the government is wrong,” he said. “And, in fact, in many cases we find that the measurements are fairly much in sync where they are comparable — we have just much more data points and locations measured.”

For example, Safecast’s mapping has revealed some radiation hotspots far from the plant, while other areas closer to it show lower levels. This is due to local weather conditions and air flow, meaning distribution of radioactive materials is not just a matter of proximity, Franken said.

“It’s not so predictable and it really pays to go and map the whole area, and literally find areas that are higher or lower as we go,” he said, noting that in some cases radiation levels can vary by street and even within a home.

“It’s kind of a heavy task because it requires a certain amount of guts to go and do it,” he said of the volunteers, noting he had recently trained a woman and her 12-year-old son in Fukushima City how to measure radiation.

Anxiety
But knowing what the levels are has helped ease some of the anxiety over the radiation exposure, Franken said.

“The measurements may or may not affect people’s decisions but in many cases we see that it more or less gives a sense of confidence that this is what it is and, ‘yeah, I’m going to stay and this is probably going to be manageable,’ or ‘no, I really don’t want to take the risk for my family, I’m going to avoid this.’”

One of the volunteers helping in the effort is Brett Waterman, a 46-year-old Australian who runs an English-language after-school program for children nearly 30 miles from the Fukushima plant, in the city of Iwaki. He has been surveying the radiation levels using a Geiger counter mounted on his car.

“There are many people who have decided that the lack of information implied that there was too much risk so they just decided to leave,” he said.

But through his work, he has learned that the radiation levels were low in the area.

“We can’t see it, but if we map it out, like we are doing street by street, we can sort of start to see it in a sense. We can get a picture of what this radiation stuff is,” he said.

His 13-year-old son is a “significant motivator” for him to take the readings. He noted that though residents don’t yet know what the long-term effects of the radiation will be, the information will be key in the future.

“In 10 years or 20 years’ time, you can’t go back to three months after the event and then find out what the data was like. But if we record it now, and then we continue to record it over the months and years to come, then from a scientific and a community point of view there is a database that can be referenced.”

Some researchers and government agencies welcome Safecast’s endeavor. Andrew Maidment, associate professor of radiology at the Hospital of the University of Pennsylvania, said the efforts were “necessary and helpful,” though he added two “cautionary notes.”

“The first is that the data are only useful, if it is clear (1) how the measurements were performed and (2) exactly where the measurements are performed,” he wrote in an email to msnbc.com. “In general, it is very easy to get erroneous measurements; consistency in following a specific protocol and lots of practice are necessary to do this right. … However, I will say that the data looks consistent since there are repeated measurements and they are spatially correlated. The second problem is that interpretation of the data is hard. Thus, the use of a color code is questionable.”

Japan’s Ministry of Education, Culture, Sports, Science and Technology did not respond to emails and a call seeking comment on the project.

The U.S. Nuclear Regulatory Commission said it was not in a position to comment on the initiative, but public affairs officer Scott Burnell noted in an email: “Speaking very generally, significant training and specialized equipment is required to provide the most accurate surveying and analysis of radioactive materials in the environment.”

Franken said Safecast encouraged dialogue with critics and supporters: “We feel that it is good to have an independent measurement available to people … I think just having more is probably better,” he said.

And Bonner said the initiative has the potential to eventually extend far beyond Japan.

“What all of this did sort of brought to light the fact that this data doesn’t exist in the quantities that it should and is not as readily available as would be helpful,” he said. “So while Japan is the focus at the moment, you know, longer term we sort of are shifting to a global outlook. There is a lot more ground to cover once everything in Japan is wrapped up.”

 

Via MSNBC/Miranda Leitsinger

Fusion Experiment Faces New Hurdles

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The world’s most-ambitious nuclear experiments have escalated at Lawrence Livermore National Laboratory.

Federal researchers there are seeking to fuse some of the lightest atoms in the universe to study — and hopefully harness — the type of energy produced by hydrogen bombs and the sun.

The tests were delayed six months while safety devices were installed to protect workers from radiation at the National Ignition Facility, a stadium-sized laboratory that contains 192 lasers trained on a target the size of a BB. The goal is to generate temperatures of more than 100 million degrees to fuse hydrogen atoms and release nuclear energy.

Scientists describe this process, which they hope to achieve next year, as the creation of a miniature star on earth.

But the $3.5 billion ignition facility, derided by some critics as taxpayer-financed science fiction, is running into new challenges that may further delay and perhaps scuttle its goal.

Among those challenges is the unanticipated presence of particles that clog filters designed to prevent the escape of radioactive material. Officials have proposed bypassing the filters for some experiments and venting radioactive particles directly into the air.

Officials say the radiation risks to people living in the surrounding area and to Lawrence Livermore researchers not involved with the experiments will be negligible. But according to a worst-case scenario outlined in a draft environmental report, an average of one worker involved in the experiments could die every 18 years from cancer caused by radiation exposure.

Tri-Valley CAREs, a watchdog group that monitors Lawrence Livermore, argues that the National Nuclear Security Agency, which financed construction of the facility, should not allow an increase in the amount of radiation produced by the fusion project.

“There is no safe level of exposure,” said Marylia Kelley, the group’s executive director.

The ignition facility was designed to help the United States government monitor the safety of nuclear weapons without having to test them. One of its primary missions is to help improve the United States’ weapons arsenal, but officials also describe the facility as an effort to revolutionize nuclear power.

If researchers can fuse atoms and control the energy that is released, an era of abundant carbon-free power could dawn. The technology would minimize the waste and storage issues faced by fission-based nuclear power plants, which split heavy atoms into smaller ones.

The tipping point for nuclear fusion is “ignition,” the moment when the lasers release the same amount of energy that is required to power them.

But that goal has remained elusive.

“If it was easy, we would have done it 50 years ago,” said Doug Eddy, a senior nuclear security agency operations manager working on the project.

Mr. Eddy said the ignition facility was engaged in a “tuning campaign,” raising the amount of fuel used and the amount of energy generated by the lasers.

“You keep bringing it up a bit more and more and more,” he said. “You don’t want to go big-time straight off the bat.”

Researchers have discovered that more power will be needed for some tests than first thought, Mr. Eddy said. They propose nearly tripling the amount of laser power to 120 megajoules, roughly the equivalent amount of energy produced by 50 pounds of TNT, which will increase radiation levels.

The types of hydrogen that will be fused are called deuterium and tritium. Tritium is radioactive, and fine molecular filters are installed at the facility to prevent it from escaping.

But the tritium is proving difficult to manage. The molecules are so small that other tiny atoms are also captured in the filters. Workers frequently enter the experiment chamber to change the clogged filters.

To solve that problem, officials propose allowing more tritium to accumulate before the filters are removed and sent to Nevada as low-level radioactive waste.

More controversially, the officials have proposed bypassing the filters during some experiments and venting tritium through an exhaust system into the air.

Tritium dissolves in water, persists for decades in the environment and can cause cancer.

“It will bind to DNA, so it gets pretty much everywhere in the body once it’s been absorbed,” said Mark Little, a senior scientist at the National Cancer Institute who has published papers dealing with tritium’s hazards. “With large quantities, damage can be done. As long as the releases are kept within mandatory limits, I would imagine the risks are small.”

Officials at the Department of Energy say the tritium releases at Lawrence Livermore would remain below safety limits set by the Environmental Protection Agency. But Tri-Valley CAREs points to a long list of tritium accidents and airborne releases from Livermore facilities, which have caused radioactive material to accumulate in Livermore’s water, food, honey and wine.

“When tritium gets into the environment and it’s on top of radiation being released from other parts of the laboratory, it potentially increases the dose and potentially increases the risk,” Ms. Kelley said.

And tritium is not her organization’s only concern, she added.

When tritium and deuterium fuse to create helium, a neutron is squeezed out and radiation is released. The neutrons can seep out of the building and rise into the atmosphere, where they cause additional radiation called skyshine to rain back down.

“If it’s high-enough energy, it can scatter and go up to the atmosphere, scatter in the atmosphere and bounce back down,” Mr. Eddy said. “Where it will scatter down is mostly around the site, but there’s no guarantee.”

Officials said that they would determine an area around the Livermore building where radiation might exceed federal safety standards and that Livermore personnel not involved with the research would be evacuated from those areas. Employees will be warned not to enter the area until after the experiment.

Despite several delays, Mr. Eddy said he was confident that ignition would occur next year. But some scientists question whether ignition will ever be possible.

“It’s a tough job, and some of the peer review questioned whether it would work,” said Frank von Hippel, a Princeton University physics professor and former science adviser to President Bill Clinton. “I think there are still skeptics out there.”

 

Via NYTimes

Japan nuclear: Radiation halts water clean-up

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Operators of Japan’s Fukushima nuclear plant have suspended an operation to clean contaminated water hours after it began due to a rapid rise in radiation.

Some 110,000 tonnes of water have built up during efforts to cool reactors hit by the 11 March earthquake and tsunami. The contaminated water, enough to fill 40 Olympic-sized swimming pools, has been at risk of spilling into the sea. The disaster caused meltdown at three of the reactors, and radiation leaks. It is the world’s worst nuclear accident since Chernobyl in Ukraine in 1986. The powerful earthquake and the tsunami it generated are now known to have killed more than 15,280 people, while nearly 8,500 remain unaccounted for.

Radioactive sludge?

A spokesman for the plant operators, the Tokyo Electric Power Company (Tepco), said engineers were trying to find the cause of the jump in radiation levels. “The level of radiation at a machine to absorb caesium has risen faster than our initial projections,” the spokesman said.

He added that until they knew what was causing the rising levels they would not know when the operation would be able to resume.

“But I’d say it’s not something that would take weeks,” he added.

Dealing with the radioactive water is a key step to bringing the crisis at the Fukushima Daiichi plant under control, reports the BBC’s Roland Buerk from Tokyo.

It is the rainy season in Japan and the pools of contaminated water could overflow, adding to radiation already released into the sea, adds our correspondent.

Earlier this week, officials had warned the radioactive pools were in danger of spilling into the sea within a week.

The Fukushima power station went into meltdown after its cooling systems were crippled by March’ s devastating earthquake and tsunami.

The teams at the plant suspect the radiation rise may be linked to sludge flowing into the machinery intended to absorb caesium or the pipes surrounding it. The tsunami destroyed both power and back-up generators at the plant, breaking the cooling systems. The three unstable reactors are supposed to be brought to “a stable and cold shutdown” by January 2012. Despite the setbacks Tepco says it is still on track to meet that deadline.

 

Via BBC