Approximately 4 million live children are born each year in America, and by age six more than 15 percent of those children have clinically recognized physical or psychological neurodevelopmental defects. Here is a tabulation (some children have multiple defects):
Attention deficit hyperactivity disorder: 3 to 10 percent
Learning disability: 7
Chronic emotional or behavioral problems: 6
Speech defects: 5
Delay in growth or development: 4
Cerebral palsy: 0.2
An estimated 17 percent of American children under 17 years of age are reported to have at least one neuropsychological developmental disability. That's about 1 out of every 6 children, or 11 million children under the age of 17 in America with a neuropsychological developmental disability that affects behavior.
Such disabilities are usually diagnosed in the school-age population, and nearly all of them endure throughout the lifetime. Their prevalence among adults is unclear, but if we assume a prevalence in American adults the same as that in children (17 percent), we can estimate that more than 50 million Americans have at least one neuropsychological developmental disability.
Clinicians estimate that only about half of these cases are caused by chromosomal defects. If this is so, it implies that at least half the cases are a result of fetal or early childhood environmental causes--impacts of the environment on development. These impacts include maternal health problems during pregnancy and exposure to environmental toxic chemicals. That's at least 300,000 children a year afflicted with neurodevelopmental damage that may be preventable by adequate prenatal care and control of environmental toxic impacts.
The early damage continues in each new generation, so that in our current population of 300 million we can expect at least 22.5 million people with neurodevelopment defects that might have been prevented during gestation or in early childhood. Given all of this, it seems we're living in a society that's crippling itself by neglect--and without remedy the crippling will certainly get worse as the toxic soup of our environment becomes more dangerous in the absence of controls. Any alarm can be a false alarm. But as I've said elsewhere, when a smoke alarm goes off in your house in the middle of the night, it's prudent to get out of bed and find out what's going on.
Industry, the media, and government need to pay attention to this problem, but apparently that will not happen until the rest of us make it painful for them to do nothing. We can give thanks that this is still a democracy and that public pressure still works. It needs to work now, for your new children and your grandchildren and your great-grandchildren.