Air pollution and the risk of dementia



by LORENZO CIOTTI

Air pollution and the risk of dementia

Dementia is a neurological condition characterized by the onset, following various brain pathologies, of a decline in multiple cognitive functions, a decline in memory and at least one cognitive function among the following: deficits in executive functions, language, to recognize objects and people, praxic functions.

The cognitive deterioration must be of such gravity as to make the patient no longer autonomous in daily activities, being the state of alert consciousness. In patients with dementia it is frequent to observe personality changes, which manifest themselves as behavioral disturbances, including apathy, behavioral disinhibition, episodes of agitation.

The Air Pollution and the Risk of Dementia: The Rotterdam Study, published in the Journal of Alzheimer's disease : JAD, told us: "Exposure to air pollution has been suggested to increase the risk of dementia, but studies on this link often lack a detailed screening for dementia and data on important confounders.

To determine the association of exposure to air pollution with the risk of dementia and cognitive decline in the population-based Rotterdam Study. Between 2009 and 2010, we determined air pollutant concentrations at participants residential addresses using land use regression models.

Determined air pollutants include particulate matter, a proxy of elemental carbon (PM2.5 absorbance), nitrogen oxide (NOx), and nitrogen dioxide (NO2). As the individual air pollutant levels were highly correlated, we computed a general marker covering all air pollutants based on a principal component analysis.

We followed participants up for dementia until 2018 and determined cognitive performance during two subsequent examination rounds. Using Cox and linear mixed models, we related air pollution to dementia and cognitive decline.

Of the 7,511 non-demented participants at baseline, 545 developed dementia during a median follow-up of 7 years. The general marker of all air pollutants was not associated with the risk of dementia, neither were the individual air pollutants.

Also, the general marker of all air pollutants or the individual air pollutant levels were not associated with cognitive decline. Conclusion: In this study, we found no clear evidence for an association between exposure to air pollution and the risk of dementia or cognitive decline."