Lead exposure in last century shrunk IQ scores of half of Americans: study (today.duke.edu)

Article summary

A study found that exposure to lead from car exhaust in the last century may have resulted in a loss of 824 million IQ points among more than 170 million Americans alive today. The researchers used data on childhood blood-lead levels, leaded-gas use, and population statistics to estimate the lifelong burden of lead exposure. Leaded gasoline was banned in the US in 1996, but those born before then may be at greater risk for lead-related health problems. The study suggests that lead exposure may have affected cognitive ability and increased the risk of health impairments.

Main themes

• lead exposure
• IQ loss
• crime rates
• public health
• environmental factors
• cognitive ability

What commenters say

• The removal of lead from gasoline may have contributed to the decline in crime rates in the latter half of the 20th century.
• The link between lead exposure and crime rates is not entirely clear and may be influenced by other factors.
• The decline in crime rates since the 1990s may be attributed to various factors, including the removal of lead from gasoline, but also other social and economic changes.
• Some argue that the current rise in crime rates may be due to factors such as stress, anxiety, and economic hardship, rather than lead exposure.
• The impact of lead exposure on cognitive ability and health may be more significant than its potential link to crime rates.
• The relationship between lead exposure and empathy is speculative and requires further research to establish a clear connection.
• The increase in incarceration rates may be due to tougher sentences for non-violent crime, rather than an actual increase in crime.
• The decline in crime rates may be a result of a combination of factors, including the removal of lead from gasoline, rather than a single cause.