In their new book, "Children & Environmental Toxins: What Everyone Needs to Know," Philip Landrigan and Mary Landrigan bring together research on the risks chemicals pose to children in the form of a guide for parents, policymakers and the public.
In an interview with Living on Earth’s Steve Curwood, Dr. Philip Landrigan, who is dean of global health and a pediatrician at the Icahn Medical School at Mount Sinai Hospital in New York City, discussed some of the problems and solutions facing children and parents today.
Steve Curwood: What has changed about childhood health issues today from generations ago?
Dr. Philip Landrigan: The big change today from 25 or 50 years ago is the extraordinary number of new man-made chemicals that have come into children's environment. These are chemicals [that] go into toys, cosmetics, soaps and household products and children are exposed to them every single day. The fundamental problem is that the government in this country is not doing a good job of protecting children against toxic chemicals. There is no enforced requirement in the United States that new chemicals be tested for safety or evaluated for toxicity before the chemicals come to market. The chemicals are simply given a free pass. ... Sadly, time and time again, we have found out the hard way that these chemicals damage children's health. We really must do a better job in this country of assuring chemical safety and protecting children's health.
Why do these chemicals pose such a risk to children's health?
Different chemicals have different health effects. Lead was one of the first toxic chemicals whose effects on children we discovered. We now know that lead damages children's brains. It causes loss of IQ, shortening of attention span [and] disruption of behavior. And we've come to learn that those effects happen even at the very lowest levels of lead exposure to children. Even a tiny dose of lead can be dangerous to a child's brain.
Another class of chemicals are known as endocrine disruptors. These are chemicals that interfere with the normal hormonal chemical signaling that takes place in a child's body, and these disrupters can have very negative effects on a child's development.
One class of endocrine disruptors are phthalates. Phthalates are man-made chemicals that are put into rigid plastics to make them flexible. Unfortunately, the phthalates don't stay in the plastics. They escape; they get into food. Like lead, phthalates can damage brain development and cause reduced IQ. And if phthalates get into a baby — especially if they get in by way of the mother during pregnancy, when the baby is still in the womb — these chemicals can mess up the development of the male reproductive organs in a baby boy and increase the risk of reproductive malformations.
A third class of chemicals common in the modern environment are brominated flame retardants. Flame retardants are in things like couches, carpets and computers. The problem is, they escape from those products and get into house dust. When a pregnant mom is exposed to these chemicals, they can get into the baby and cause brain damage to the baby, with reduction in intelligence. The same can happen to a young child.
What's the link between some of these chemicals and learning disabilities?
Over the past 15 or 20 years, we have learned that a number of man-made chemicals can cause learning disabilities in children. These include lead, mercury, polychlorinated biphenyls (or PCBs), brominated flame retardants, a number of pesticides, and, lastly a number of the endocrine disruptors, such as phthalates and bisphenol A. If these chemicals get into a young child or into a woman while she's pregnant, they can cause injury to the brain of the baby. That injury shows up when the child is 2, 3, 4 or 5 years old as slowed learning, diminished IQ, short attention span, disrupted behavior — sometimes even attention deficit hyperactivity disorder (ADHD) and autism.
Learning disabilities are now calculated to affect 1 out of every 6 children born in the United States — about 15 percent of all American children.
Why do some of these impacts take so long to manifest?
The understanding has grown in the last 15 or 20 years that negative exposures that occur to an infant in the womb or to a child in the first couple of years after birth can have negative effects all across the human life span. The very first studies that helped illuminate that question are studies of babies who were malnourished during pregnancy. Scientists in Great Britain, who were studying children who had been malnourished during World War II in Holland, found that when these children became 50 and 60 years old, they had very greatly increased incidence of hypertension, heart disease, stroke and diabetes.
Since that time, we've come to understand that what's called fetal programming — the changes in the expression of the genes in the infant in the womb — can be caused not only by malnutrition but also by toxic chemicals. Scientists are are beginning to explore this question now and map out how it happens. But I think it's becoming increasingly clear that toxic chemical exposures in early life are going to increase risk for a whole range of diseases when kids grow up, everything from heart disease to cancer to kidney disease.
Explain the concept called subclinical toxicity — that is, health problems without any obvious symptoms.
In the 1970s, during studies of lead, we first came to realize that even very low levels of exposure to a toxic chemical — levels that are too low to produce any obvious symptoms in a child — could still cause damage to the child. When we started doing that work back in the '70s, the theory on lead poisoning was that it either made a child very, very sick — coma, convulsions, even death — or the child recovered and that was the end of the story. But that seemed a little artificial to some of us and so we started to look at children with lower levels of lead.
Lo and behold, we found that these children had loss of IQ, behavioral problems, etc. That opened up the whole realization that low dose exposures to toxic chemicals could cause damage in children. That's now become a very general recognition. Almost any chemical you can think of has a range of exposures. Obviously, the worst exposures create the most severe disease, but even low dose exposures can cause real damage.
Is there a link between these chemicals and childhood cancers?
We know that benzene can cause leukemia. Other carcinogens include a chemical called 1,3-Butadiene, which goes into synthetic rubber and various solvents that are found in drinking water. The number of new cases per thousand children has been rising steadily for the past 40 years and more. We've seen a more than 40 percent cumulative increase in incidence of cancer over this time. But I don't think anybody can claim to know totally why rates of childhood cancer are going up. It still remains to be determined.
How can people protect themselves at home from dangerous chemicals?
The first thing people have to do to protect their children is to take a little time to educate themselves, just as you educate yourself before you buy a new car or a new house. You learn the basic operating systems. You have to read a little bit about lead, about pesticides, about air pollution and about the other toxic chemicals that can affect your child. When a parent is armed with that knowledge, they are empowered to protect their children against toxic chemicals.
Start with the big ones: Lead paint in older homes, built before 1977, is still a big problem in America. There are still millions of homes that have lead paint. If a parent finds lead paint in a place accessible to a child, they have to bring in somebody who knows what they're doing to remove or at least cover up that lead paint. The worst thing a parent can do is to try to remove it themselves because that creates a toxic lead-contaminated dust, which can cause severe poisoning.
Another thing that parents can do in their home is minimize the amount of pesticides that come into the home. One thing they can do is buy organic. I know full well that organic produce costs more than regular produce, but the gap is narrowing; organic is getting cheaper than it used to be. If you shop wisely, you can get organic for just a little more than conventional. The gain that results from eating organic is that families who do so have 90 percent fewer pesticides in their body.
Also, don’t immediately reach for the can of insecticide to get [rid] of pests or treat weeds on the front lawn. You can control cockroaches and other vermin in the home if you do what's called integrated pest management, which is an approach that minimizes chemicals and relies on cleaning up food and other debris that cockroaches feed on. When it comes to your front lawn, I always say to people, "Learn to live with a few dandelions. They're quite beautiful and in the springtime, you can make a salad or tea out of them."
Couples who are thinking about having a baby must take steps to protect the baby in the mother's womb against toxic chemicals. It's become common knowledge that moms shouldn't drink alcohol or take recreational drugs or smoke tobacco during pregnancy. Now, we're advising parents to take that kind of advice a step further. Eat fish. Fish are very, very important for the baby's brain growth. But eat the right fish. There are charts available, for example, from the Natural Resources Defense Council, the Monterey Bay Aquarium and other groups, which specify which are the safe kinds of fish and which are the dangerous kinds of fish. The dangerous fish have high levels of mercury and PCB. Pregnant moms should avoid those.
Finally, avoid pesticides when you're pregnant. Any pesticide that you spray in your house, on your lawn or in your garden when you're pregnant, is going to get into your baby, and that's not good.
How can parents help their kids avoid asthma?
Rates of asthma have more than tripled in American kids since the 1970s. One of the big drivers of asthma is air pollution. Children who live near highways or in polluted inner-city neighborhoods have substantially more asthma than kids who live in clean areas. There are several things parents can do. On days when the air pollution outside is really bad, keep the house buttoned up. Never, never smoke in the home or in the hallway outside the apartment, because that smoke is a powerful source of toxic chemicals that can trigger asthma in a child. If you have the freedom to choose to live in a place where the air is better, do so. I realize in a lot of cases that's simply not possible for economic reasons, but still, it's advice we always put out there and sometimes people can act upon it.
The upshot of all this is that parents who care about these issues have to act within their homes and act within their communities to protect their children. But they also have to consider getting involved more broadly — joining the PTA, running for office, making their voices heard in the public space, and, most of all, voting. Ultimately, if you want to protect your children, you have to vote, and you've got to put people into office who will take action to protect your children. You can't shop your way out of it. Smart shopping helps, but you can't shop your way out of dirty air. You need government to help you.
Editor's note: This interview has been condensed and edited for clarity.