by Kristen Minogue "Free-range" chickens are the gold standard for consumers interested in humanely raised livestock. But for most chickens, the wide-open spaces of a free-range poultry farm aren't nearly as idyllic as they sound. The birds often peck at each other's feathers, causing painful scars, bleeding, and even death. Now, researchers have developed a mathematical model that may help farmers stop the pecking before it starts. It's unclear why chickens like to bite the feathers off their neighbors. According to bird-welfare researcher Bas Rodenburg of Wageningen University in the Netherlands, the best explanation is that they've evolved to peck for food in the wild, and this need is not satisfied on the farm. "Instead of pecking at the floor, for instance, they start pecking at each other's feathers," Rodenburg says. Right now, the only way for free-range farmers to prevent the behavior is beak trimming, a euphemism for cutting off the sharp tip of a bird's beak with a hot blade or directing infrared rays into its inner tissue until the tip falls off a few weeks later. To find a better solution, a team of zoologists and engineers studied video recordings of more than 300,000 hens living on free-range farms in the United Kingdom. The researchers applied a mathematical technique called optical flow modeling, which has been used to study traffic patterns and human crowds, to track how the chickens moved in large groups. The process involved analyzing multiple snapshots of the same 50 to 100 hens taken at different times to find patterns of movement that correlate with chicken-on-chicken violence. © 2010 American Association for the Advancement of Science.

Keyword: Aggression
Link ID: 14316 - Posted: 08.03.2010

by Karin Zeitvogel, AFP People who sleep more or fewer than seven hours a day, including naps, are increasing their risk for cardiovascular disease, the leading cause of death in the United States, a study published Sunday shows. Sleeping fewer than five hours a day, including naps, more than doubles the risk of being diagnosed with angina, coronary heart disease, heart attack or stroke, the study conducted by researchers at West Virginia University's (WVU) faculty of medicine and published in the journal Sleep says. And sleeping more than seven hours also increases the risk of cardiovascular disease, it says. Study participants who said they slept nine hours or longer a day were one-and-a-half times more likely than seven-hour sleepers to develop cardiovascular disease, the study found. The most at-risk group was adults under 60 years of age who slept five hours or fewer a night. They increased their risk of developing cardiovascular disease more than threefold compared to people who sleep seven hours. Women who skimped on sleep, getting five hours or fewer a day, including naps, were more than two-and-a-half times as likely to develop cardiovascular disease. Short sleep duration was associated with angina, while both sleeping too little and sleeping too much were associated with heart attack and stroke, the study says. Copyright © 2010 Discovery Communications, LLC.

Keyword: Sleep
Link ID: 14315 - Posted: 08.03.2010

By WALT BOGDANICH When Alain Reyes’s hair suddenly fell out in a freakish band circling his head, he was not the only one worried about his health. His co-workers at a shipping company avoided him, and his boss sent him home, fearing he had a contagious disease. Only later would Mr. Reyes learn what had caused him so much physical and emotional grief: he had received a radiation overdose during a test for a stroke at a hospital in Glendale, Calif. Other patients getting the procedure, called a CT brain perfusion scan, were being overdosed, too — 37 of them just up the freeway at Providence Saint Joseph Medical Center in Burbank, 269 more at the renowned Cedars-Sinai Medical Center in Los Angeles and dozens more at a hospital in Huntsville, Ala. The overdoses, which began to emerge late last summer, set off an investigation by the Food and Drug Administration into why patients tested with this complex yet lightly regulated technology were bombarded with excessive radiation. After 10 months, the agency has yet to provide a final report on what it found. But an examination by The New York Times has found that radiation overdoses were larger and more widespread than previously known, that patients have reported symptoms considerably more serious than losing their hair, and that experts say they may face long-term risks of cancer and brain damage. Copyright 2010 The New York Times Company

Keyword: Brain imaging
Link ID: 14314 - Posted: 08.02.2010

By Laura Sanders As people grow older, sad films seem sadder. In a recent study, people in their sixties felt sadder than people in their twenties did after viewing an emotionally distressing scene from a movie. This heightened emotional response to sorrow may reflect a greater compassion for other people and may strengthen social bonds, researchers propose. The finding is an important contribution to emotion studies because it adds to a growing body of work showing that emotions don’t deteriorate, says Stanford University psychologist Laura Carstensen, who was not involved in the research. “One of the important findings of this is that the emotion system is in no way broken in old age,” she says. To explore how feelings of sadness change with age, researchers led by Robert Levenson of the University of California, Berkeley brought 222 study participants into the laboratory to watch neutral, disgusting or sad movie clips. The volunteers made up three age groups: young people in their twenties, middle-aged people in their forties, and older people in their sixties. Before watching the movies, participants were hooked up to monitors that recorded physiological responses such as blood pressure, heart rate and breathing patterns. Levenson and his team chose two gut-wrenchingly sad scenes to elicit responses: In the first clip, from the movie 21 Grams, a mother is told of the deaths of her two young daughters. The second scene, from The Champ, depicts a young boy watching his father die after a boxing match. © Society for Science & the Public 2000 - 2010

Keyword: Emotions; Development of the Brain
Link ID: 14313 - Posted: 08.02.2010

by Nazlie Latefi People who smoke pot can feel lost in time—for some, it's part of the draw. Now researchers may have figured out one reason why cannabinoids, the psychoactive compounds in marijuana and hashish, make people feel this way; they disrupt the body's internal clock. Sleeping, eating, and other activities are all part of a 24-hour physiological cycle known as the circadian rhythm. This internal clock is controlled by neurons in a region of the brain called the suprachiasmatic nucleus (SCN). The SCN normally uses light to reset the clock. That's what happens when you travel from one time zone to another. But absent any sensory input, SCN neurons will still maintain a circadian rhythm: People and animals kept in total darkness continue to eat and sleep at the usual times. Several years ago, researchers discovered that SCN neurons possess receptors for cannabinoids. In the new study, a team led by Yale University circadian biologist Anthony van den Pol tried to figure out what role these receptors play. The researchers housed 42 mice in total darkness for 2 weeks to synchronize their internal clocks. In this environment the animals cycled through active and inactive phases lasting about 12 hours each. After 2 weeks, the researchers shined a light into some of the cages shortly after the mice had entered their active phase. Because mice are nocturnal, they became active about 2 hours later in the day than did mice not exposed to light, a phenomenon called "phase delay." But mice given brain injections of cannabinoids before light exposure exhibited much less of a phase delay; they became active only 1 hour later than did animals not exposed to light. © 2010 American Association for the Advancement of Science.

Keyword: Drug Abuse; Biological Rhythms
Link ID: 14312 - Posted: 08.02.2010

by Michael Marshall The selective breeding of some domestic dogs has made their brains rotate forwards, and relocated one key component. Michael Valenzuela at the University of New South Wales in Sydney, Australia, and colleagues, used a brain scanner to look at the heads of 11 dogs that had recently been put down, and two live ones. The dogs came from a variety of breeds, which have been bred over thousands of years to have – among other characteristics – snouts of different lengths. They found that dogs with shorter snouts had brains which were rotated forwards by up to 15 degrees. They also found that the olfactory lobe at the front of the brain, which processes the sense of smell, was shunted downwards. "As a dog's head or skull shape becomes flatter – more pug-like – the brain rotates forward and the smell centre of the brain drifts further down to the lowest position in the skull," Valenzuela says. "It's something that hasn't been documented in other species." "This is the first evidence to suggest that selective breeding to meet specific physical characteristics in breed standards has had an impact on brain organisation," says Lisa Collins of the Royal Veterinary College in Hatfield, UK. It might help explain why long-snouted dogs are better at scent work, such as sniffing out drugs, than short-snouted breeds, she says. © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 14311 - Posted: 08.02.2010

By Emma Wilkinson Health reporter, BBC News A combination pill of two drugs used to treat addiction may help people lose weight, say US researchers. The Lancet reports that Naltrexone, commonly used to treat alcoholics and heroin addicts, and the anti-smoking drug bupropion led to greater weight loss than diet and exercise alone. It is thought the treatment may help beat food cravings. However, one UK expert said he would like to see much higher weight loss for the drug to be used in clinics. Professor Nick Finer, an obesity expert from University College London (UCL), said the drug may prove more useful if researchers can better identify who would benefit. In the study, 1,700 overweight and obese adults were all offered a weight-loss programme with diet and exercise advice. Two-thirds were also given the combination treatment (in one of two doses) and a third were given a placebo, or dummy pill, to take twice a day. Only half completed the trial, which lasted a year. Overall those taking the treatment lost an average of 5% to 6% of their weight depending on the dose, compared with 1.3% in the placebo group. The researchers said if only those who completed the trial were included, weight loss was 8% of body weight for those on the anti-addiction drugs. The treatment was not without side effects which included nausea, headaches, constipation, dizziness, vomiting and a dry mouth. (C)BBC

Keyword: Obesity; Drug Abuse
Link ID: 14310 - Posted: 07.31.2010

Janelle Weaver A Canadian research team that induced pain in mice to help develop a 'grimace scale' recently came under fire from a researcher-support organization, which posted an online commentary suggesting that the scientists may not have complied with Canada's animal welfare regulations. But Canadian officials have since determined that the study did follow national rules for the care of laboratory animals. The research team, led by pain geneticist Jeffrey Mogil of McGill University in Montreal, Quebec, videotaped the facial expressions of mice during 14 pain-inducing procedures, such as immersing the tail in hot water, putting a binder clip on tails, cutting the paw, injecting chemicals into the paw or stomach and constricting or damaging nerves during surgery. The researchers coded the intensity of facial expressions and reported their technique this May in the journal Nature Methods1. Two weeks ago, the Principal Investigators Association, a non-profit organization in Naples, Florida, that "communicates and promotes best practices and continuing professional education", posted a discussion-board topic about the study on Lab Animal eAlert, its online subscription newsletter for researchers. The commentary accused the McGill team of causing severe pain to mice that were not anaesthetized, and questioned whether Mogil and his collaborators followed regulations set by the Canadian Council on Animal Care, the national organization that oversees the use of animals in research. Canadian animal-research guidelines preclude or strongly discourage procedures that elicit severe pain "at or above the pain tolerance threshold". © 2010 Nature Publishing Group,

Keyword: Pain & Touch; Animal Rights
Link ID: 14309 - Posted: 07.31.2010

By Katherine Harmon Binge-shoppers and serial daters might perpetually be living at the whim of their latest impulse, and now research is getting to the biological basis of their seemingly random behavior. "Individuals vary widely in their capacity to deliberate on the potential consequences of their choices before they act," note the authors of a new study on the impulsive tendency. "Highly impulsive people frequently make rash, destructive decisions." Impulsivity has long been linked to the neurotransmitter dopamine, which is involved in learning and reward. And a new model helps to illuminate the connection between the two. The work is described in a study published online July 29 in Science. A team of researchers led by Joshua Buckholtz, a PhD candidate in neuroscience at Vanderbilt University, proposed that people who were more impulsive might have less active dopamine receptors in their midbrain but their brains would be more likely to fire off large quantities of the neurotransmitter when stimulated. To verify their hypothesis, the researchers used PET scans to watch the brains of 32 healthy and psychiatrically normal test subjects ages 18 to 35 (who had no history of substance abuse) while they were taking a classic test to measure impulsivity. Before the first testing round, subjects had taken a placebo pill, but before the second, they were given an oral dose of amphetamine, which can stimulate the brain's reward pathways, mobilizing dopamine. © 2010 Scientific American

Keyword: Drug Abuse; Attention
Link ID: 14308 - Posted: 07.31.2010

By Rachel Ehrenberg Not so long ago, Mozart mania swept the nation. A small study found that students who listened to 10 minutes of a Mozart sonata performed better on a paper-folding task than their peers, and suddenly a flourishing industry sprouted. Mozart’s music sang from CDs and videos marketed for children, babies and moms-to-be. The craze reached a crescendo when Georgia’s governor Zell Miller included $105,000 in his state budget to send every child born in a Georgia hospital home with a classical music tape or CD. “No one questions that listening to music at a very early age affects the spatial, temporal reasoning that underlies math and engineering and even chess,” Miller said. Actually, a lot of researchers questioned the link between listening to music and smarts. In the original study, the “Mozart effect” was minor and lasted only minutes. Follow-up studies found the effect specific neither to the composer nor to music. Students listening to Mozart were just more stimulated than those listening to a relaxation tape or silence. And while arousal can improve learning, research suggests, the effects can be fleeting and aren’t limited to music. Assessments of the original report now tend to be dirges: In the May-June issue of Intelligence, researchers from the University of Vienna published a paper titled “Mozart effect–Shmozart effect.” “It’s a short-lived effect and it spawned a huge industry of baby Einstein, baby Mozart CDs, all sorts of stuff,” says Aniruddh Patel of the Neurosciences Institute in San Diego. “But the science behind it is pretty thin.” © Society for Science & the Public 2000 - 2010

Keyword: Hearing; Language
Link ID: 14307 - Posted: 07.31.2010

By Susan Gaidos Anyone who has felt the sting of tears while listening to a bugler play “Taps,” swooned to a love song or cringed with irritation as a neighbor cranked the heavy metal knows that music can exert a powerful emotive effect. And you don’t need a neuroscientist to tell you that manipulating a melody’s pace, tone and intensity can stir the emotions. Composers of symphonies, pop tunes, movie sound tracks and TV ads all know how to tune an audience’s mood along a dial ranging from sad and glum to cheerful and chipper. But neuroscientists might have something to say about how music orchestrates such profound emotional effects on the brain. And understanding the how may offer a hint as to why music affects humans so powerfully. Over the past decade or so, studies have shown that music stimulates numerous regions of the brain all at once, including those responsible for emotion, memory, motor control, timing and language. While the lyrics of a song activate language centers, such as Broca’s area, other parts of the brain may connect the tune to a long-ago association — a first kiss or a road trip down the coast, perhaps. “It’s like the brain is on fire when you’re listening to music,” says Istvan Molnar-Szakacs, a neuroscientist at the University of California, Los Angeles. “In terms of brain imaging, studies have shown listening to music lights up, or activates, more of the brain than any other stimulus we know.” © Society for Science & the Public 2000 - 2010

Keyword: Emotions; Hearing
Link ID: 14306 - Posted: 07.31.2010

By Bruce Bower At scientific meetings, psycho-biologist Colwyn Trevarthen often plays a video of a 5-month-old Swedish girl giving her mother a musical surprise. Blind from birth, the girl reaches for a bottle and laughs appreciatively as her mother launches into a familiar song about feeding blueberries to a bear. As in baby songs everywhere, Trevarthen says, each line of the Swedish tune runs about four seconds and each stanza lasts about 20. In a flash, the girl raises her left arm — an arm she has never seen — and begins conducting her mother’s performance. The baby, named Maria, moves her arm just before many of the song’s lines begin, leading her mother by about one-third of a second. In some cases, Maria synchronizes her hand movements with the rise and fall of her mother’s voice. Mom’s face glows in response to Maria’s playful directions. “Babies are born with a musical readiness that includes a basic sense of timing and rhythm,” declares Trevarthen, of the University of Edinburgh. Scientists have been finding that these chubby-cheeked cherubs heed a musical sense that moves them and grooves them long before they utter a word. Within a day or two after birth, babies recognize the first beat in a sound sequence; neural signs of surprise appear when that initial “downbeat” goes missing. Classical music lights up specific hearing areas in newborns’ right brains. Even more intriguingly, babies enter the world crying in melodic patterns that the little ones have heard in their mothers’ conversations for at least two months while in the womb (SN: 12/5/09, p. 14). © Society for Science & the Public 2000 - 2010

Keyword: Hearing; Development of the Brain
Link ID: 14305 - Posted: 07.31.2010

By THE NEW YORK TIMES Dr. Dodick — I have been getting non-aura migraines since childhood, around the time my menstrual cycle began. I cut out caffeine, chocolate and red wine in my mid-20s but continue to have migraines once a month in conjunction with my cycle. I am curious if taking a birth control pill that limits the number of periods will also lessen the frequency of migraines? Lauren, Austin Dr. David Dodick of the Mayo Clinic responds: Menstruation is a very common and powerful trigger in women who suffer from migraine. There is evidence — and it has certainly been my experience with patients — that in some women, these attacks are also more severe and last longer than those attacks that occur outside the menstrual period. By definition, attacks of migraine that are triggered by menstruation occur within two days prior and three days after the onset of menstrual flow. While the mechanism by which menstruation triggers migraine is not completely clear, experts believe that the precipitous drop in estrogen levels prior to menstruation leads to changes in the excitability of the central nervous system, including the regions of the brain that are involved in migraine. The answer to your question is yes, for some women, there is evidence that taking a combination oral contraceptive pill continuously does reduce the frequency of migraine attacks associated with menstrual periods. However, you should discuss the risks and benefits of this strategy with your primary care physician or gynecologist. Copyright 2010 The New York Times Company

Keyword: Pain & Touch; Hormones & Behavior
Link ID: 14304 - Posted: 07.29.2010

By Jennifer LaRue Huget A number of my apparently sleep-deprived friends and colleagues, upon learning I planned to write about foods that might help people sleep better, have told me they're eager to see what I come up with. I so hate to disappoint them. But it turns out science has yet to find a magical food that can send us right to slumberland. "The bad news for people trying to talk about food and sleep is that . . . generally it's hard to find foods that help with sleep," says Michael Grandner, a sleep researcher at the University of Pennsylvania's Center for Sleep and Respiratory Neurobiology. "The easier question," Grandner says, "is what are the things to avoid?" Though you might expect caffeine to top that list, Grandner's most recent research, published February in the journal Sleep Medicine, found otherwise. Tracking the diets and sleep habits of 459 women enrolled in the federal government's 15-year Women's Health Initiative, he found that fat was the main nutrient (out of dozens tracked) associated with getting less sleep. "The more fat you ate, the less you slept," he says. Women who ate the most fat slept for shorter times and took more naps, a sign that they didn't get enough restful sleep at night. (He believes his findings apply to the broader population, not just older women.) © 2010 The Washington Post Company

Keyword: Sleep; Obesity
Link ID: 14303 - Posted: 07.29.2010

By Tom Wilkinson, Press Association Pigs can feel optimistic and pessimistic according to how they are being treated, scientists revealed today. Experts from Newcastle University's School of Agriculture, Food and Rural Development found they were just as likely as humans to feel the glass was half empty or half full, depending on their living conditions, as hogs kept in piggy luxury were more likely to respond positively to a new experience than those in less stimulating pens. The scientists hoped the research, which shows pigs are capable of feeling complex emotions, will have an impact on animal welfare. Led by Dr Catherine Douglas, the team employed a technique to "ask" pigs if they are feeling optimistic or pessimistic about life as a result of the way in which they live. In an experiment reminiscent of Pavlov's dogs, pigs were taught to associate a note on a glockenspiel with a treat - an apple - and a dog training "clicker" with something mildly unpleasant - in this case rustling a plastic bag. Then they placed half the pigs in an enriched environment - with more space, freedom to roam in straw and play with toys - while the other half were placed in a smaller, boring environment with no straw and only one non-interactive toy. The team then played an ambiguous noise - a squeak - and studied how the pigs responded. ©independent.co.uk

Keyword: Emotions; Evolution
Link ID: 14302 - Posted: 07.29.2010

By Susan Milius WILLIAMSBURG, Va. — Putting a female lemur on birth control turns her normally informative scents to nonsense, researchers report. Doses of Depo-Provera, a common contraceptive for people, shift the odor secretions of female lemurs so dramatically that their scents no longer give clear cues to kinship, identity and genetic quality, says study coauthor Christine Drea of Duke University in Durham, N.C. A female lemur whose hormones are disrupted by contraceptives may have real trouble attracting a compatible mate, Drea said July 26 at the annual meeting of the Animal Behavior Society. As for people, men and women might not think they’re influenced by each others’ scents, but “Oh, we are!” said behavioral biologist Susan Jenks of the Sage Colleges in Troy, N.Y., after Drea’s presentation. If women react to the hormones the way lemurs do, “maybe you don’t want to be on contraceptives when you’re picking your mate.” Also, said behavioral ecologist Jill Mateo of the University of Chicago, “For any zoo that is chemically contracepting animals, this could have big implications.” Drea and her colleagues have identified more than 300 compounds in the scent secretions of female lemurs. “There is a rich communication system,” she said. Glands on the forelimbs, tail and other parts of the body secrete chemical cues that the lemurs rub onto branches or other community bulletin boards, where neighbors sniff out the news. © Society for Science & the Public 2000 - 2010

Keyword: Chemical Senses (Smell & Taste); Hormones & Behavior
Link ID: 14301 - Posted: 07.29.2010

by Shaoni Bhattacharya I HAVE lost myself," cried Auguste Deter to her physician. Deter was trying to write her name, scrawling "Mrs" in a spidery script, only to forget the rest every time. "What are you eating?" the doctor asked Deter on her second day at the hospital for the mentally ill in Frankfurt, Germany, as the confused 51-year-old lunched on cauliflower and pork. "Potatoes," she replied. That was in 1901. When Deter died five years later, an autopsy revealed that her brain was riddled with strange tangles and plaques of a fibrous material containing the remnants of dead brain cells. She became the first described case of a form of dementia now known by the name of her doctor - one Alois Alzheimer. Over a century later, research into Alzheimer's disease still revolves around efforts to understand those mysterious plaques and tangles. Despite decades of work, no effective treatment exists, never mind a cure. The world's population is ageing, so that search is becoming more urgent. Alzheimer's disease is now recognised as the most common form of dementia, with over 25 million people living with the disease worldwide, and that number is expected to pass 100 million by 2050 (see diagram). Yet today, even definitively diagnosing the disease can still only be done at autopsy. The situation is starting to change, however. Thanks to a new imaging technique, the plaques can now be seen in the brains of living people. Not only could this allow early diagnosis, it is helping to overturn the long-standing orthodoxy over the causes of Alzheimer's and paving the way for effective treatments. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 14300 - Posted: 07.29.2010

By Caroline Parkinson Health reporter, BBC News People who stay in education for longer appear to be better able to compensate for the effects of dementia on the brain, a study suggests. A UK and Finnish team found those with more education were as likely to show the signs of dementia in their brains at death as those with less. But they were less likely to have displayed symptoms during their lifetime, the study in Brain said. Experts said scientists now had to find out why the effect occurred. Over the past decade, studies on dementia have consistently shown that the more time you spend in education, the lower the risk of dementia. But studies have been unable to show whether or not education - which is linked to higher socio-economic status and healthier lifestyles - protects the brain against dementia. The researchers in this study examined the brains of 872 people who had been part of three large ageing studies. Before their deaths they had also completed questionnaires about their education. The researchers found that more education makes people better able to cope with changes in the brain associated with dementia. Post-mortems showed the pathology - signs of disease - in the brains of people with and without long educations were at similar levels. But the researchers found those with more education are better able to compensate for the effects of the condition. It also showed that, for each year spent in education, there was an 11% decreased risk of developing dementia. (C)BBC

Keyword: Alzheimers; Learning & Memory
Link ID: 14299 - Posted: 07.27.2010

Daniel Cressey After an epic series of experiments, a group of researchers has observed and reproduced what could be the spontaneous generation of prions — rogue misfolded proteins that have been implicated in the destruction of the central nervous system. These misfolded proteins, the culprits in Creutzfeldt–Jakob disease and scrapie, are highly infectious. Although famously transmitted by the ingestion of infected meats, prions are also thought to arise spontaneously in a tiny fraction of humans and other animals. Such de novo prion generation has previously been achieved with animal cells using a method called 'protein misfolding cyclic amplification' (PMCA), which involves repeated rounds of ultrasound and incubation. Now, a London-based team reports observing prions appearing from healthy mouse brain tissue1. (Human samples have traditionally proved less amenable to PMCA, and the misfolding of prion proteins is believed to occur at a much lower rate in humans than in mice.) "What we were doing was trying to develop a very sensitive assay for prion detection on a metal surface, so we could use that in prion decontamination," says co-author John Collinge, who heads up the Department of Neurodegenerative Disease at University College London. "It took a while before we could convince ourselves this was a real phenomenon." © 2010 Nature Publishing Group

Keyword: Prions
Link ID: 14298 - Posted: 07.27.2010

By Marla Cone, Emily Elert and Environmental Health News In a sweltering summer in New York City back in 1999, Yolanda Baldwin was eight months pregnant with her first child. She lived near a gas station and across the street from an intersection choked with exhaust-spewing cars and buses. Sometimes the air was so thick with pollution that she could see it, breathe it, smell it, even taste it. And she often wondered what it might be doing to her unborn child. Now Baldwin and several hundred other mothers whose sons and daughters have been monitored for a decade have an answer: Before children even take their first breath, common air pollutants breathed by their mothers during pregnancy may reduce their intelligence. A pair of studies involving more than 400 women in two cities has found that 5-year-olds exposed in the womb to above-average levels of polycyclic aromatic hydrocarbons, or PAHs, score lower on IQ tests. The compounds, created by the burning of fossil fuels, are ubiquitous in urban environments. In African American and Dominican communities of New York City, 249 children are being monitored for the effects of environmental contaminants until the age of 11. And across the Atlantic, in Krakow, Poland, another 214 children are participating in a parallel study. The findings in Poland, reported this spring, are strikingly similar to New York City’s: The children whose mothers had above-average exposure to PAHs scored about four points lower on IQ tests than children whose mothers had below-average exposure. © 2010 Scientific American,

Keyword: Development of the Brain; Neurotoxins
Link ID: 14297 - Posted: 07.27.2010