Probing hydrogen under extreme conditions

How hydrogen--the most abundant element in the cosmos--responds to extremes of pressure and temperature is one of the major challenges in modern physical science.

Moreover, knowledge gleaned from experiments using hydrogen as a testing ground on the nature of chemical bonding can fundamentally expand our understanding of matter.

New work from Carnegie scientists has enabled researchers to examine hydrogen under pressures never before possible. Their work is published online in Physical Review Letters.

To explore hydrogen in this new domain, the scientists developed new techniques to contain hydrogen at pressures of nearly 3 million times normal atmospheric pressure (300 Gigapascals) and to probe its bonding and electronic properties with infrared radiation. They used a facility that Carnegie manages and operates at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory in partnership with NSLS.

Observing hydrogen's behavior under very high pressures has been a great challenge for researchers, because it is in a gas state under normal conditions. It is known that it has three solid molecular phases. But the structures and properties of highest-pressure phases are unknown.

For example, a transition to a phase that occurs at about 1.5 million times atmospheric pressure (150 Gigapascals) and at low temperatures has been of particular interest. But there have been technological hurdles in examining hydrogen at much higher pressures using static compression techniques.

It has been speculated that under at high pressures, hydrogen transforms to a metal, which means it conducts electricity. It could even become a superconductor or a superfluid that never freezes--a completely new and exotic state of matter.

EU Legislation: Millions of animals spared from chemical safety tests

Tens of millions of animals will be saved from use in chemical safety tests over the next eight years after Europe’s chemical regulator gave the go-ahead to a new streamlined study to assess the safety of substances.

European Union (EU) legislation requires companies to test the safety of the chemicals they produce in two generations of animals to assess the effects on their reproductive systems.

Toxicologists were concerned that the testing requirement would mean up to 54 million animals would be used in chemical safety studies to meet the requirements of REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) legislation introduced in 2007 (see Chemical-safety costs uncertain).

A proposed new test would allow just one generation of animals to be used, with additional tests on a second generation required only if the first round raised concerns.

The regulator, the European Chemical Agency (ECHA), based in Helsinki, had threatened to reject the test saying that there is not yet enough evidence to rely on one-generation testing (see Streamlined chemical tests rebuffed).

But on 15 February, ECHA announced it has now changed its mind in favour of Extended One-Generation Reproductive Toxicity Study (EOGRTS).

The agency says that the streamlined test will “under certain conditions” provide sufficient safety information to replace the two-generation reproductive toxicity study. It says it has already received around 230 proposals from companies to carry out the new test.

The move comes after Nature revealed that chemical companies were not providing the safety data on reproductive and developmental toxicity REACH requires of them. Nature also found that very few companies were proposing to carry out alternative non-animal tests, causing further concern that REACH would boost the number of animals used in toxicity testing.

Toxicologists say that allowing the streamlined test, which is quicker and cheaper to conduct, will encourage more companies to test their products.

Learning Difficulties: Exposure to Pesticides in Womb

Babies exposed to high levels of pesticides while in the womb may suffer from learning problems, a new study suggests.

The study focused on a chemical called permethrin, one of the pyrethroid pesticides, commonly used in agriculture and to kill termites, fleas and household bugs, says lead author Megan Horton of the Columbia Center for Children's Environmental Health. 

Most of the pregnant women in this New York-based study were exposed by spraying for cockroaches.

Permethrin — among the most commonly detected pesticides in homes — is being used more often today as older organophosphorous pesticides are phased out because of concerns that they harm brain development, says Horton, whose study is being published today in Pediatrics.

Researchers measured 348 pregnant women's exposures by asking them to wear backpack air monitors, Horton says. Researchers followed the women and their children for three years.

Children exposed to the highest pesticide levels before birth were three times as likely to have a mental delay compared to children with lower levels, the study says. 

Children with the highest prenatal exposures also scored about 4 points lower on an intelligence test, the Bayley Mental Developmental Index. That test has a mean score of 100, with most people's scores falling within 15 points of that range.

That's about the same intelligence loss caused by lead, says Philip Landrigan, a pediatrics professor and environmental health expert at New York's Mount Sinai School of Medicine.

Pyrethroid pesticides kill bugs by "being toxic to the developing brain," Landrigan says. The results are "very believable and should be taken seriously," Landrigan says.

Because the study is the first to link permethrin with brain damage, researchers need to conduct additional studies before concluding that the pesticide really harms the brain, says Mary Fox, an assistant professor at John Hopkins' Bloomberg School of Public Health.

Even without definitive data, however, Fox says it makes sense for pregnant women to reduce their exposure to bug sprays and other pesticides.

To control bugs, for example, she suggests fixing water leaks, keeping food tightly covered and, if necessary, spraying outside instead of inside the home.

Russian Ex-navy chief denies dumping nuclear waste in Baltic Sea

Ex-navy chief denies Russia dumped nuclear waste in Baltic Sea

Picture shows the Russian Navy's carrier Admiral Kuznetsov

The former commander of the Russian navy's Baltic fleet on Friday denied Swedish media reports that Russia dumped radioactive and chemical waste into Swedish waters in the Baltic Sea in the early 1990s.

"This is complete nonsense and a clear provocation, propagated at an international level," Admiral Vladimir Yegorov, who commanded the Baltic fleet from 1991 to 2000, told the Interfax news agency.

Swedish Prime Minister Fredrik Reinfeldt on Thursday called for the previous governments to explain a television report that Russia dumped chemical weapons and radioactive waste off the shores of a Swedish island in the Baltic Sea.

According to the television report on the SVT network on Wednesday, the waste dumped in Swedish waters between 1991 and 1994 came from the giant Karosta naval base in the Latvian port city of Liepaja.

"The naval forces that were pulling out of the Liepaja naval base in Latvia in the early 1990s did not have chemical weapons, radioactive materials and waste," Yegorov insisted.

He added that the Russian naval forces were monitored by Latvia as they pulled out of the port and that the naval command acted "strictly within the framework of Russian and Latvian agreements."

A summit of heads of state of countries bordering the Baltic Sea was to take place in Helsinki Wednesday to try to solve the problems of one of the world's most polluted seas.

Russian Prime Minister Vladimir Putin was due to attend.

Suzaku Spies Treasure Trove Of Intergalactic Metal

Suzaku Spies Treasure Trove Of Intergalactic Metal

Recently astronomers used the Suzaku orbiting X-ray observatory, operated jointly by NASA and the Japanese space agency, to discover the largest known reservoir of rare metals in the universe.

Suzaku detected the elements chromium and manganese while observing the central region of the Perseus galaxy cluster. The metallic atoms are part of the hot gas, or "intergalactic medium," that lies between galaxies.

"This is the first detection of chromium and manganese from a cluster," says Takayuki Tamura, an astrophysicist at the Japan Aerospace Exploration Agency who led the Perseus study. "Previously, these metals were detected only from stars in the Milky Way or from other galaxies. This is the first detection in intergalactic space."

The cluster gas is extremely hot, so it emits X-ray energy. Suzaku's instruments split the X-ray energy into its component wavelengths, or spectrum. The spectrum is a chemical fingerprint of the types and amounts of different elements in the gas.