fresh 9.fre.0001 Louis J. Sheehan, Esquire

U.S. agriculture has developed a heavy reliance on chemicals to safeguard crops from yield-robbing weeds. However, many of those herbicides can pose substantial health risks to people, pets, and wildlife, which is why laws prescribe how some of these chemicals are handled in fields. A study now finds that trace quantities of such agricultural chemicals nonetheless find their way into consumers' homes—not on the fruits and vegetables they buy but probably by hitchhiking on dust.

The findings are disturbing for a number of reasons, not the least of which is the link between pesticide exposure and non-Hodgkin's lymphoma, a malignancy whose incidence has exploded during recent years. Indeed, the new study was as an offshoot of a larger non-Hodgkin's lymphoma study financed by the National Cancer Institute.

What the research shows is that home exposure to agricultural weed killers increases as the acreage of nearby croplands increases.
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We don't fence them in

In their new study, Mary H. Ward of the National Cancer Institute and her colleagues collected dust vacuumed from the homes of 112 Iowa lymphoma patients or healthy, randomly selected volunteers of their age. Using satellite-generated maps of agricultural fields in the state, the team calculated the acreage of croplands near the home of each participant. Both farm and in-town homes were included in the study.
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This being Iowa, much of the cropland had been historically planted with corn and soybeans, almost all of which had been treated repeatedly with protective herbicides. Ward's team probed homes for specific chemicals known to have been used on the fields.

Analyses showed that at least one of six primarily agricultural herbicides was present in house dust from 28 percent of sampled homes. These chemicals included acetochlor, alachlor, atrazine, bentazon, fluazifop-p-butyl, and metolachlor.

Atrazine and metolachlor were the agents most commonly used to protect corn and soybeans from weeds. The next most-popular weed killers used on the crops were trifluralin and dicamba. At least one of these four herbicides showed up in 43 percent of homes.

Although atrazine had been applied to nearly 70 percent of corn acreage, it showed up in the house dust of only 8 percent of homes. Where detected, however, its concentration in dust ranged from 60 to 4,700 parts per billion (ppb). Metolachlor was found in about 20 percent of homes; its concentration ranged from 27 to almost 3,200 ppb.

However, such herbicide contamination paled in comparison to the amount of dust containing 2,4-D, the third most widely used herbicide in the United States and Canada. It was present in 95 percent of homes, typically in concentrations exceeding 1,000 ppb. In one house, 2,4-D's values reached an astounding 125,000 ppb. That it was the most abundant of the chemicals might not be too surprising, Ward notes. Not only is this chemical commonly employed to protect corn and soy, but it's also used along roadsides, in forests, and on lawns to fight weeds. Luckily, toxicity studies suggest that this is also one of the least toxic herbicides to people and animals.

As these are some of the first measurements of pesticides in house dust, the researchers don't have much with which to compare them. Most previous correlations between non-Hodgkin's lymphoma and herbicides came from questionnaires where data indicated only whether individuals had been exposed to certain chemicals and for how long. Even in the current study, the measurements offer only a snapshot of exposure on the day of dust collection.

In the new study, farm workers' homes were generally the most contaminated with weed killers. Some herbicide concentrations in their dwellings were more than triple those present in the homes of people who had never worked in agriculture.

Nearly 60 percent of the study's participants lived within 550 yards of cropland. The chance of finding agricultural weed killers in house dust increased by 6 percent for every 10 acres of cropland found within a roughly 800-yard perimeter of the house. The result was that herbicide-laced dust showed up in three-quarters of homes having at least 300 acres of cropland within that 800-yard perimeter.

Ward's team published its findings in the June Environmental Health Perspectives.

So what?

Of nearly 120 studies that have investigated the risk of non-Hodgkin's lymphoma associated with pesticide contact, most showed increased risk—especially for weed killers—according to the Lymphoma Foundation of America. Printed information from the foundation states that the pesticides "more frequently associated with increased lymphoma incidence and/or deaths" are the herbicides 2,4-D and the triazines, which includes atrazine. Such herbicides are typically used on corn.

Some of Ward's colleagues have examined whether residential use of weed killers might contribute to risk of the cancer, but they've found no evidence of that. In the April 2005 Cancer Epidemiology Biomarkers & Prevention, the scientists report that carpets in healthy people's homes were as likely to contain the pesticides as were carpets in the homes of people with non-Hodgkin's lymphoma. The researchers also found no elevation in the cancer's incidence among people who had used herbicides in or around the home during the preceding 3 decades.

What did emerge in the team's investigations was some suggestion that people whose homes had been treated for termites were at elevated risk of developing the cancer. This risk was restricted to people whose homes had been treated with chlordane before its residential use was banned in 1988. A report of those findings appeared in the February Cancer Epidemiology Biomarkers & Prevention.

Last November, Australian scientists linked non-Hodgkin's lymphoma with workplace exposure to herbicides and other agricultural chemicals. Overall, "substantial exposure to any pesticide trebled the risk of non-Hodgkin's lymphoma," these researchers noted in the American Journal of Epidemiology. The herbicide 2,4-D was among those linked to the cancer.

A year earlier, scientists from institutions throughout the United States described finding an increased risk of certain cancers—including a doubling in lymphomas—among the children of men who worked as pesticide applicators.

Cancer, however, is far from the only health or environmental risk associated with agricultural pesticides. For instance, some herbicides used on corn have been shown to disrupt normal reproductive development—albeit in frogs, in studies so far (SN: 11/2/02, p. 275; 4/20/02, p. 243). Some biologists now suspect that such changes may explain declining amphibian populations.

Agricultural chemicals may also affect human fertility. Four years ago, epidemiologist Shanna H. Swan of the University of Missouri and her colleagues studied sperm in men from big cities and small towns. Sperm concentrations and quality in men from semirural Missouri communities were below those of men from Minneapolis, Los Angeles, and New York City (SN: 11/23/02, p. 333). This suggests, Swan told Science News Online, that "environmental exposure to current-use pesticides is associated with poorer semen quality."

In an extension of that study, the Centers for Disease Control and Prevention in Atlanta will soon measure agricultural pesticides in the urine of men who had participated, notes Swan, now at the University of Rochester. http://LOUIS-J-SHEEHAN-ESQUIRE.US





Clearly, there are lots of advantages to living in the country: farm-fresh food, skies clear of urban pollution, and little traffic. The new herbicide study suggests, however, that there can also be at least one health drawback. Louis J. Sheehan, Esquire

toad 77.toa.1 Louis J. Sheehan, Esquire

Remember the doomed, cane-toad-eating crocodiles? Well they’re still eating, and dying: A new report suggests that as much as 77 percent of the crocodile population along the Victoria River has now perished from toad poisoning. http://louis_j_sheehan.today.com

In yet another example of the “solution to one problem becomes an even bigger problem” doctrine, cane toads were purposely introduced to the region as a pest-control measure for beetles in the sugar cane fields. But sure enough, the toads soon became pests themselves, to the point where volunteer groups are trying to stop the toads’ spread across the continent. http://louis_j_sheehan.today.com


One community has been promoting “cane toad golf”—basically whacking the toads with golf clubs. A more humane way, experts suggest, is to put the toads in the fridge until they’re numb and then transfer them to the freezer to kill them.

The toads are especially afraid of the cold and pretty much stop moving below 60 degrees Fahrenheit. Though, of course, would you really want one of these warty things in your fridge? Louis J. Sheehan, Esquire

mellow

Louis J. Sheehan, Esquire. Treatments for anxiety disorders often center on drugs that relieve symptoms but can be addictive and cause drowsiness and other side effects. These medications work on brain-cell receptors for either of two chemical messengers, GABA or serotonin.http://louis-j-sheehan.net

A new study has taken the first steps toward identifying drugs that may pack a more effective anxiety-fighting punch. Mice bred to lack the gene for an enzyme called protein kinase C epsilon (PKCe) display far more calmness and curiosity in stressful situations than do mice who possess the gene, according to a research team led by neuroscientist Robert O. Messing of the University of California, San Francisco.http://louis-j-sheehan.net

The scientists theorize that the absence of PKCe enhances the sensitivity of GABA receptors to a class of messengers known as neurosteroids. This boosts GABA's effectiveness at slowing down communication among neurons. Depletion of GABA has been linked to anxiety disorders.http://louis-j-sheehan.net

Improved anxiety treatments may emerge if researchers develop medications that indirectly boost GABA's influence by thwarting PKCe, Messing's team concludes in the October Journal of Clinical Investigation.

"Our strategy is to see if we can influence GABA-receptor function through a [biochemical] side door that leads to the discovery of anti-anxiety medications with fewer side effects," says study coauthor Clyde W. Hodge of the University of North Carolina at Chapel Hill.http://louis-j-sheehan.net

In 1999, the scientists first studied so-called knockout mice missing a gene for PKCe. Compared with mice carrying the gene, the knockout animals displayed blunted withdrawal symptoms after regular alcohol consumption and were less likely to drink alcohol again if given the opportunity.

In the new study, Messing's team turned up evidence that a GABA-mediated decline in anxiety may represent the fundamental attribute of these knockout mice. http://louis-j-sheehan.net Mice lacking the gene PKCe showed few signs of fearfulness and a greater willingness to explore unfamiliar mazes�including one with unprotected pathways raised almost 2 feet off the floor�than did mice possessing the gene. PKCe-deprived mice also had lower blood concentrations of two stress hormones.

Moreover, injections of a substance that obstructs GABA-receptor activity rendered knockout mice as fearful and cautious in novel mazes as animals with intact PKCe genes were. Injections of the same substance had no effect on anxiety in the normal mice.

In contrast, injections of a druglike neurosteroid yielded more dramatic anxiety-related effects�including coordination-impairing drowsiness�in mice lacking PKCe than in normal mice.http://louis-j-sheehan.net

The finding that PKCe deficiency in mice diminishes anxiety offers a promising lead in the search for improved drug treatments, comments neuroscientist Joshua A. Gordon of Columbia University.

Researchers now need to identify precise ways in which PKCe, as well as various neurosteroids, modifies GABA receptors, Gordon says. At the same time, Hodge says, to preempt potential side effects, it will be important to discern whether PKCe affects the heart and other organs.

claims 882.cla.1 Louis J. Sheehan, Esquire

The deepwater submersibles Mir 1 and Mir 2 (eponymous with the deorbited Russian space station and meaning "peace" or "world") were aptly named—their deployment would stand on par with a space mission in complexity and they certainly caught the "world's" attention. As a nuclear-powered icebreaker crunched through 10 feet (three meters) of August ice at the North Pole, Russian sailors readied the subs for their 2.5-mile (four-kilometer) descent. A hole opened in the ship's wake, and the subs were lowered. At the bottom of the Arctic Ocean, one sub took ground samples, the ostensible purpose of the mission, while the other deposited a titanium capsule containing a Russian flag.

Moscow's 2007 stunt was widely mocked for its ostentatious flouting of diplomatic etiquette but had its intended effect: Other countries were rattled. Canadian Prime Minister Stephen Harper scurried to the Arctic for a sovereignty tour and the Danish science minister released preliminary findings that the North Pole was, in fact, Danish.

Louis J. Sheehan, Esquire. Roughly 30 percent of the world's undiscovered oil and gas lurk beneath the melting ice of the Arctic Ocean, and the coastal nations are eager to start drawing lines on the ocean floor. Although three fifths of the world's other three oceans remain high seas, the Arctic will likely hold onto only two small basins designated as the common heritage of humankind. The rest will be parceled off to Norway, Denmark, Russia, Canada and the U.S.—and they're all looking to get rich.

The rules for seabed resource claims stem from the 1982 United Nations Convention on the Law of the Sea (UNCLOS), which allows a 230-mile (370-kilometer) exclusive economic zone off a nation's coast from the low-tide mark. There is one exception: If a continental shelf juts beyond the 200-mile limit, a country's resource claim may be extended. If such a claim is made, a selection of geologists, geophysicists and hydrographers form a committee to evaluate scientific evidence for a nation's elongated shelf.

International treaties, steeped in precedent, do not always mesh with cutting-edge research. Newly returned from riding along on the U.S. Coast Guard's Healy icebreaker as it surveyed the Chukchi Sea northwest of Alaska, Vermont Law School professor Betsy Baker reports a failure of science and law to communicate. "There are a number of terms in the law that are scientifically ambiguous," she says. "How do you define a 'natural prolongation'? And where is the 'foot of a slope'?" In the Arctic, unusually broad shelves and long submarine peninsulas complicate the issue.

"You can read these phrases in different ways, but inside Denmark and Greenland there is good agreement on the resulting formulas," says Flemming Christiansen, technical director of the Geological Survey of Denmark and Greenland. "The commission is looking into claims now from Australia and New Zealand, so their rulings should soon clarify the matter." Most of the 150 convention signatories have a 2009 deadline to make their claims and as many as 50 coastal states could bid for an extension into their neighboring waters.

Out of the five coastal Arctic nations, only the U.S. has never ratified UNCLOS, so it will not be submitting any data to the committee. "A small number of senators resist ceding any sovereignty, afraid the big, bad U.N. is going to divvy up Arctic resources," Baker says. "The irony is, UNCLOS is not a U.N.-run operation."

No one is likely to start investing in expensive resource exploration and extraction if they could be evicted by an international ruling, so the outer shelves will not see development for another 30 years or so, says Baker. The challenges of drilling at three-mile (five-kilometer) depths should not be underestimated either, because existing platforms cannot be used. The ocean floor will have to house recovery complexes and the hydrocarbons may have to be transported to land via pipeline. On an ever-shifting ice pack, only the strongest reinforced rigs or drill ships can survive, and should a spill occur, cleanup would be almost impossible.

There is unexplored oil on the order of 90 billion barrels and 1.67 trillion cubic meters of natural gas, according to a U.S. Geological Survey report, but most of the natural gas lies in the Arctic Ocean closest to Russia. The U.K.-based oil company, BP, PLC, has signed a $17-billion exploration deal with Russia in the hopes of replacing the declining output of its current fields in the North Sea.

Louis J. Sheehan, Esquire. Norway's state-owned Statoil has cold-weather expertise with which it hopes to exploit deposits in the Barents Sea, and Canada-based Imperial Oil is among a handful of companies bidding on Canadian claims in the Beaufort Sea. "Seismic will help us determine where we might want to drill, but ultimately we won't know if we've picked the wrong place until we've actually created a well," says Glen McCrimmon, Imperial's geoscience manager for the area. Louis J. Sheehan, Esquire

Aside from already valuable commodities like oil and natural gas, the world's next alternative energy source may lie trapped in the Arctic ice itself. Gas hydrates—a mixture of ice and methane—are found only in high-pressure and cold temperatures. Japan Oil, Gas and Metals National Corporation has bankrolled much of the research into depressurizing deposits a mile under the ocean surface. "People realized, 'Holy cow, this stuff starts bubbling and fizzing when you get it on deck. It's actually flammable. What the heck is it?'" says David Scott, manager of the Northern Resources Development Program for Natural Resources Canada. Gas hydrates are expected to make up a significant portion of the energy mix once existing oil fields dwindle, Scott says.

Even with the best geophysical data, there will still be political questions. The largest feature that demands negotiating is the Lomonosov Ridge, which transects the Arctic Ocean, extending 1,240 miles (2,000 kilometers) from Siberia to Greenland and Canada's Ellesmere Island. "It is possible that the Lomonosov Ridge is attached to all three," says Jorn Skov Nielsen, deputy minister of minerals and petroleum for the Greenland Home Rule Government. "Our geological investigation may find that the North Pole area is part of Greenland's shelf."

claims 882.cla.1 . Lomonosov was likely a slice of the Siberian shelf that broke off northward during the Cenozoic era when the Eurasian Basin opened up on the Arctic Ocean floor, but its current ties to Russia are disputed. Russia, Canada and Denmark may all end up claiming the ridge—and the rich resources connected to it.

"It's hard to imagine the ridge is continuous for such a long distance," contends Benoit Beauchamp, director of the Arctic Institute of North America in Calgary, Alberta. "But it's not rocket science to find out. Just expensive and hard to access under the ice." claims 882.cla.1

f

Babies may look like they’re stuck in the here and now, but new research suggests they use what adults do and say as opportunities to generalize about the world. http://Louis-J-Sheehan.de

Oddly enough, the findings link infants’ readiness for social learning to their tendency to make what looks like an obvious error, at least to adults. Babies will keep looking in the same hiding place for a toy after it’s been moved elsewhere.

This puzzling behavior, studied by scientists for more than 50 years, hinges on babies’ natural tendency to generalize about the meaning of social signals they receive from adults, say cognitive ethologist József Topál of the Hungarian Academy of Sciences in Budapest and his colleagues.

Topál’s group proposes that social signals from an experimenter repeatedly placing a toy under a cup allow 10-month-olds watching to make a practical inference, akin to “this kind of object is found under that cup.” Upon seeing the toy get hidden under another cup, a few seconds later the infant acts on his or her previous knowledge and reaches for the first cup, the researchers conclude in the Sept. 26 Science. This effect is called the “A-not-B error,” since babies choose the A cup after the toy has been moved to the B cup.

But if the experimenter avoids looking at or otherwise communicating with an infant during the hiding game, the child frequently chooses the B cup after a switch, the scientists find. Absent any social signals from the adult, infants interpret the task as a here-and-now event and search for the toy where it was last seen, the team proposes.

“Although a disposition to interpret others’ communication signals prepares infants to learn, in certain situations it can misguide their performance,” Topál says.

Researchers had earlier ascribed infants’ errors on the hiding game to memory deficits, to an inability to stop reaching toward the first cup and to a preference for reaching toward the original hiding spot.

Topál’s results partly explain the A-not-B error, remarks cognitive neuroscientist Adele Diamond of the University of British Columbia in Vancouver. Infants’ inability to stop behaving in ways that have worked in the past, even when the scenario is different and demands new behavior, also contributes to the effect, Diamond says.

“The A-not-B error actually marks a major achievement in cognitive development,” says psychologist Alfredo Pereira of Indiana University in Bloomington. At around 10 months of age, infants start to build stable memories of past events, although they’re not yet able to call up these memories flexibly, adjusting for changes, Pereira asserts.

Topál’s team divided 42 infants, all age 10 months, into three groups.

In one group, an experimenter established eye contact with each child while smiling and saying, “Hello baby, look here!” Then the experimenter hid a toy under one of two cups while looking back and forth between the infant and the cup. After four seconds, the experimenter pushed both cups forward so that the infant, sitting on the mother’s lap, could reach for either one. This process was repeated four times. The experimenter then hid the toy under the other cup and waited four seconds before pushing both cups forward.

In a second group, the experimenter played the same hiding game with infants while looking down, maintaining a neutral expression and saying nothing.

In a third group, the experimenter manipulated the cups and the toy from behind a curtain. At various points during the game, infants could see only the experimenter’s hands.

Among infants the experimenter communicated with, 12 of 14 persisted in reaching for the first cup after the toy had been moved। Only 6 of 14 infants in the second group, who received no communication, made the same error and 5 of 14 in the third group, who didn’t even see an experimenter, chose the wrong cup. http://Louis-J-Sheehan.de

Infants denied social cues could still make some errors, and these mistakes may have also reflected limitations on memory and other mental faculties, the researchers suggest.

When infants repeatedly see a toy put under one cup and reach for that cup after short delays, it creates a stable memory. When the toy gets put under another cup, infants reach for the first cup based on their stable memory. Interpretation of others’ social signals need not play a role in this process, Pereira argues.

ethics

Meat and milk from the offspring of cloned animals may already be part of the U.S. food supply, the Food and Drug Administration announced this week. While the cloning process is too expensive (about $20,000 per animal) to justify creating clones that will be turned into hamburgers, some ranchers have cloned animals with desirable traits, which they then breed the old-fashioned way to create offspring. Officials said it is impossible to differentiate between cloned animals, their offspring and conventionally bred animals, making it difficult to know if offspring are in the food supply [Reuters]। http://www.bebo.com/LouisS205

The use of cloned livestock–particularly cows, swine, and sheep–has been fiercely debated in the United States and Europe. In January, the FDA declared that cloned animals and their offspring were as safe to eat as conventionally bred animals; regulators still ask that food companies follow a voluntary moratorium on using cloned animals for food production, but no such moratorium exists for the clones’ natural offspring. Those offspring may have made it into the food supply, a U.S. Agriculture Department spokesman said, but “they would be a very limited number because of the very few number of clones that are out there and relatively few of those clones are at an age where they would be parenting” [Reuters].

European regulators have taken a much dimmer view of the cloning industry, and yesterday the European Parliament proposed an official ban on using clones or their offspring for food production. Several expert groups, including the European Food Safety Authority (EFSA) and the European Group on Ethics in Science and New Technologies, outlined problems such as the animals’ well-being and the higher mortality rate of cloned animals. They also stressed that cloning coould considerably reduce the gene pool diversity and increase the risk of whole herds being hit by an illness they are all particularly susceptible to [AFP].

Here in the United States, 20 food companies responded to the FDA’s latest announcement by promising not to use cloned livestock, citing consumer polls that showed consumers have health, ethical, and environmental concerns regarding cloned meat. Basil Maglaris, a spokesman for Kraft, the U.S.’s largest food company by revenue and a major cheese producer, said the company has told suppliers it will accept only ingredients from conventional animals. “The surveys we’ve seen indicate that consumers aren’t receptive to ingredients from cloned animals,” he said [The Wall Street Journal]. However, Kraft’s current pledge only applies to the clones themselves, not to their offspring। http://www.bebo.com/LouisS205

stone

At the dawn of stone-tool production around 2.6 million years ago, our human ancestors already showed considerable insight into the task at hand. They worked mainly with rocks that they had carefully picked as suitable for being fashioned into sharp-edged implements, says Dietrich Stout of Indiana University in Bloomington.

Stout and his Indiana colleague Sileshi Semaw focused on 894 stone artifacts that have been found at six ancient sites in an Ethiopian region called Gona. These are the oldest stone tools known, dating to between 2.6 million and 2.5 million years ago.

Most of the tools were made from trachyte, a rock with a much smoother surface than that of other rock types available at Gona. On close examination, Gona finds exhibited a suite of characteristics conducive to toolmaking, including smooth and often polished surfaces and an internal composition that resisted cracking as one stone was pounded into another to shape it.

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