It is known that air pollution is a risk factor for heart and respiratory diseases, however, it could also be linked to the development of memory disorders. According to an epidemiological study published in the British Medical Journal (BMJ), it is confirmed that air quality can have an impact on the development of neurodegenerative diseases.
The linkage between air pollution and dementia
The research carried out by experts from the University of London found the following linkage: older adults living in areas of London with the highest concentration of air pollution had a higher risk of dementia compared to the adult population whose homes are located in areas with better air quality (AQI)
To get this conclusion, the researchers used the health records contained in a CPRD (Clinical Practice Research Datalink) database, which since 1987 records data from medical centers in different areas of cities across the UK. Specifically, a sample of fewer than 131,000 patients between 50 and 79 years of age, who had never been diagnosed with dementia and were registered in general consultations located within the M25 ring of London.
What parameters have been taken into account?
Based on the residential zip codes of the patients in the sample, the researchers calculated the annual exposure for the following air quality parameters:
- Nitrogen dioxide (NO2)
- PM2.5 particles
- Ozone (O3)
However, other parameters such as the proximity of road traffic and the noise levels coming from it, have also been taken into account, using validated and certified modeling methods with recorded measurements.
During the follow-up period (eight years) 1.7% of the people in the sample (2,181) were diagnosed with some type of neurodegenerative disease: 39% with Alzheimer’s and 29% with dementia as a consequence of cardiovascular and cerebrovascular accidents.
The researchers associated the diagnoses with the environmental levels of NO2 and PM2.5 estimated in the homes of the patients at the beginning of the investigation.
Those patients, who lived in neighborhoods subjected to high levels of NO2 (41.5 µg / m3), registered a 40% high risk of dementia diagnosis, compared to those who lived in other areas with a lower level of the pollutant. A similar link was also found with PM2.5 levels. However, there is no evidence with the O3.
Researchers at the University of London have insisted that this is an observational study and the findings are only applicable to London. However, this research also invites us to reflect on how public health would gain if air quality were better.
The World Health Organization (WHO) has already warned that air pollution is currently at the highest levels: 9 out of 10 inhabitants breathe toxic air and more than 8 million people die due to diseases that are linked to air quality. For this reason, Smart Cities must adopt air quality monitoring solutions such as those installed by ENVIRA, a strategy to take into account to reduce these numbers.