Comprehensive study: We know little about environmental effects on kids


An unprecedented effort to compile everything the medical and scientific community knows about how children differ from adults in terms of their biologic vulnerability to environmental agents such as lead, mercury, pesticides, and smoke makes clear how little is known about how environmental factors affect children.

The 200-page supplement, sponsored by the Environmental Protection Agency, is the most comprehensive, authoritative publication ever produced regarding ways that environmental factors affect children's health. Scheduled for an April 5 release, it is an exhaustive research effort involving contributions from more than 40 leading pediatric experts, each of whom wrote about how environmental agents and toxins affect children.

Michael Weitzman, M.D., executive director of the American Academy of Pediatrics' Center for Child Health Research at the University of Rochester Medical Center, led the effort with co-editor Robert Brent, M.D., Ph.D., D.Sc., of Thomas Jefferson College in Philadelphia. Brent contributed several papers to the effort, including "Environmental Causes of Human Congenital Malformations" and "The Pediatrician's Role and Responsibility in Educating Parents about Environmental Risks."

"The most significant finding from this research is that we now realize how very little we know about how environmental factors affect children, and that is a major concern," says Weitzman, an internationally recognized expert on childhood exposure to lead and smoking. "For instance, we know far more about the effects of prescription drugs on children versus adults than we know about how environmental factors impact children as opposed to adults."

"People are just starting to address the environmental contaminants that are present, says Gary Myers, M.D., a pediatric neurologist at the University of Rochester Medical Center who was co-author of a supplement paper titled "Mercury exposure and childhood developmental outcomes." "The issue has not been looked at very carefully until now, but during the past few years, it's been a growing concern for a lot of people."

"Even when we are talking about lead – the most studied neurotoxin in the history of mankind – we do not know if there are certain ages when children are more vulnerable to its effects," Weitzman says. "The fact that the Environmental Protection Agency (EPA) commissioned such a compendium regarding children's health is a terrific first step, but we need to carry the momentum forward. Hopefully, these findings will serve as a springboard for the national research agenda regarding children and environmental exposure."

Researching the effects of environmental factors on children's health can be a frustrating process filled with obstacles, physician-researchers say. For instance, when trying to ascertain whether environmental agents in housing are affecting the health of children living there, it is often difficult to conduct the study before gut instinct tells researchers that the family should move to protect their children.

In fact, the dilemma is so far-reaching that the prestigious Institute of Medicine – which advises the federal government about numerous health-related topics – recently convened a committee charged with examining the ethics of research involving housing and children. "We are doing experiments in people's homes, trying to learn more for the sake of our kids," Weitzman says. "But if you go into somebody's home and you know that their children are being exposed to potentially harmful chemicals, what do you do?"

It would be unethical to give toxins to children to study their effects, Myers says. "So we are always left with the question, 'What was the actual exposure?' You have to determine exposure in some other way, such as a blood test. People are working hard to find new ways to determine exposures, but the fact is, it is a very difficult task."

Understanding the effects of environmental toxins is especially important today. "If there were a bioterrorism attack in the United States, we may know something about what to do to help adults, but at this point we know virtually nothing about what we would do to help children," Weitzman says. "We don't know how children absorb biochemicals from their skin. The EPA extrapolates data from adults into data from children, but their patterns of exposure are different – they are smaller, closer to the ground, and their organs are developing."

Many assumptions take place when trying to evaluate the impact of chemicals and drugs on children, says John Benitez, M.D., managing director of the Finger Lakes Regional Poison and Drug Control Center, based in Rochester, N.Y. "Historically, it was assumed by many that if a certain drug or chemical had an effect on a human adult, then a similar effect would occur in the child," he says.

"This was true whether we are talking of exposure to an environmental toxin or of a potentially curative drug," Benitez says. "It is also assumed that if a certain antidote can be used in an adult, then it must be an option for children, even though an adverse-effect profile has not been done on that age group. We have a critical need for specific information as to the effect chemicals and drugs have on children, and what effects certain antidotes or cures at different doses have on children."

Because environmental health often involves huge amounts of money, there may be a fair number of people who don't want to acknowledge the importance of this supplement, Weitzman says. "But our hope is that people – whether they are physicians, parents, or business owners – will take the information we have presented, as well as information we learn further down the road – and use it for good."

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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It is never too late to give up your prejudices.
-- Henry David Thoreau