Thursday, September 17, 2009
THURSDAY, Sept. 17 (Livemedinfo News) - Children with blood lead levels well below those considered safe are still at risk for problems with thinker and emotional development, British researchers report.
Currently, the maximum safe blood level of lead is 10 micrograms per deciliter (10 mcg/dl), which was set by the U.S. Centers for Disease Control and Prevention in 1991. However, even this level appears to be too high, professional say.
"This study confirms what we have been considering in recent studies, that the current CDC level of concern here in the United States of 10 [mcg/dl] is not sufficiently protective," said Kim Dietrich, a professor of environmental health at the University of Cincinnati.
This study clearly shows that blood level concentration between 5 mcg/dl and 10 mcg/dl are associated with poorer educational presentation and antisocial behavior, Dietrich said.
Dietrich noted that, in his own studies, he found children exposed to low levels of lead were also prone to criminal action as adults.
The British report is published in the Sept. 17 online edition of the records of Disease in Childhood.
For the study, researchers from the University of Bristol's Center for Child and Adolescent Health, led by Dr. Alan Emond, took blood samples from 582 2-year-olds. The children were participants in the Avon Longitudinal Study of Parents and Children.
When the children were 7 to 8 years old, Emond's team assessed their school performance. Among the 488 children for whom complete data was obtainable, the researchers found a link between blood lead levels at age 2 and academic performance and activities at ages 7 and 8.
In fact, the higher the lead levels at 2, the poorer the later reading, writing and spelling grades, and the greater the chances of disruptive behavior, the researchers found.
Lead levels up to 5 mcg/dl had no obvious effect on intellectual capacity or behavior, but lead levels between 5 mcg/dl and 10 mcg/dl were tied to 49 percent lower reading scores on consistent tests and 51 percent lower writing scores, Emond's group found.
Moreover, children whose lead levels were higher than 10 mcg/dl were about three times more likely to display antisocial performance and hyperactivity, compared with children whose blood lead levels were between 0 mcg/dl and 2 mcg/dl.
Emond's team noted that effects of lead disclosure are worse when children are very young, because lead is easily absorbed and young tissues are particularly weak to damage. Once lead enters the body, it is stored in the bones and can stay there for up to 30 years, the team noted.
The World Health Organization estimation that half of all children under 5 living in cities and towns have blood lead levels above 10 mcg/dl, Emond's group pointed out. Based on their data, the researchers argue that the current threshold of 10 mcg/dl should be lowered to 5 mcg/dl.
"Lead poisoning is a continuing risk, and should be considered in children presenting with behavioral or educational difficulties," the researchers wrote. "Early childhood exposure to lead affects later educational achievement and behavior, even at low blood levels, and the level of concern should be lowered to 5 [mcg/dl]," they concluded.
While exposure to lead in the United States has dropped significantly with the proscription of lead in gasoline and lead-based paint, it still remains a big problem, Dietrich said.
In the United States, lead exposure continues to come from lead-based paint, Dietrich said. "This is still a huge problem," he said. The problem is mainly acute in inner cities among people living in housing built before 1960, he noted.
Lead from paint can be found in dust in the home and in the soil approximately the home, Dietrich said. "This is the result of years of sloughing off of exterior lead paint," he said. "It's still a big problem, and we haven't begun to attack that in any meaningful way."
Lead exposure also comes from toys coated with lead paint, mainly toys from China and India, Dietrich added.
Dietrich agreed that the CDC should lower the amount of blood lead levels deemed safe. "I strongly believe the CDC should reduce the present level of concern," he said. "It's time to get real about this. 10 [mcg/dl] cannot be justified any longer on the basis of the empirical data."
Another expert, Kim Cecil, a professor of radiology, pediatrics and neuroscience at the University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, said that "findings reported in this study suggest we need to do more to protect children in their daily environments."
The science is becoming clearer that lead is harming the brain, despite the historically low levels in Western countries, Cecil said.
"From a public health viewpoint, lowering the level of concern would aid in improving cognitive and behavioral outcomes," she said. "Blood lead screening is necessary for identifying children at risk of permanent brain injury."
Currently, the maximum safe blood level of lead is 10 micrograms per deciliter (10 mcg/dl), which was set by the U.S. Centers for Disease Control and Prevention in 1991. However, even this level appears to be too high, professional say.
"This study confirms what we have been considering in recent studies, that the current CDC level of concern here in the United States of 10 [mcg/dl] is not sufficiently protective," said Kim Dietrich, a professor of environmental health at the University of Cincinnati.
This study clearly shows that blood level concentration between 5 mcg/dl and 10 mcg/dl are associated with poorer educational presentation and antisocial behavior, Dietrich said.
Dietrich noted that, in his own studies, he found children exposed to low levels of lead were also prone to criminal action as adults.
The British report is published in the Sept. 17 online edition of the records of Disease in Childhood.
For the study, researchers from the University of Bristol's Center for Child and Adolescent Health, led by Dr. Alan Emond, took blood samples from 582 2-year-olds. The children were participants in the Avon Longitudinal Study of Parents and Children.
When the children were 7 to 8 years old, Emond's team assessed their school performance. Among the 488 children for whom complete data was obtainable, the researchers found a link between blood lead levels at age 2 and academic performance and activities at ages 7 and 8.
In fact, the higher the lead levels at 2, the poorer the later reading, writing and spelling grades, and the greater the chances of disruptive behavior, the researchers found.
Lead levels up to 5 mcg/dl had no obvious effect on intellectual capacity or behavior, but lead levels between 5 mcg/dl and 10 mcg/dl were tied to 49 percent lower reading scores on consistent tests and 51 percent lower writing scores, Emond's group found.
Moreover, children whose lead levels were higher than 10 mcg/dl were about three times more likely to display antisocial performance and hyperactivity, compared with children whose blood lead levels were between 0 mcg/dl and 2 mcg/dl.
Emond's team noted that effects of lead disclosure are worse when children are very young, because lead is easily absorbed and young tissues are particularly weak to damage. Once lead enters the body, it is stored in the bones and can stay there for up to 30 years, the team noted.
The World Health Organization estimation that half of all children under 5 living in cities and towns have blood lead levels above 10 mcg/dl, Emond's group pointed out. Based on their data, the researchers argue that the current threshold of 10 mcg/dl should be lowered to 5 mcg/dl.
"Lead poisoning is a continuing risk, and should be considered in children presenting with behavioral or educational difficulties," the researchers wrote. "Early childhood exposure to lead affects later educational achievement and behavior, even at low blood levels, and the level of concern should be lowered to 5 [mcg/dl]," they concluded.
While exposure to lead in the United States has dropped significantly with the proscription of lead in gasoline and lead-based paint, it still remains a big problem, Dietrich said.
In the United States, lead exposure continues to come from lead-based paint, Dietrich said. "This is still a huge problem," he said. The problem is mainly acute in inner cities among people living in housing built before 1960, he noted.
Lead from paint can be found in dust in the home and in the soil approximately the home, Dietrich said. "This is the result of years of sloughing off of exterior lead paint," he said. "It's still a big problem, and we haven't begun to attack that in any meaningful way."
Lead exposure also comes from toys coated with lead paint, mainly toys from China and India, Dietrich added.
Dietrich agreed that the CDC should lower the amount of blood lead levels deemed safe. "I strongly believe the CDC should reduce the present level of concern," he said. "It's time to get real about this. 10 [mcg/dl] cannot be justified any longer on the basis of the empirical data."
Another expert, Kim Cecil, a professor of radiology, pediatrics and neuroscience at the University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, said that "findings reported in this study suggest we need to do more to protect children in their daily environments."
The science is becoming clearer that lead is harming the brain, despite the historically low levels in Western countries, Cecil said.
"From a public health viewpoint, lowering the level of concern would aid in improving cognitive and behavioral outcomes," she said. "Blood lead screening is necessary for identifying children at risk of permanent brain injury."
Labels: Lead paint
Wednesday, September 16, 2009
WEDNESDAY, Sept. 16 (HealthDay News) -- Older adults who get habitual exercise may live longer and be at lower risk for physical disabilities, according to an Israeli study.
The research included almost 1,900 people born in 1920 and 1921 who were assessed at ages 70, 78 and 85. Those who did less than four hours of physical movement per week were considered sedentary, while those who exercised about four hours a week, did vigorous activities such as swimming or jogging at least twice a week, or those who got regular physical activity (such as walking at least an hour a day) were measured physically active.
The researchers found that 53.4 percent of participant were physically active at age 70, 76.9 percent at age 77, and 64 percent at age 85. Compared to those who were sedentary, physically active people were 12 percent less likely to die between ages 70 and 78, 15 percent less likely to die between ages 78 and 85, and 17 percent less likely to die between ages 85 and 88.
Physically active participants also experienced fewer declines in their capability to perform daily tasks, were more likely to be able to live independently, and were less likely to be lonely and to rate their health as poor.
The findings appear in the Sept. 14 issue of the journal Archives of Internal Medicine.
By improving cardiovascular fitness, slowing loss of muscle mass, reducing fat, improving resistance and suppressing inflammation, physical activity may delay the onset of decline that can begin when a person is no longer able to perform daily activities, the study authors suggested.
"Despite the increasing likelihood of comorbidity, frailty, dependence and ever-shortening life expectation, remaining and even starting to be physically active increases the likelihood of living longer and staying functionally independent and Hebrew University," wrote Dr. Jochanan Stessman and colleagues at Hebrew University Medical Center Hadassah Medical School in Jerusalem.
"The clinical ramification are far-reaching," they added. "As this rapidly growing sector of the population assumes a prominent position in preventive and public health measures, our findings clearly support the continued encouragement of physical activity, even among the oldest old. Indeed, it seems that it is never too late to start."
The research included almost 1,900 people born in 1920 and 1921 who were assessed at ages 70, 78 and 85. Those who did less than four hours of physical movement per week were considered sedentary, while those who exercised about four hours a week, did vigorous activities such as swimming or jogging at least twice a week, or those who got regular physical activity (such as walking at least an hour a day) were measured physically active.
The researchers found that 53.4 percent of participant were physically active at age 70, 76.9 percent at age 77, and 64 percent at age 85. Compared to those who were sedentary, physically active people were 12 percent less likely to die between ages 70 and 78, 15 percent less likely to die between ages 78 and 85, and 17 percent less likely to die between ages 85 and 88.
Physically active participants also experienced fewer declines in their capability to perform daily tasks, were more likely to be able to live independently, and were less likely to be lonely and to rate their health as poor.
The findings appear in the Sept. 14 issue of the journal Archives of Internal Medicine.
By improving cardiovascular fitness, slowing loss of muscle mass, reducing fat, improving resistance and suppressing inflammation, physical activity may delay the onset of decline that can begin when a person is no longer able to perform daily activities, the study authors suggested.
"Despite the increasing likelihood of comorbidity, frailty, dependence and ever-shortening life expectation, remaining and even starting to be physically active increases the likelihood of living longer and staying functionally independent and Hebrew University," wrote Dr. Jochanan Stessman and colleagues at Hebrew University Medical Center Hadassah Medical School in Jerusalem.
"The clinical ramification are far-reaching," they added. "As this rapidly growing sector of the population assumes a prominent position in preventive and public health measures, our findings clearly support the continued encouragement of physical activity, even among the oldest old. Indeed, it seems that it is never too late to start."
Monday, September 14, 2009
MONDAY, Sept. 14 (HealthCare Tips) -- Swimming in pools disinfected with chlorine may increase the odds that a child will develop asthma or allergies, new research suggests.
The study found that youngsters who spent more than 1,000 hours swimming in chlorinated pools, either indoors or outdoors, had more than eight times the risk of having asthma than did teens who primarily swam in pools using a copper-silver disinfect method.
"Chlorinated pool attendance has a very significant impact on the occurrence of allergic diseases in the studied population," said lead author Alfred Bernard, a professor of toxicology and research director at Catholic University of Louvain in Brussels, Belgium.
"When used properly, [chlorine] is an efficient and safe disinfectant for swimming pools. However, when too much chlorine is added to water or builds up in the air of indoor pools, there is unavoidably some frustration of the organs of the bather in contact with the water and air," he explained. "There is now increasing facts that these irritating effects may be detrimental to the airways of regular swimmers, especially the children who are the most weak and the most frequent attendees of chlorinated pools."
Results of the study will be published in the Sept. 14 online issue of Pediatrics.
More than 17 million people in the United States have asthma, according to the American Academy of Allergy, Asthma and Immunology. Symptoms of the disease include wheezing, shortness of breath and coughing. The airway disease can be caused by a number of factors, such as cold air, exercise and chemical irritants. While chlorine has long been known to be an airway irritant and potential trigger of asthma, particularly in indoor pools, Bernard's study suggests that chlorinated pools might play a role in the growth of asthma and allergy.
The study included 847 Belgian youngsters between the ages of 13 and 18. All had attended indoor or outdoor swimming pools, but at various rates of attendance. One hundred and fourteen children mainly attended pools that were kept clean with a copper-silver disinfect, rather than chlorine. The remainder primarily attended pools disinfected with chlorine.
The number of children who ever had asthma went up in amount to their chlorinated pool exposure. Teens who swam for 100 to 500 hours in chlorinated pools had an 80 percent increased risk of having asthma, while those who logged 500 to 1,000 hours had just over twice the risk. When teens spend more than 1,000 hours swimming in chlorinated water, the risk of ever having had asthma nearly quadrupled. The risk of currently having asthma was more than eight times higher in the group with more than 1,000 hours in chlorinated pools compared to those who were rarely in chlorinated water, according to the study.
The risk of allergies also increased considerably when adolescents spent more than 100 hours swimming in chlorinated pools. In fact, the risk of hay fever and other allergies more than doubled with important chlorinated pool exposure.
Dr. Jennifer Appleyard, chief of allergy and immunology at St. John Hospital and Medical Center in Detroit, said this study highlights the fact that "asthma and allergies are caused by a multitude of different factors, and chlorine may have a potential effect. But, this is a very preliminary study, and we don't yet know what the whole picture is."
She said that she wouldn't advise parents to stop taking their kids swimming, even if they have asthma already. "If your kids have asthma and you know chlorine is a trigger, it's a good idea to try to limit their disclosure, but you can't exclude your child from everything and every potential trigger. You have to let them be kids."
If you know your child is worried by chlorine exposure, and they have an event such as a birthday party that they really want to attend, talk about it with your child's doctor to find out the best way to manage the exposure.
Bernard said that if you have a backyard pool, you should use as little chlorine as you can to safely disinfect the pool. He said that many people over chlorinate their pools to get clear blue water. But, he said, "chlorine is a disinfectant, not a cleaning agent."
The study found that youngsters who spent more than 1,000 hours swimming in chlorinated pools, either indoors or outdoors, had more than eight times the risk of having asthma than did teens who primarily swam in pools using a copper-silver disinfect method.
"Chlorinated pool attendance has a very significant impact on the occurrence of allergic diseases in the studied population," said lead author Alfred Bernard, a professor of toxicology and research director at Catholic University of Louvain in Brussels, Belgium.
"When used properly, [chlorine] is an efficient and safe disinfectant for swimming pools. However, when too much chlorine is added to water or builds up in the air of indoor pools, there is unavoidably some frustration of the organs of the bather in contact with the water and air," he explained. "There is now increasing facts that these irritating effects may be detrimental to the airways of regular swimmers, especially the children who are the most weak and the most frequent attendees of chlorinated pools."
Results of the study will be published in the Sept. 14 online issue of Pediatrics.
More than 17 million people in the United States have asthma, according to the American Academy of Allergy, Asthma and Immunology. Symptoms of the disease include wheezing, shortness of breath and coughing. The airway disease can be caused by a number of factors, such as cold air, exercise and chemical irritants. While chlorine has long been known to be an airway irritant and potential trigger of asthma, particularly in indoor pools, Bernard's study suggests that chlorinated pools might play a role in the growth of asthma and allergy.
The study included 847 Belgian youngsters between the ages of 13 and 18. All had attended indoor or outdoor swimming pools, but at various rates of attendance. One hundred and fourteen children mainly attended pools that were kept clean with a copper-silver disinfect, rather than chlorine. The remainder primarily attended pools disinfected with chlorine.
The number of children who ever had asthma went up in amount to their chlorinated pool exposure. Teens who swam for 100 to 500 hours in chlorinated pools had an 80 percent increased risk of having asthma, while those who logged 500 to 1,000 hours had just over twice the risk. When teens spend more than 1,000 hours swimming in chlorinated water, the risk of ever having had asthma nearly quadrupled. The risk of currently having asthma was more than eight times higher in the group with more than 1,000 hours in chlorinated pools compared to those who were rarely in chlorinated water, according to the study.
The risk of allergies also increased considerably when adolescents spent more than 100 hours swimming in chlorinated pools. In fact, the risk of hay fever and other allergies more than doubled with important chlorinated pool exposure.
Dr. Jennifer Appleyard, chief of allergy and immunology at St. John Hospital and Medical Center in Detroit, said this study highlights the fact that "asthma and allergies are caused by a multitude of different factors, and chlorine may have a potential effect. But, this is a very preliminary study, and we don't yet know what the whole picture is."
She said that she wouldn't advise parents to stop taking their kids swimming, even if they have asthma already. "If your kids have asthma and you know chlorine is a trigger, it's a good idea to try to limit their disclosure, but you can't exclude your child from everything and every potential trigger. You have to let them be kids."
If you know your child is worried by chlorine exposure, and they have an event such as a birthday party that they really want to attend, talk about it with your child's doctor to find out the best way to manage the exposure.
Bernard said that if you have a backyard pool, you should use as little chlorine as you can to safely disinfect the pool. He said that many people over chlorinate their pools to get clear blue water. But, he said, "chlorine is a disinfectant, not a cleaning agent."
Labels: Risks of chlorine in pools
