Effect of Particulate Matter Concentration on Cognitive Decline in Urban Adults Over 35 in India: A Pilot Study

Neurodegenerative diseases, such as Alzheimer’s disease, are characterized by progressive cognitive decline and pose an increasing global health burden. While the link between air pollution and cognitive impairment is established in high-income countries, there remains a significant research gap in low- and middle-income countries (LMICs), where pollution levels are often higher. This study investigates the association between fine particulate matter (PM2.5) exposure and cognitive decline in adults over 35 years old residing in urban areas of India, compared to a U.S. urban cohort. Using a mixed-methods approach, cognitive function was assessed through a Google Form-based cognitive test adapted from the Montreal Cognitive Assessment (MoCA) guidelines, while pollution data were sourced from the Air Quality Life Index (AQLI). Statistical analysis revealed a significant difference in mean cognitive scores, with Indian participants exhibiting greater cognitive decline (mean score 22.2) relative to U.S. participants (mean score 26.1; p = 0.0001). These findings support the hypothesis that higher PM2.5 levels correlate with increased cognitive impairment in urban Indian adults. This study highlights the urgent need for expanded research on pollution-related neurocognitive risks in LMICs and informs public health policies aimed at mitigating environmental factors contributing to cognitive decline.