Our children today live in an environment that is fundamentally different from that of 50 years ago. In many ways, their world is better. In many ways, they’re healthier than ever before. Thanks to safe drinking water, wholesome food, decent housing, vaccines, and antibiotics, our children lead longer, healthier lives than the children of any previous generation. The traditional infectious diseases have largely been eradicated. Infant mortality is greatly reduced. The expected life span of a baby born in the United States is more than two decades longer than that of an infant born in 1900.
Yet, curiously, certain childhood problems are on the increase: asthma is now the leading cause of school absenteeism for children 5 to 17; birth defects are the leading cause of death in early infancy; developmental disorders (ADD, ADHD, autism, dyslexia and mental retardation) are reaching epidemic proportions – 1 in 88 children is now diagnosed with autism spectrum disorder. (Currently one of every six American children has a developmental disorder of some kind .) Childhood leukemia and brain cancer has increased sharply, while type 2 diabetes, previously unknown among children, is on the increase. And the cost is staggering – a few childhood conditions (lead poisoning, cancer, developmental disabilities –including autism and ADD – and asthma) accounted for 3% of total U.S. health care spending in the U.S. “The environment has become a major part of childhood disease”.
How can this be?
Today’s children face hazards that were neither known nor imagined a few decades ago. Children are at risk of exposure to thousands of new synthetic chemicals which are used in an astonishing variety of products, from gasoline, medicines, glues, plastics and pesticides to cosmetics, cleaning products, electronics, fabrics, and food. Since World War II, more than 80,000 new chemicals have been invented. It may be that future parents may be just as shocked by the kinds of exposures we’re living with as we are by these Marlboro cigarette ads from the 1950’s:
Scientific evidence is strong, and continuing to build, that exposures to synthetic chemicals in the modern environment are important causes of these diseases. Indoor and outdoor air pollution are now established as causes of asthma. Childhood cancer is linked to solvents, pesticides, and radiation. The National Academy of Sciences has determined that environmental factors contribute to 25% of developmental disorders in children, disorders which affect approximately 17% of U.S. children under the age of 18. The urban built environment and the modern food environment are important causes of obesity and diabetes. Toxic chemicals in the environment – lead, pesticides, toxic air pollutants, phthalates, and bisphenol A – are important causes of disease in children, and they are found in our homes, at our schools, in the air we breathe, and in the products we use every day.
What makes these chemicals such a threat to children’s health?
- Easy absorption. Synthetic chemicals can enter our children’s bodies by ingestion, inhalation, or through the skin. Infants are at risk of exposure in the womb or through breast milk. According to the Centers for Disease Control and Prevention (CDC), more than 200 high-volume synthetic chemicals can be found in the bodies of nearly all Americans, including newborn infants. Have you seen the slogan that states babies are born pre-polluted? Of the top 20 chemicals discharged to the environment, nearly 75 percent are known or suspected to be toxic to the developing human brain.
- Children are not little adults. Their bodies take in proportionately greater amounts of environmental toxins than adults, and their rapid development makes them more vulnerable to environmental interference. Pound for pound, children breathe more air, consume more food, and drink more water than adults, due to their substantial growth and high metabolism. For example, a resting infant takes in twice as much air per pound of body weight as an adult. Subject to the same airborne toxin, an infant therefore would inhale proportionally twice as much as an adult.
- Mass production. Nearly 3,000 chemicals are high-production-volume (HPV) chemicals – that means they’re produced in quantities of more than 1 million pounds. HPV chemicals are used extensively in our homes, schools and communities. They are widely dispersed in air, water, soil and waste sites. Over 4 billion pounds of toxic chemicals are released into the nation’s environment each year, including 72 million pounds of recognized carcinogens.
- Too little testing. Only a fraction of HPV chemicals have been tested for toxicity. Fewer than 20 percent have been studied for their capacity to interfere with children’s development. This failure to assess chemicals for their possible hazards represents a grave lapse of stewardship by the chemical industry and by the federal government that puts all of our children at risk.
- Heavy use of pesticides. More than 1.2 million pounds of pesticides — many of them toxic to the brain and nervous system — are applied in the United States each year. These chemical pesticides are used not just on food crops but also on lawns and gardens, and inside homes, schools, day-care centers and hospitals. The United States has only 1.3% of the world’s population but uses 24% of the world’s total pesticides.
- Environmental Persistence. Many toxic chemicals have been dispersed widely into the environment. Some will persist in the environment for decades and even centuries.
What does the industry say in their defense? The chief argument they use is that the amounts used in products are so low that they don’t cause harm. We now know that the old belief that “the dose makes the poison” (i.e., the higher the dose, the greater the effect) is simply wrong. Studies are finding that even tiny quantities of chemicals – in the parts-per-trillion range – can have significant impacts on our health. Add to that the fact that what the industry bases its “safe” exposure limits on is calibrated on an adult’s body size, not children’s body sizes.
We also now know that time of exposure is critical – because during gestation and through early childhood the body is rapidly growing under a carefully orchestrated process that is dependent on a series of events. When one of those events is interrupted, the next event is disrupted – and so on – until permanent and irreversible changes result. These results could be very subtle — like an alteration in how the brain develops which impacts, for example, learning ability. Or it could result in other impacts like modifying the development of an organ predisposing it to cancer later in life.
There is yet another consideration: The health effects from chemical pollution may appear immediately following exposure – or not for 30 years. So one could unwittingly be setting the stage for a devastating disease down the road.
And this is where it gets really interesting (or scary):
Each of us starts life with a particular set of genes, 20,000 to 25,000 of them. Now scientists are amassing a growing body of evidence that pollutants and chemicals might be altering those genes—not by mutating or killing them, but by sending subtle signals that silence them or switch them on at the wrong times. This can set the stage for diseases which can be passed down for generations. This study of heritable changes in gene expression – the chemical reactions that switch parts of the genome off and on at strategic times and locations – is called “epigenetics”.
Exposure to chemicals is capable of altering genetic expression, not only in your children, but in your children’s children – and their children too. Researchers at Washington State University found that when pregnant rats were exposed to permethrin, DEET or any of a number of industrial chemicals, the mother rats’ great grand-daughters had higher risk of early puberty and malfunctioning ovaries — even though those subsequent generations had not been exposed to the chemical. Another recent study has shown that men who started smoking before puberty caused their sons to have significantly higher rates of obesity. And obesity is just the tip of the iceberg—many researchers believe that epigenetics holds the key to understanding cancer, Alzheimer’s, schizophrenia, autism, and diabetes. Other studies are being published which corroborate these findings. For those of you who are interested, the book by Richard Francis makes a fascinating read.
 Boyle, Coleen A., et al, “Trends in the Prevalence of Developmental Disabilities in U.S. children, 1997-2008”, Pediatrics, February, 2011.
 Grady, Denise, “Obesity-Linked Diabetes in children Resists Treatment”, New York Times, April 29, 2012
 Walsh, Bryan, “Environmental Toxins Cost Billions in childhood Disease”, Time, May 4, 2011.
 Koger, Susan M, et al, “Environmental Toxicants and Developmental Disabilities”, American Psychologist, April 2005, Vol 60, No. 3, 243-255
 Polluting Our Future, September 2000, http://www.aaidd.org/ehi/media/polluting_report.pdf
 Sorensen, Eric, “Toxicants cause ovarian disease across generations”, Washington State University, http://news.wsu.edu/pages/publications.asp?Action=Detail&PublicationID=31607
 http://www.sciguru.com/newsitem/13025/Epigenetic-changes-are-heritable-although-they-do-not-affect-DNA-structure ALSO SEE: http://www.eeb.cornell.edu/agrawal/documents/HoleskiJanderAgrawal2012TREE.pdf ALSO SEE: http://www.the-scientist.com/?articles.view/articleNo/32637/title/Lamarck-and-the-Missing-Lnc/