Kim Cecil, a scientist at Cincinnati Children’s Hospital Medical Centre in his study reports, being exposed to lead in childhood can result in permanent brain damage, with no region of the brain spared and distinct areas of the brain affected differently.

For the study, the researchers recruited 33-adults, average age 21, who had been enrolled in the long-term Cincinnati Lead Study (between 1979 and 1987) when they were infants, for studying
376-infants with pre-natal and early childhood exposure from high-risk areas of Cincinnati.

The blood lead levels of the study participants with a mean of 14, ranged from 5-micrograms to 37-micrograms per decilitre, and who had IQ deficiencies and histories of juvenile delinquency and criminal arrests.

The brains of the participants’ were monitored with the help of functional MRI, as they performed two tasks for assessing their attention, decision making and impulse control. The scans revealed, for completing a task requiring inhibition, participants who had levels of lead in their blood, needed activation from additional regions of the brain’s frontal and parietal lobes.

‘This tells us that the area of the brain responsible for inhibition is damaged by lead exposure and that other regions of the brain must compensate in order for an individual to perform. However, the compensation is not sufficient,’ Cecil said.

Cecil believes, the white matter of the brain, organizes and matures at an early age, including adapting to lead exposure. On the other hand, the frontal lobe is not only the last to develop, it also suffers permanent damage from lead exposure, even as it matures.

‘Many people think that once lead blood levels decrease, the effects should be reversible, but, in fact, lead exposure has harmful and lasting effects,’ Cecil said.

The study will be presented Tuesday at the Radiological Society of North America annual meeting to be held in Chicago.