A blood sample being taken from a 3-year-old girl in Flint, Michigan, to test for exposure to lead
JIM WEST/SCIENCE PHOTO LIBRARY
A review of 17 studies has found that the more lead people are exposed to in childhood or in the womb, the more likely they are to engage in criminal behavior later in life.
Lead exposure has decreased in many countries due to the removal of lead additives from gasoline, but there is no safe level of exposure – even small amounts are believed to be harmful.
It is estimated that 1 in 3 children globally have blood lead levels above 5 micrograms per deciliter, which can lead to decreased intelligence, behavioral difficulties, and learning problems that are irreversible.
In Mexico, for example, the main source of lead exposure is the addition of lead to pottery glazes. Other sources include lead pipes, electronic waste, and consumption of birds shot with lead pellets.
The decrease in lead exposure in many countries has corresponded with a decline in crime rates, leading to the suggestion that exposure to lead increases criminal behavior. However, more studies are needed to establish causality.
Researchers, including Maria Jose Talayero from the George Washington University, have analyzed 17 studies from around the world that directly measured individuals’ lead exposure and its connection to criminal behavior. While some studies found no links or only specific associations, most indicated a connection between lead exposure and later arrests or delinquent behavior.
Overall, these findings demonstrate an association between lead exposure and criminal behavior, but further research is needed to establish causality. Criminal behavior is a complex concept, influenced by numerous factors besides lead exposure.
Topics:
