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19 November 2009

Swimming pools may be fueling allergies

Chlorine products can irritate breathing airways, study finds
Swimming in a chlorinated pool may boost the odds that a child susceptible to asthma and allergies will develop these problems, a study indicates.

"These new data clearly show that by irritating the airways of swimmers chlorination products in water and air of swimming pools exert a strong additive effect on the development of asthma and respiratory allergies such as hay fever and allergic rhinitis," Dr. Alfred Bernard, a toxicologist at the Catholic University of Louvain in Brussels, Belgium, noted in an email to Reuters Health.

"The impact of these chemicals on the respiratory health of children and adolescents appears to be much more important — at least by a factor of five — than that associated with secondhand smoke," Bernard noted.

Taken together with his team's prior studies, he added, "There is little doubt that pool chlorine is an important factor implicated in the epidemic of allergic diseases affecting the westernized world."

In the current study, Bernard and colleagues compared the health of 733 adolescents, 13 to 18 years old, who swam in chlorinated outdoor and indoor pools for various amounts of time with that of 114 "control" adolescents who swam mostly in pools sanitized with a concentration of copper and silver.

In children with allergic sensitivities, swimming in chlorinated pools significantly increased the likelihood of asthma and respiratory allergies, the researchers report in the journal Pediatrics.

Among "sensitive" adolescents, the odds for hay fever were between 3.3- and 6.6-fold higher in those who swam in chlorinated pools for greater than 100 hours and the odds of allergic rhinitis were increased 2.2- to 3.5-fold among those who logged more than 1,000 hours of chlorinated pool time.

For example, among children and teens who swam in chlorinated pools for 100-500 lifetime hours, 22 children out of 369 (6.0 percent) had current asthma, compared with those who had spent less than 100 hours (2 of 144, 1.8 percent). The proportions with asthma rose with longer exposure, to 14 out of 221 (6.4 percent) who had been swimming for 500-1,000 hours, and 17 out of 143 (11.9 percent) who swam for more than 1,000 hours.

The risk of asthma and allergy was not influenced by swimming in copper-silver sanitized pools and children without allergic tendencies were not at increased risk of developing allergies.

"The only plausible explanation" for these observations, the researchers argue, is that the chlorine-based toxic chemicals in the water or hovering in the air at the pool surface cause changes in the airway and promote the development of allergic diseases.

"It is probably not by chance," Bernard told Reuters Health, "that countries with the highest prevalence of asthma and respiratory allergies are also those where swimming pools are the most popular."

The current findings, he and colleagues conclude, "reinforce" the need for further study on the issue and to enforce regulations concerning the levels of these chemicals in water and air of swimming pools.

Sugary and Fatty Food Cravings Could Be as Addictive as Illegal Drugs

For Cari Banks, one of the hardest things to say no to is food.
"I could eat half a pack of Oreos and milk and consider it nothing," she said. "I would eat it, pretty much without thinking."

But new research shows Banks' sweet tooth could actually be more like substance abuse.

Dr. Joe McClernon at Duke University studies the brains of people who are addicted to drugs, such as the nicotine in cigarettes. He says that for many obese people, junk food can trigger the same response in the brain.

"You can see activation when smokers are looking at pictures of people smoking, and the same thing when overweight individuals look at food cues," said McClernon, an associate professor in the Department of Psychiatry and Behavioral Sciences at Duke University Medical Center and director of the Health Behavior Neuroscience Research Program. "We see activation in areas involved in visual attention.

"We also see activation in both cases in a region called the striatum," McClernon added. "It's the part of your brain that tells you whether something is something you want to go after, or if it's something you want to avoid. But it's also the part of the brain that's involved in learning habits."
A new study by researchers at the Scripps Research Institute in Florida found similar results in rats. Pleasure centers in the brains of those fed high-fat, high-calorie food became less responsive over time -- a signal that the rats were becoming addicted. The rats started to eat more and more. They even went for the junk food when they had to endure an electric shock to get it.

"Your brain reacts almost identically to [that of] a cocaine addict looking at cocaine," said Dr. Louis J. Aronne, a clinical professor at Weill Cornell Medical School and former president of The Obesity Society. "And the interesting thing is that someone who is obese has even more similarity to the cocaine addict. ... In many ways, they can be addicted to junk food."

16 November 2009

Wireless Phones Can Affect The Brain, Swedish Study Suggests

A study at Örebro University in Sweden indicates that mobile phones and other cordless telephones have a biological effect on the brain. It is still too early to say if any health risks are involved, but medical researcher Fredrik Söderqvist recommends caution in the use of these phones, above all among children and adolescents. Few children who regularly use mobile phones use a headset often or always, even though the Swedish Radiation Safety Authority recommends this.

"Children may be more sensitive than adults to radiation from wireless phones," says Fredrik Söderqvist, who is presenting his research findings in a new doctoral thesis at Örebro University.

On the one hand, he examined the use of wireless telephones among children and adolescents, on the other hand, whether adolescents themselves perceive any health problems that might be related to this use.

He then went on to study blood samples from adults, looking at two so-called biomarkers to see whether wireless phone use has a biological effect on the brain. One of these studies focused on a protein that exists in the so-called blood-cerebrospinal-fluid barrier, which is part of the brain's protection against outside influences. The study revealed an association between use of wireless telephony and increased content of the protein transthyretin in the blood.

Fredrik Söderqvist stresses that the increase as such does not have to be a cause of concern, but since it indicates that the brain is in fact affected by microwaves from wireless telephones, there may be other -- as yet unknown -- effects that may impact our health.

"We should all follow the recommendations of the Radiation Safety Authority when it comes to using headsets and avoiding mobile phone use when the coverage is poor."

Self-perceived health problems

The study also shows that users themselves experience health problems that may be caused by wireless telephones. Children and adolescents who regularly use wireless telephones more often reported various health symptoms and graded their well-being lower than those who do not use them regularly. According to Fredrik Söderqvist, it is not possible to draw any conclusions about what is cause and effect on the basis of this study, but he feels that it is urgent to examine this association more closely.

"The connection was strongest regarding headaches, asthmatic complaints, and impaired concentration. But more research is needed to exclude the effects of other factors and sources of error, even though it is difficult to see how this connection could be fully explained by such factors."

Impact may be felt in the future

Today nearly all children from the age of 7 have access to a wireless telephone, but usage takes off only around the age of 12, and more than 80 percent of all 19-year-olds use mobile phones regularly. At the same time, the study shows that fewer than two percent of the children and adolescents use a headset often or always.

"This is worrisome, since the possible health effects from long-term exposure to microwaves have not been clarified, especially among children and adolescents. The threshold values in place today protect us from warming, a so-called thermal effect. But if there are mechanisms that are independent of warming, it is not certain that today's thresholds provide protection. And it may be that these are effects that will not be perceived until later on in the future," says Fredrik Söerqvist.