|Is Pollution Making Our
There's no shortage of seriously bad press
when it comes to chemicals loose in the environment. They cause cancer. They create
disease. They mess with our hormones. They harm our babies. It's all in a hard days work
for your typical malevolent molecule. But that's not all they may be up to. According to
emerging reports, toxic chemicals may soon be adding something else to their resume, an
unsettling ability to mess with our heads and literally make us less intelligent.
As research into the ways chemical contaminants affect the body
grows more sophisticated, scientists have begun to find out that environmental toxins can
affect us mentally as well as physically. According to a number of recent studies, certain
pollutants are affecting human intelligence and behavior on a global scale.
A 5-year study at the University of Wisconsin in Madison found that
water contaminated with low levels of the common agricultural pesticides atrazine and
aldicarb altered thyroid hormone levels in the bloodstreams of mice. Researchers found
that ingesting various combinations of these chemicals (which are often found in water
supplies in farming regions) caused increased aggression as a result. Researchers noted
that PCBs and dioxins are known to cause similar thyroid changes and that attention
deficit and/or hyperactivity disorders in children, multiple chemical sensitivity,
irritability and aggressive behavior are all linked to thyroid hormone levels.
A study of 4 and 5 year-old children in Mexico noted decreased
cognitive abilities and increased aggressiveness in children exposed to pesticides.
Researchers studied two similar groups of Yaqui Indian children in Sonora, Mexico. One
group lived in an farming area receiving 45 or more pesticide sprayings a year. The second
group lived in nearby hills where residents farm without pesticides. The study found that
the pesticide-exposed children displayed much less physical endurance in a test to see how
long they could jump up and down. They also had poorer hand-eye coordination and could not
draw a simple human stick figure, something the hill children easily did. The study also
noted that "... valley children were observed hitting their siblings when they passed
by, and they became easily upset or angry with a minor corrective comment by a parent.
These aggressive behaviors were not noted in the foothills."
In a review of the evidence, Britain's Global Environmental Change
Programme found that lead, PCBs, biphenyls and radiation are harming the intelligence of
people around the world. This problem is compounded by food supplies that are suffering a
loss of micronutrients like iron and iodine. The report noted increases in Downs Syndrome
in areas affected by the Chernobyl explosion; decreases in intelligence among 95% of
children in uranium mining towns; decreases in intelligence of Inuit children exposed to
airborne PCBs; decreases in intelligence in Indian villages poisoned by fluoride-tainted
water; and the fact that 10% of English children and up to 90% of African children in
certain regions have high enough blood lead levels to affect intelligence.
The Greater Boston Physicians for Social Responsibility recently
called for tests to assure that chemicals do not affect brain functioning. The group says
that preliminary data shows that common household chemicals like glues, solvents,
pesticides, and others have the potential to harm the brain. According to the group,
chemicals currently must be tested to see if they alter the physical structure of the
brain, but no tests are required to see how brain functioning is affected. Their report
notes that of the approximately 15,000 common household chemicals on the market, only 12
have been tested for their effects on brain development.
While more research needs to be done, we're smart enough to believe
that something's going on. Before we all get a bit too addled in the head to know any
better, we suggest we all rethink our chemically-dependent ways and come up with some
brighter ideas. Here again, the Precautionary Principle must prevail and synthetic
chemicals assumed guilty until they can be proven innocent. It's the only intelligent
thing to do.
For more information visit http://www.preventingharm.org/