Education Impacts
Lead poisoning can severely impact children's learning abilities, executive functioning and behavioural regulation, often leading to problems with impulse control and aggression. Research also suggests a link between childhood lead exposure and increased rates of violence and crime later in life.
According to a study by the Center for Global Development, elevated lead levels in children may account for over 20 per cent of the learning gap between wealthier and developing nations. The harm caused by lead exposure extends beyond the individual, hindering a nation's overall progress and development.
Children with blood lead levels above 5 µg/dL may score 3-5 points lower on intelligence tests compared to their peers. This decline in IQ limits their future potential and opportunities. When cognitive impairments affect large populations, it leads to reduced creativity and economic productivity on a societal level, weakening both social and economic growth.
“I forget a lot of things while I’m studying,” Anik says.
Lead alters a child's brain
Source: Mary Gearing and Krissy Lyon, SITNBoston, Harvard University Graduate School of Arts and Sciences. See: https://sitn.hms.harvard.edu/flash/2016/deadly-biology-lead-exposure/
When calcium enters a neuron, the neuron releases neurotransmitters to send a signal to the next neuron. Lead can interfere with this process by:
- Blocking calcium entry into the neuron, which causes the neuron to release less neurotransmitter and send a weaker signal to the next neuron.
- Causing aberrant neurotransmitter release when calcium is not present.
Impacts of lead exposure on a child's brain can occur when their blood lead levels are even below 5 µg/dL.
How much is 5 µg/dL, which is considered high blood lead level?
Globally, lead exposure accounts for nearly 10 per cent of the burden of intellectual disability of unknown origin, and the effects are typically irreversible. While pharmacologic treatments, such as chelating agents, can help alleviate the most severe symptoms of acute high-level poisoning, a rigorous multi-centre randomized controlled trial revealed no improvement in intelligence for children with chronic, moderate exposure—levels commonly found in many parts of the world.
Imaging studies of adults who were exposed to high lead levels during childhood have demonstrated specific reductions in brain volume and alterations in microstructure. These changes can significantly affect the brain's ability to reorganize and form new neural connections, highlighting the long-term consequences of lead exposure on cognitive development.
In brief, lead exposure is widening the learning gap between affected children and their peers, and only through coordinated efforts from governments, civil society and the private sector can this issue be effectively addressed.
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