LD, ADHD, and Environmental Toxins

by Katy Abel

One Parent's Story: Lingering Doubts About Lead Exposure
Throughout her years in school, 13-year-old Alice B. has suffered reading delays, written expression disorder, and anxiety. Her frustrations in the classroom have sometimes culminated in angry behavior at home and psychosomatic illness, causing heartache for her entire family. Specialists have told Alice's mother, Elizabeth, that the child's various conditions are linked. What they can't tell her is what caused them.

From time to time, Elizabeth thinks back to the apartment the family lived in until Alice was four years old. Elizabeth didn't realize it, but the rooms were filled with lead paint. A younger son, tested shortly before the family moved out, had elevated lead levels. But Alice was never tested.

"It's my feeling it might have played a role (in Alice's learning delays)," Elizabeth speculates. But her daughter also had a complicated birth, which could offer another explanation for her problems. "That's where it gets murky. Either or both of those things could be the reason."

Parents like Elizabeth often confront a profound sense of inner guilt when mulling over the possible causes of their child's developmental disabilities. Nagging questions and self-doubt persist: Should I have had her tested earlier? Should we have disciplined him differently? Are these problems attributable to genes or, as a growing chorus of scientists and concerned child advocates are now asking, could toxic chemicals in the environment be threatening children's neurological development?

Lacking Science, Gaining Common Sense "While it's of scientific interest to sort all of this out, and hopefully we'll continue to do this over decades, there's a very plausible argument to be made for simply being very careful to eliminate unnecessary (chemical) exposures given what we know right now," says Dr. Ted Schettler of Greater Boston Physicians for Social Responsibility, a lead author of In Harm's Way: Toxic Threats to Child Development.

A growing body of research suggests that chemicals released into the environment may at least partially explain the alarming increase in birth and developmental defects now seen in American children. According to In Harms Way, 17 percent of all kids now suffer from learning, developmental, or behavioral disabilities. While there's clear evidence that toxic agents such as lead, mercury, or PCBs can have an adverse effect on a child's developing nervous system and cognitive abilities, far less is certain about the neurotoxicity of pesticides and many organic solvents commonly used in the home.

"We don't have any developmental data on many of these chemicals that are being released into the environment," says Dr. Schettler. "We need science, but absent the science, we should not be exposing kids."

The EPA requires manufacturers to prove that their chemicals do not cause cancer or birth defects, but there's no mandate to test for effects on a child's nervous system. In fact, since 1992, the Environmental Protection Agency itself has tested only 9 pesticides for their neurotoxic effect on children. Some 350 pesticides are on the market, currently used on food crops. Environmental and children's advocacy groups say the issue is critical, because many pesticides are deliberately designed to attack an insect's nervous system. The human body has many of the same neurotransmitters.

"It's very hard for people to believe, but when EPA requires testing of chemicals sold in any grocery or hardware store, they look at the acute poisoning of a rat," says Eric Olson, senior attorney for the Natural Resources Defense Council. "Does the rat go into paralysis or begin twitching? They have not looked at how the chemical delays development or affects learning. It's obviously a huge gap."

Another problem is that chemicals are only tested singly, not in combinations, even though chemical interactions can produce adverse effects. Researchers and physicians also bemoan the fact that environmental, social, and genetic research is often done in isolation, even though there's clear evidence of interaction between genetic and environmental factors.

"An example would be a child who, because of his or her genetic makeup, tends to absorb lead through the intestinal track more readily, or excrete it less quickly, so a given amount of lead in one child will have a greater impact on one child than another," says Dr. Schettler.

The Politics of Testing
While the scientific community moves forward with calls for more comprehensive research, advocacy groups fear that the federal government will be slow to heed the call for expanding testing.

"It's a concern of a lot of people within EPA that they'd have to fight major battles with multinational corporations that have a lot of ability to block action they might take," observes the National Resources Defense Council's Olson, a former EPA staffer. "There's also inertia and an unwillingness to change the way things have been done. And I would say judging from the way the Texas environmental authorities regulated during the Bush administration, there's good reason for concern about what will end up happening at EPA."

In the meantime, experts say parents are best advised to assume that a chemical approved as safe by the EPA, in many cases decades ago, may in fact be harmful to children and pregnant women. The only solution is to avoid needlessly exposing children to chemicals, especially pesticides, wherever and whenever possible. Sprays, bombs, and foggers should not be used inside a home, Olson recommends.

Online Resources
To download a copy of In Harms Way: Toxic Threats to Child Development, visit the Clean Water Fund's website at cleanwaterfund.org.

For information about toxic chemicals and children's health, visit the website of the Natural Resources Defense Council at nrdc.org and the Institute for Children's Environmental Health at iceh.org.

For a complete list of pesticides currently on the market, visit the Environmental Protection Agency website at epa.gov.

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