Air Pollution Linked to Cognitive Decline in Low-Middle-Income Countries

Strategic Insights -

Research conducted by University of Michigan School of Public Health investigators, published in the journal Environment International, reveals a significant association between particulate air pollution and cognitive decline in low-middle-income countries. The study analyzed data from India's Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD) and found that higher concentrations of total particulate matter (PM2.5) and PM2.5 from specific emission sources, including energy production, industry, and residential combustion, were linked to accelerated cognitive decline. The study's findings suggest that interventions targeting residential sources of PM2.5 could help reduce or delay the onset of dementia in these settings.

Key Takeaways:

  • Particulate air pollution from different emission sources, including energy production, industry, and residential combustion, was associated with steeper cognitive declines over time.
  • Higher concentrations of total PM2.5 were not associated with cognitive performance at baseline but were associated with faster declines over time (-0.012/year per SD, 95 % CI: -0.021, -0.004).
  • PM2.5 from residential combustion sources was specifically linked to accelerated cognitive declines, suggesting that interventions in these sources might reduce or delay the onset of dementia.
  • The study utilized data from the 2017-2019 and 2022-2024 waves of the LASI-DAD study, with 5,699 participants (mean age: 70±8 years).
  • The research concluded that higher long-term total ambient PM2.5 concentrations and those from residential combustion sources were associated with accelerated cognitive declines, highlighting the importance of addressing air pollution in low-middle-income settings.

Statistics:

  • Total PM2.5 concentrations ranged from 16 to 206 mg/m3.
  • The study observed significant associations between higher concentrations of PM2.5 and cognitive decline in low-middle-income countries, with PM2.5 from residential combustion sources showing the strongest link.
  • The research included 5,699 participants, with a mean age of 70 years and a standard deviation of 8 years.

Sources:

  • Zhang, B., et al. Particulate air pollution from different emission sources, cognitive performance, and cognitive declines in India. Environment International, 2025, 204(): 109826.
  • Our news journalists report that additional information may be obtained by contacting Boya Zhang, University of Michigan School of Public Health, United States.