Leaded Gasoline and IQ Loss

The introduction of unleaded gasoline in the 1970s was due to health concerns related to lead. Leaded gasoline was phased out of use in the United States on January 1, 1996, with most other countries following suit. A 2022 study revealed that childhood exposure to leaded gasoline resulted in a loss of 824 million IQ points for over 170 million Americans. On average, individuals experienced a loss of 2.6 IQ points, with those born in the mid to late 1960s potentially losing up to six IQ points. Children with the highest levels of lead in their blood may have lost more than seven IQ points on average.