It’s no secret that we’re living in a world of toxins. But if you’re unaware of exactly how dangerous these toxins are to our health, you might want to sit down for this. Dr. David Bellinger, a professor of neurology at Harvard Medical School, estimated that Americans have collectively lost around fourty-one million IQ points thanks to the toxins in our environment.

Bellinger compared intelligence levels among children whose mothers had been exposed to neurotoxins while pregnant, versus children whose mothers had not been exposed while pregnant. His results showed a total loss of 16.9 million IQ points. This was largely due to exposure of the most common pesticides used in agriculture, known as organophosphates. Bellinger and other experts believe that a number of toxins are damaging the brains of unborn children. They are lowering IQ’s and causing ADHD and autism spectrum disorder. These researchers believe that “children worldwide are being exposed to unrecognized toxic chemicals that are silently eroding intelligence, disrupting behaviors, truncating future achievements and damaging societies.”

mother and baby

So what toxins are we talking about?

1. Arsenic

Ground water riddled with arsenic affects around 750,000 people, many in South Asia. Arsenic is a semi-metallic element that occurs naturally in the earth’s crust, but exposure is a problem. Human exposure is causing cancer, blood vessel damage, abnormal heartbeat and other illnesses. Arsenic posioning affects the skin, liver, lungs and kidneys, and can eventually lead to death. Exposure to arsenic while pregnant can lead cause a miscarriage or birth defects. Children who are exposed to arsenic for a long period of time may have a diminished IQ.

2. Pesticides

Phillipe Grandjean, a Harvard colleague of Bellinger’s, urges pregnant women to eat organic food. He estimates that there are about 45 organophosphate pesticides on the market, and he says that most of them have the potential to damage a developing nervous system. An organophosphate pesticide called clorpyrifos was the most widely used insect killer in American homes until 1995. That year, Dow Chemical was fined by the EPA for hiding more than 200 reports of poisoning cases. Today, the pesticide is considered “moderately toxic” to mammals, but it is still widely used in agriculture. Eating organic while pregnant can reduce the exposure of these pesticides to an unborn child by 80 or 90 percent.

3. Lead

Before the damaging effects of lead were known, the chemical could be found in gasoline, children’s toys, house paints, batteries and even cosmetics. By the 1970’s, 88% of children had a level of lead in their blood that was twice the amount considered toxic. Environmental contamination includes mining, smelting and manufacturing. Lead exposure can affect nearly every part of the body, causing permanent damage to the brain and the nervous system. Specifically, lead affects brain development in children, causing a lower IQ, reduced attention span and severe antisocial behavior. Both the neurological and behavioral effects of lead poisoning are believed to be irreversible.

4. Mercury

High levels of mercury in the air often originate from power plants run by coal. Many of these power plants are located very close to urban areas and cities, threatening human health. Mercury severely damages the brain and nervous system, including the brain development of a fetus. Babies exposed to mercury in the womb can experience brain damage, vision problems and hearing problems. You can be exposed to mercury through skin contact or through the air. You can also be exposed by eating and drinking contaminated food and water.

5. Toluene

Toluene can be found in substances such as gasoline, acrylic paints, varnishes, paint thinners, adhesives, glues, rubber cement and shoe polish. Toxicity can occur from the inhalation of fumes or absorption through the skin. Factory workers aren’t the only ones at risk for toluene poisoning. Toluene can be found in hundreds of consumer products including hair dye. Toluene exposure to a fetus can result in loss of muscle control, poor balanced and decreased mental abilities.

How Toxins Affect the Brain


Researchers note that the rates of diagnosis of autism spectrum disorder and ADHD are increasing. Neurobehavioral development disorders affect 10-15% of births today. For a brain to properly develop, neurons must move in a precise sequence. These toxins, along with several others, have the potential to disrupt this sequence, greatly affecting brain development. Exposure to toxins, specifically as a fetus or a child, can cause permanent brain injury.

Grandjean compared the problem to climate change when he said, “we don’t have the luxery to sit back and wait until science figures out what’s really going on, what the mechanisms are, what the doses are, and that sort of thing. We’ve seen with lead and mercury and other poisons that it takes decades. And during that time we are essentially exposing the next generation to exactly the kind of chemicals that we want to protect them from.”

The Atlantic
Worst Polluted
World Health Organization
Environmental Health Perspectives
March of Dimes