Particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2) and black carbon (BC) endanger brain functions.
- Exposure to air pollution has been linked to an increased risk of dementia in a new study.
- The research was particularly long-term, following Danish nurses for 27 years, from 1993 to 2020.
- The risk of developing dementia increases by 35% for every 2.61 micrograms per cubic meter increase in PM2.5 levels.
A recent study published in the journal Alzheimer’s & Dementia revealed that women who live in unhealthy air are more likely to develop cognitive disorders.
Air pollution and dementia: a large-scale study
Particularly long, the research followed Danish nurses for 27 years, from 1993 to 2020.
The sample consisted of nurses aged over 44 in 1993, with additional nurses added in 1999. Those who already had dementia were excluded from the cohort, resulting in a final sample of 25,233 women. The researchers used national registries in Denmark to identify the onset of dementia over time.
The study found that long-term exposure to a range of air pollutants, including particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), and black carbon (BC), was associated with an increased risk of dementia. For example, the risk of developing dementia increased by 35% for every 2.61 micrograms per cubic meter increase in PM2.5 levels. These associations remained significant even after adjustments were made to account for factors that may influence these results, such as noise pollution.
Interestingly, the study also found that nurses with high levels of physical activity had a lower risk of dementia when exposed to air pollution compared to their less active counterparts. This suggests that exercise could help mitigate the adverse effects of air pollution on cognitive health.
Air pollution and dementia: the limits of the study
However, the survey only included nurses, which limits the generalizability of the results to other populations.
Future research should therefore aim to include a more diverse sample, including men and people from different professional backgrounds. It would also be useful to explore the effects of other environmental factors on dementia and to study potential interactions between different pollutants.
The study, titled “Long-term exposure to air pollution and road traffic noise and incidence of dementia in the Danish Nurse Cohort”, was produced by Stéphane Tuffier, Jiawei Zhang, Marie Bergmann, Rina So, George Maria Napolitano, Thomas Cole-Hunter, Matija Maric, Sonja Antic, Jørgen Brandt, Matthias Ketzel, Steffen Loft, Youn-Hee Lim and Zorana Jovanovic Andersen.
“Dementia is not a specific disease. It is an umbrella term that describes a broad range of symptoms associated with a decline in memory or other cognitive abilities severe enough to reduce a person’s ability to perform daily activities,” noted InsermAlzheimer’s disease accounts for 70% of cases.
