THE ESSENTIAL
- Inhalation of lead particles disrupts brain development and cognitive abilities
- Adding lead to car gasoline until 1996 contaminated millions of Americans
- The average loss of IQ amounts to 3 points per citizen of the United States
Americans have just learned that they have paid a tribute as heavy as it is unexpected to the reign of the queen automobile: the pollution born of the exhaust gases containing the lead dust which was one of the components of gasoline until in 1996 would have deteriorated the level of the intelligence quotient of 170 million citizens of the United States, that is to say nearly half of the population of the country! This is revealed a work carried out by Florida scientists and published in the journal of the National Academy of Sciences.
According to this work, the exposure of Americans during their childhood to the exhaust fumes of cars running on leaded gasoline would cost them a loss of 824 million collective IQ points. Figures that mean nothing before being explained: this total drop in the level of IQ represents an average individual loss of 3 points per person, which can potentially make those who originally have intellectual capacities a little lower than the average in the category of intellectually disabled!
Particles harmful to brain development
Leaded gasoline was banned in 1996. But everyone born before that date – and especially those born in the 1960s and 1970s when fuel consumption peaked – had exposures to lead at through the particles contained in the exhaust gases of cars which are of great concern. In addition to their effects on cardiovascular health, these lead particles affect brain development and cognitive abilities. Lead is indeed a neurotoxin that erodes brain cells when it enters the body. And it affects all ages, although children are particularly vulnerable.
“Lead is able to reach the bloodstream when inhaled as dust and it passes into the brain through the blood-brain barrier“, underlines Aaron Reuben, one of the authors of the study.
Up to 7 IQ points lost for the most exposed children
This was conducted using data on children’s blood lead levels in the United States, lead gas use and population statistics. Combining this data helped determine the likely level of lifetime lead exposure for every American living in 2015. And that’s where the IQ loss numbers came in: up to 6 points for people born in the mid to late 60s having the highest lead levels and even 7 points for the most exposed children.
“I was frankly shocked by these figures!“, admitted Michael Mc Farland, co-author of the study. There are indeed 170 million Americans who had clinically worrying levels of lead in their blood when they were children. the introduction of lead in gasoline intended for cars in 1923 was intended to preserve the good health… of engines!