OZONE DEFENSE 

Earth's ozone layer has suffered unprecedented damage above the Arctic this winter, due to a combination of ozone-depleting chemicals and a cold snap in the stratosphere, the U.N. World Meteorological Organization said Tuesday. Roughly 40 percent of the region's stratospheric ozone had been destroyed by the end of March, according to the WMO, compared with a previous record of 30 percent in 2005.

The ozone layer protects humans and other life forms from ultraviolet rays, but it's made of a gas that can be broken down by industrial chemicals, such as chlorofluorocarbons (CFCs). Many of those chemicals were phased out by the 1987 Montreal Protocol, but because they often have long atmospheric lifetimes, it will take decades for them to fall back to pre-1980 levels, as decreed by the Montreal Protocol. In the meantime, they drift around the sky, combining with other factors — such as this winter's severely cold stratosphere — to wear down the ozone layer. That usually happens over colder Antarctica, but as Nature.com reports today, the Arctic may now have experienced its first-ever full-fledged ozone hole. "It's a fair question to ask if there's any difference left between seasonal ozone depletion in the Arctic and in Antarctica," one ozone researcher says. "It's unprecedented, but not totally unexpected," adds the WMO's Geir Braathen.

The Arctic was actually quite warm on the ground this winter, thanks to a strong negative phase of the "Arctic Oscillation," which pushed Arctic weather (including lots of snow) south into the U.S. and Europe. But the Arctic's upper atmosphere was much colder, creating near-Antarctic conditions that let ozone depletion reach historic extremes. "The 2011 ozone loss shows that we have to remain vigilant and keep a close eye on the situation in the Arctic in the coming years," WMO secretary-general Michel Jarraud tells the BBC. U.N. officials predict the subpolar ozone layer will recover to its pre-1980 state sometime between 2030 and 2040, the AP reports.

(Sources: Associated Press, BBC News, Nature)

HONEY TRAP 

Honeybees are capable of detecting pesticides in the pollen they carry back to their hives, a leading U.S. bee expert revealed Monday, and they even try to isolate the toxins away from other bees. They do this by "entombing" the contaminated pollen in honeycomb cells that are sealed with wax, making sure it can't be used for food, said Jeffrey Pettis, head of the USDA's Bee Research Laboratory.

"This is a novel finding, and very striking," Pettis tells the Guardian. "The implication is that the bees are ... recognizing that something is wrong with the pollen and encapsulating it. Bees would not normally seal off pollen." But despite their efforts, this containment strategy doesn't seem to be working — entombing behavior has been observed in many hives that end up dying off, Pettis points out. "The presence of entombing is the biggest single predictor of colony loss," he says. "It's a defense mechanism that has failed." The colonies were likely already in dire straits, he explains, and their downfall may be linked to a variety of factors in addition to pesticides.

Pettis has also shown that bees infected with small doses of imidacloprid, the top-selling neonicotinoid pesticide sold by agribusiness giant Bayer, are more vulnerable to infection by parasites. And the bees almost seem aware that such pesticides may weaken their immune systems, believed to be a major factor in "colony collapse disorder." But while global focus in the fight against CCD has been shifting toward systemic pesticides — especially neonicotinoids — Pettis tells the Independent that pesticides aren't the entire problem. "I think there's more of what I call the 3-P principle — poor nutrition, pesticides and pathogens," he says. "Those three things are interacting greatly. ... You get three of them lined up and surely you'll have bees in poor health. Even the combination of any two could be problematic."

(Sources: Guardian, Independent)

IN HOT WATER 

Some 60,000 tons of radioactive water is believed to have flooded reactor basements and underground trenches outside Japan's crisis-stricken Fukushima Daiichi nuclear plant, the Kyodo News agency reports. Tokyo Electric Power Co., which runs the plant, aims to remove the water and keep it in various storage tanks, U.S. Navy barges and even an artificial island called a "megafloat." But to make room for it, TEPCO will first continue dumping 11,500 tons of low-level tainted water into the Pacific Ocean — a move that government officials describe as inevitable but generally safe.

Yet the dumping has still raised plenty of alarms, and not just in Japan: South Korea has asked the Japanese government for more information, saying it's "natural" for its citizens to be concerned about the discharges, even though they're on the coast facing away from Korea. Officials with Japan's Nuclear and Industrial Safety Agency tried to calm fears Tuesday, apologizing for having raised them in the first place. "We regret having caused concern to other countries because of the discharge of the radioactive water," said NISA deputy director-general Hidehiko Nishiyama, adding that "we will try to avoid further dumping of contaminated water as much as possible." There were signs that radiation has begun to affect sea life, though — a young sand eel caught off the coast of Ibaraki Prefecture has showed levels of radioactive cesium above the maximum allowable limit, Kyodo News reports. It was the first time such levels have been found in seafood since the crisis began last month.

Many experts insist the radiation releases are negligible, though, such as Georgetown University Medical Center's Timothy Jorgensen. "To put this in perspective, the Pacific Ocean holds about 300 trillion swimming pools full of water, and they are going to release about five swimming pools full," he tells CNN. "So hopefully the churning of the ocean and the currents will quickly disperse this so that it gets to very dilute concentrations relatively quickly." Workers trying to prevent more radioactive water from leaking into the ocean made some fleeting progress Tuesday, Dow Jones reports — an injection of "liquid glass," or sodium silicate, temporarily slowed the flow from a damaged pipe, but later failed.

(Sources: Kyodo News, Dow Jones, United Press International, CNN)

DAIRY DOUBLE 

Researchers in China have genetically engineered cows to produce human milk proteins, raising the prospect of one day breeding cattle that could replace the need for infant formula, PhysOrg reports. Humans have been drinking cows' milk for millennia, but it's still not easily digested and absorbed by human infants, making it an unsuitable nursing substitute. For mothers who can't breastfeed, infant formula is therefore the only option — but it can't fully meet an infant's nutritional needs either. Human milk contains a variety of distinctive proteins as well as human lysozome, which is key to fending off bacteria and boosting a baby's immune system.

To address this problem, Ning Li of the China Agricultural University and his colleagues introduced human lysozome and other human proteins into the embryos of Holstein cattle, which they then placed into surrogate cows. When these cows began lactating, their milk contained human lysozome and other human proteins, such as lactoferrin and lactalbumin, which also help fortify the body's immune system during development. The researchers then used a purification process to raise the fat content and milk solids, and to make the milk taste more like actual human breast milk. One day, they say, this genetically modified cow's milk could be available in grocery stores.

While that could be good news for infants who are spared baby formula, it has raised the hackles of those who distrust cloning and genetic modification, PhysOrg notes. (The researchers used cloning technology to insert the human proteins into the cows.) They worry about the potential risk of exposing sensitive infants to this genetically modified milk, as well as about the welfare of the cows themselves. In one of the study's experiments, for example, 10 of the 42 calves died shortly after birth and six others died within a few months.

(Sources: PhysOrg, LiveScience)

THIS DAY IN HISTORY

Indonesian volcano kills up to 100,000 people, the Great Pacific Garbage Patch is discovered, and more.

Russell McLendon

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Photo (cloudy Arctic sky): NASA

Photo (honeybee and hive): NASA Earth Observatory

Photo (worker at Fukushima Daiichi plant on April 2): ZUMA Press

Photo (cow, milk and cheese): ZUMA Press

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