17. Toxins and Environmental Pollution Contribute to Human Aggression Society

Sources: RACHEL'S ENVIRONMENT & HEALTH WEEKLY, Titles: "Toxins Affect Behavior"; "Toxins and Violent Crime" Dates: January 16, 1997, #529; June 19, 1997, #551, Author. Peter Montague, Ph.D.

SSU Censored Researcher: Deb Udall
SSU Faculty Evaluator: Noel Byrne, Ph.D.

It may come as no surprise that exposure to toxic pollutants -- chemical substances and heavy metals -- is hazardous to your health. But according to two recent studies that examined the relationship between exposure to toxins and aggressive behavior, such exposure -- which is usually preventable -- has been linked to violence in society.

A 1996 study conducted by Herbert Needleman, published in the Journal of the American Medical Association, took into account nine variables including poverty level and minority status, as well as lead exposure, in trying to explain aggressive behavior in young boys. Needleman's study found that boys with high amounts of lead in their bones had more reports of aggressive and delinquent behavior than boys with low levels, and that their behavior got worse over a period of time, regardless of social factors.

New research by Roger D. Masters and colleagues at Dartmouth College suggests exposure to toxic pollutants --specifically lead and manganese -- may contribute to people committing violent crimes. Masters developed the "neurotoxicity hypothesis of violent crime," which he hoped would help to explain why violent crime rates differ so widely between geographic areas. Masters also found that environmental pollution and high alcohol use have a strong effect on violent crime. U.S. counties with measures of neurotoxicity -- lead, manganese, and alcohol -- have violent crime three times the national average. "The presence of pollution is as big a factor as poverty," said Masters in a May interview in New Scientist. "It's the breakdown of the inhibition mechanism that's the key to violent behavior."

Despite government attempts to regulate the potential dangers of environmental exposure to toxins, such as outlawing lead in gasoline and tin cans and requiring lead paint disclosures, in 1994, an estimated 1.7 million American children ages one through five had blood lead levels of 10 micrograms per deciliter of blood (ug/dl) or more. Among African-American children in large cities, 36.7 percent have blood lead levels of above 10 ug/dl. Reduced IQ power can be measured when lead is as low as 7 ug/dl, but any amount of lead exposure seems to diminish mental power in children. Brain damage from lead exposure persists for many years, and IQ reduction is essentially permanent. An estimated 20 percent of American children now exhibit mental or behavioral problems.

The main source of toxic lead in children today is in dust and soil, with much of it coming from the lead-based paint of older buildings. The Centers for Disease Control (CDC) calculated that American taxpayers could realize a net profit of $28 billion in social savings and increased productivity by removing all lead-based paint from old buildings.

UPDATE BY AUTHOR PETER MONTAGUE, PH.D.: "This story reveals the failure of government to require adequate testing of new chemicals while it expands the list of serious problems thought to be caused by toxic pollutants. To my knowledge, there is little new [on this subject], except an increased appreciation for the effects of chemicals on human behavior. I believe that this new view of pollution will become more widespread in the next few years. In the past, if pollution didn't kill us or make us sick, it was considered 'safe' -- or at least benign. Now we are coming to learn that certain pollutants can affect our behavior -- in this instance, making some of us more violent than we might otherwise be. There is also a growing body of evidence suggesting that pollutants can affect our sexual behavior (enhancing or diminishing libido, for example). I believe we are seeing the tip of the iceberg here.

"To my knowledge, this story has been completely ignored by the mainstream press."