Air pollution from fires and farming have been linked to increased dementia risk. 

New research highlights a connection between fine particulate matter (PM2.5) air pollution and a heightened risk of dementia among older individuals. 

Notably, the study points to a stronger association between dementia risk and air pollution originating from wildfires and agricultural activities. 

The findings stem from an investigation using data collected over a decade from nearly 30,000 participants in the United States. During the study period, 15 per cent of the cohort developed dementia. 

The study reveals that individuals residing in neighbourhoods with higher levels of PM2.5 were more prone to developing dementia. 

This discovery builds upon a growing body of evidence suggesting a link between air pollution and cognitive decline, particularly dementia. 

The investigation, known as the Environmental Predictors of Cognitive Health and Aging study, draws on data collected biennially between 1998 and 2016 from the Health and Retirement Study, a nationally representative cohort in the US.

The researchers delved into the impact of various emission sources of PM2.5 on dementia incidents. 

They discovered that higher residential concentrations of total PM2.5 were linked to a higher likelihood of incident dementia, particularly when emissions resulted from agricultural practices and wildfires. However, the relationship between dementia risk and other sources of PM2.5 emissions, such as traffic, coal combustion, and agriculture, became less significant when adjusted for other factors.

The researchers say their study underscores the need to address PM2.5 pollution as a means of promoting cognitive well-being among older adults. 

The findings indicate that interventions targeting the sources of pollution, especially agriculture and wildfires, could offer valuable avenues for reducing dementia risk. 

Nevertheless, the researchers highlight the necessity for further research to validate and enhance understanding of these connections.

The full paper is accessible here.