The Journal of the American Medical Association has published a study that found lead exposure to cause adverse neurological conditions leading lower IQ scores among individuals. The study states that 94 percent of Americans, exposed to leaded gasoline in childhood, demonstrate lower IQ scores and socioeconomic status in adulthood.
The researchers gathered and evaluated blood samples of more than 500 participants, grown up in the era of leaded gasoline. The research revealed that participants indicated with more than 10 micrograms of lead per deciliter of blood, at age 11 had significantly reduced IQ scores in adulthood.
Furthermore, the research says that participants, exposed to a higher amount of lead, exhibited IQs that were 4.25 points lower than the individuals with less exposure at age 38. Lead exposure has a dose-dependent effect on the IQ levels of the participants. As per the study, each 5-microgram increase in blood lead levels causes a 1.5 IQ point loss in participants.
Moreover, the exposure reportedly lowers the socioeconomic status in adulthood. The participants with 10 micrograms of lead in the blood obtained occupations with socioeconomic status four-tenths lower than those who had less exposure.
The Centers for Disease Control and Prevention (CDC) declares that five micrograms per deciliter is the current lead exposure value that requires public health intervention. 94 percent of the research participants exceeded this rate. According to the CDC, four million American households have children exposed to high levels of lead. Plus approximately half a million U.S. children, between one to five, have blood lead levels higher than five micrograms per deciliter.
Lead exposure to cause serious neurological damage
This respective study is one of its kinds enumerating the association between lead exposure and adverse neurologic conditions.
Back in 2009, a study found that lead exposure in children causes permanent brain damage in adulthood. Researchers pooled data from the Cincinnati Lead Study. 33 adults with high lead exposure in infancy and childhood were evaluated. They showed histories of low IQ, juvenile delinquency, and criminal arrests. Functional magnetic resonance imaging tests were carried out. The tests suggested that participants needed to stimulate additional brain regions for the completion of two tasks designed to assess the brain’s executive functioning.
The lead author Kim explains that the area of the brain, responsible for inhibition, is damaged when exposed to lead. Thus, the other regions of the brain had to work hard to compensate for the performance of the individual. He further mentioned that lead exposure has harmful and lasting effects that are difficult to reverse. The findings of the study were presented at the annual meeting of the Radiological Society of North America.
Consumer goods to elevate the risks of lead exposure
At present, food appears to be a major contributor to lead exposure in the U.S. Even the USDA-certified organic foods have been found to contain heavy metals. More than 1,000 consumer goods and food products were evaluated in the laboratory. All of the products like staples such as rice protein products were revealed to have high levels of lead and cadmium in them.