A new study has found that lead in gasoline could be devastating to the health of Americans over the age of 25.
Researchers at Duke University in Durham, North Carolinaestimated that 170 million Americans born before 1996 could have lost a total of 824 million IQ points due to constant inhalation of lead in car exhaust.
Lead exposure is also likely a cause of cardiovascular and respiratory disease, although researchers have not been able to quantify collective harm in the same way that they could quantify cognitive problems and IQ scores.
While the US and UK have phased out the use of lead in gasoline, the lingering effects will harm the population for decades to come.
Leaded gasoline was widely used in the US until the 1990s, and a study found that exposure to the chemical likely cost the country more than 800 million IQ points per 170 million affected (file photo).
Aaron Reuben, Ph.D. at Duke and co-author of a study published Monday at PNAStold that most of the harm caused by lead is due to “inherited exposure” – people who were heavily exposed to lead before it was heavily regulated at the end of the last century.
In 1986, the US began phasing out the use of lead in gasoline, and in 1996 completely phased it out. A few years later, in 2000, the UK made the same decision.
Lead exposure is relatively minor today as it is highly regulated in everyday life. This was not 30-40 years ago.
Aaron Reuben (pictured), Ph.D. at Duke University, said that people between the ages of 40 and 70 suffer from the most dangerous levels of lead exposure.
“Almost everything in [40 to 70 years old] age cohorts were exposed to lead as children, which required treatment,” Reuben said.
“These people are alive and not so old.”
In particular, regular exposure to gasoline is likely to affect every American born in 1996 or earlier, that is, people aged 25 and over.
Reuben points out that the level of lead a person’s exposure to lead depends on the environment they grew up in, as the chemical causes the most damage when a person’s brain is still young and developing.
People who grew up near highways or in poorer, often black, communities were most likely to be hit the hardest.
Reuben says that those who believe they were likely exposed to large amounts of lead in their youth should not worry, but active steps should be taken to limit the damage that can be done to them.
“You can’t change what happened in the past,” Reuben said, noting that any impact that has happened has probably already happened.
Simple steps, such as regular exercise, quitting smoking, and drinking alcohol, can limit your exposure to lead.
The impact on each individual is limited – only a few IQ points are lost and only slightly increased risk of heart and cognitive problems.
Systemically, however, lead exposure poses major problems. The collective loss of intelligence by all Americans has a “brain drain” effect, making the population collectively less intelligent and innovative.
“The idea is that everyone exposed has probably lost a few IQ points from their potential,” Reuben said.
“For a human, the impact can be quite minimal… [for society] we will have fewer geniuses and more people in [cognitively] limited range.
Surges in conditions such as dementia, heart disease, and others also have long-term implications for a health care industry that is already understaffed.
Flint, Michigan became a model for US lead exposure after a long water crisis from 2014 to 2019 (file photo)
Lead is still present in American lives, but the public knows more about it than ever.
The Flint Water crisis has captured worldwide attention, and the city of Michigan, which reached dangerous levels of lead exposure from 2014 to 2019 in running water, has become a poster child for the dangers of lead poisoning.
However, Flint is not the only city suffering from lead-laden water. Data from the Natural Resources Defense Council show that 56 percent of Americans consumed lead-contaminated water in 2020.
While no one is as dangerous as Flint, this frequent lead exposure can still be dangerous, especially for the youngest Americans.
Reuben said removing lead from American lives would be costly, time-consuming and would require a lot of political will from the people. However, avoiding long-term consequences can be worth it.