Are Today's Teens More Toxic?

By J. Robert Hatherill, Ph.D.

Although most Americans believe that the steady diet of violence in the media is leading to a more violent world, in reality it may be a steady diet of heavy metals and pesticides that is sending teens over the edge.

Perhaps in addition to checking our children for guns and explosives we should be checking their blood for elevated levels of toxic chemicals. In particular we should check out those recent perpetrators of school violence--whether they be dead or alive--to find out if there was a biological root to their behavior.

Pollution causes some people to commit violent crimes: In our myopia, we've neglected this obvious possibility. Yet a rapidly expanding body of research shows that heavy metals such as lead and pesticides decrease mental ability and increase aggressiveness. Human behavior is so easily influenced by toxic chemicals that in the 1980s a new scientific discipline called behavioral toxicology came into existence.

Nonetheless, we continue to load up our water and food supplies with dangerous chemicals. When Congress banned the dumping of sludge into the oceans in 1992, the result was that sludge was plowed into croplands. The Columbine High School killers were 10 and 11 years old when this decision was made, and since that time we have routinely dumped heavy metals such as lead and cadmium, household chemicals, industrial chemicals, pesticides and disease-causing microbes into agricultural soil.

As a result, are we now fostering a new generation of violent gun thugs?

The dumping of sludge is just one example of the continuing degradation of our food supply. The use of pesticides has increased 33 fold since 1942. Recent studies show that trace levels of multiple pesticides cause increased aggression. Trace pesticide mixtures have induced abnormal thyroid hormone levels, which are associated with irritability, aggression and multiple chemical sensitivity.

Children are the most vulnerable to pollutants. Because they are growing rapidly and they are smaller, they absorb 40 to 50 percent more toxic leads than adults. Babies fed infant formula rather than breast milk absorb more heavy metals such as manganese. And calcium deficiency in childhood also increases uptake of lead and manganese. An article in a February 1996 issue of the Journal of the American Medical Association, titled "Bone Lead Levels and Delinquent Behavior," outlines the association between heavy metals in the body and behavior problems such as attention deficit disorder, aggression, and delinquency.

Still more worrisome: At least seven studies have demonstrated that violent criminals have elevated levels of lead, cadmium, manganese, mercury and other toxic chemicals in their bodies, compared with prisoners who are not violent.

Added to sludge and pesticides is the underlying problem of the transformation of our eating habits and food supply. In recent years, developments in food technology in the U.S. and other developed countries have led to sweeping changes in nutritional composition and amount of fiber in the diet.

Growing and processing food has become a gigantic mechanized industry, and the explosive increase in processing has stripped many essential nutrients and fiber from our food. A diet filled with low-fiber convenience foods leads to a greater uptake of pollutants such as mercury and PCB. Although PCB was banned in the 1970s, it still persists in the environment.

The New England Journal of Medicine reported in September 1996 that children exposed to low levels of PCBs in the womb grow up with poor reading comprehension, low IQs and memory problems. Parents who feed their families typical processed and commercial foods may be unwittingly contributing to these problems.

From 1984 to 1994 the number of youths under 18 who were arrested for murder tripled, according to the Department of Justice. It is time to look beyond the sociological roots of this trend to consider the profound changes in our food and water supply as a possible cause of violent behavior. We need to rethink our dependence on processed foods and the release of toxic materials into our agricultural environment.

Rather than directing all our attention to bitter debates on gun control and the violence in the entertainment industry, let's also consider the pressing need for a cleaner environment and more nutritious food.

Dr. Hatherill is a research toxicologist and faculty member of the Environmental Studies Department, University of California, Santa Barbara