New research led by the Barcelona Institute for Global Health indicates that childhood exposure to air pollution leads to diminished connectivity between key brain regions, underscoring the necessity for stricter pollution regulations to protect future generations.
A new study led by the Barcelona Institute for Global Health (ISGlobal) has revealed that children exposed to higher levels of air pollution in early and mid-childhood exhibit weaker connections between critical brain regions.
The study, recently published in the journal Environment International, underscores the potential impact of early life exposure to pollutants on brain development.
The research demonstrated that increased exposure to pollutants, such as particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2) and nitrogen oxides (NOX), at the participants’ residences led to reduced functional connectivity between and within specific cortical and subcortical brain networks.
These networks are crucial for various cognitive functions, including thinking, perceiving and controlling movement.
“This is one of the first studies to explore how air pollution affects brain connections at rest, using brain scans taken multiple times in a large group of children from birth,” first author Michelle Kusters, an ISGlobal researcher, said in a news release.
The study analyzed data from 3,626 children from the Generation R cohort in Rotterdam, the Netherlands.
Exposure to air pollution was estimated using statistical models combining actual measurements with environmental characteristics.
Resting-state neuroimaging was employed to assess brain connectivity around the ages of 10 and 14.
The analysis considered exposure periods from birth to three years old and the year before neuroimaging assessments.
Persistent Associations
The findings illustrated that greater exposure to air pollution from birth to three years old is linked to lower connectivity between the amygdala and cortical networks associated with attention, somatomotor function, which coordinates body movements, and auditory function.
Furthermore, increased PM10 exposure in the year before the neuroimaging assessment correlated with diminished functional connectivity between the salience and medial-parietal networks, which are key for detecting environmental stimuli and self-perception.
“These associations persist throughout adolescence, which may indicate persistent disruptions in the normal development of brain networks due to pollution exposure. This could affect emotional processing and cognitive functions,” added lead author Mònica Guxens, an ICREA researcher at ISGlobal.
Guxens emphasized the necessity for further research to confirm these findings and understand their exact impact.
Brain Volume Changes
A related study by the same research team investigated the relationship between air pollution exposure during pregnancy and childhood, and subsequent changes in brain volume through adolescence.
The study, involving 4,243 children from the Generation R cohort, found that exposure to fine particles (PM2.5 ) and copper during pregnancy was associated with a smaller hippocampus volume at age 8. The hippocampus is vital for memory function.
However, the research noted “compensatory growth” in the hippocampus as the children aged, suggesting that brain plasticity might mitigate some initial adverse effects of pollution exposure.
Despite these early impacts on hippocampal volume, no substantial associations were observed between air pollution and other brain volumes, such as white matter, cortical grey matter or the cerebellum.
Importance of Policy Changes
According to the researchers, these findings highlight the potential long-term effects of early-life air pollution exposure on brain connectivity and development.
“While some brain regions may exhibit compensatory growth, the persistent disruptions observed in functional networks highlight the need for further research into the mechanisms behind these changes,” Kusters added. “Given the widespread exposure to air pollution, these results reinforce the importance of policies aimed at reducing pollution levels, particularly in urban environments, to safeguard children’s brain development.”
The study is a crucial step in understanding the lasting consequences of air pollution on brain health, emphasizing the urgency for policy changes to protect the cognitive development of future generations.