Could the negative effects of air pollution get any worse? Well, for some time now, poor air quality has been a key subject for scrutiny by many researchers. In fact, aside from causing respiratory issues, recent revelations point to a connection between air pollution and the dreaded Alzheimer’s disease.
What is Alzheimer ’s disease?
Alzheimer’s disease entails a neurological disorder whereby the death of brain cells leads to cognitive decline and memory loss or what is commonly referred to as dementia. It can occur in middle or even old age and is the most common cause of premature senility.
Can air pollution really cause dementia or Alzheimer’s disease?
Air pollution generally consists of several components such as metals, chemical compounds, gases, and tiny particles or otherwise known as particulate matter. Most of the research exploring the link between poor quality air and dementia focuses on the fine particulate matter, which is referred to as PM 2.5. These tiny particles are known to be 40 times smaller in size compared to the width of a human being’s hair.
Recently, three researchers from the Arizona State University (ASU) penned a working paper that argued that extended exposure to poor quality air increases the chances of dementia as opposed to just respiratory problems. As such, they recommended that better air quality could result in longer and improved lives. Furthermore, the research work entailed studying 15-years’ worth of health records for about 7 million American adults before comparing the data gathered to that on cumulative residential exposure to PM2.5.
The ASU researchers attributed the size of particulates with a diameter that is less than 2.5 microns to be the reason why such particles stay airborne for prolonged durations. According to their paper, this attribute allows them to be easily inhaled, leading to accumulation within an individual’s brain tissue. In turn, the buildup results in neuroinflammation, commonly associated with dementia symptoms.
Even though the three ASU economists are convinced that there exists a link between air pollution and dementia, they were not able to explain the biology behind how PM2.5 get into the brain tissues and what they do there. Another unsolved concern is whether there is a specific type of fine-particulate (PM2.5) air pollution connected to dementia. In the US, for instance, increased dementia results from various causes including automobile emissions in some areas and emissions from coal burning in other areas among others.
What do past studies show?
Air pollution has been a major concern across the globe. For that, there have been several studies looking at the connection between poor air quality and dementia including one involving dogs and mice living in polluted locations. Exposing mice to traffic pollution in a laboratory setting led to deteriorated motor skills, learning ability and memory. The research suggested the existence of a link between air pollution and cognitive impairment.
A more compelling 2016 study focusing on 6.6 million Canadians showed an impressive link between individuals living near busy roads and dementia. The study showed that living close to a busy road posed a small risk of developing dementia compared to people living further away.
Although all these studies do not conclusively show that air pollution directly causes dementia or Alzheimer’s disease, it goes without saying that further research on the matter ought to be done.