Is Dementia Connected to Pollution?

Over the years, several studies have been conducted to determine the link between dementia and air pollution. In July last year, the UK Health Security Agency or UKHSA published an independent review that studied evidence linked to the adverse impacts of air pollution on the brain. Researchers reviewed around 70 human studies to collect the evidence they needed.

One of the first things the researchers discovered is the substantial increase in the number of dementia cases, which now totals to approximately 900,000. This covers a period of at least 15 to 20 years. They also came up with the conclusion that older people who are exposed to air pollution experience a decline in their mental and cognitive abilities. 

Researchers discovered that when an exposed person breathes in tiny particles of toxic air, these go to the bloodstream. When this happens, the blood vessels are irritated by the pollutants thereby causing a disruption in the circulation of blood to the brain. This can later develop into vascular dementia, the second most common type of dementia after Alzheimer’s disease.

While numerous studies have already proven how exposure to toxic air can lead to circulatory issues, strokes, and heart disease, researchers found that the evidence is now stronger. 

Around two in 10 individuals over 65 years of age develop a mild problem with their cognitive abilities. At least five to 10% of them will eventually have dementia. Researchers refer to dementia as a 21st century health and social global challenge. 

The Committee on the Medical Effects of Air Pollutants or COMEAP ended the report with the definitive conclusion that dementia and mental ability decline in seniors or older people are linked to air pollution exposure.


One of the most dangerous pollutants is tiny particulate matter called PM2.5. These particles are only 2.5 micrometres across in diameter. For purposes of visual comparison, imagine holding or looking at 3% of human hair width – that’s how tiny PM2.5 pollutants are. 

PM2.5 can be easily breathed in and reach the lungs. From the lungs, it can immediately travel through the bloodstream to reach the brain. Researchers believe that it is possible for PM2.5 to cause negative effects on the brain. While diesel exhaust entering the lungs showed evidence of a detrimental effect on the brain (through an inflammatory response) during animal tests, this has not been tested on humans yet.

As such, further studies are needed to establish clear evidence of how particulate matter specifically affects brain health and cognitive abilities. 

Nevertheless, the UK government continues to come up with ways to reduce toxic air and improve air quality. An Air Quality Grant worth millions is expected to help in creating programs and similar measures for improving air quality and benefitting communities, businesses, and schools that are significantly affected by high-level air pollution. The grant is applicable only for areas with toxic air levels that are over the UK legal limits. 

Additionally, the green industrial revolution of Prime Minister Boris Johnson has set the target date for halving PM2.5 legal limits – the year 2040. PM2.5’s maximum permissible level is currently at 20mcg/m3 but is expected to be cut down to 10mcg/m3. 

Vehicle emissions

Road transport is one of the active sources of PM2.5, but diesel vehicles emit more pollutants than one can imagine. Nitrogen oxide or NOx is a group of gases that includes nitrogen dioxide (NO2) and nitric oxide (NO). It is highly reactive and capable of producing acid rain, smog, and ground-level ozone, a toxic pollutant that can damage vegetation.

Aside from causing a decline in cognitive abilities, exposure to NOx emissions can also trigger mental health issues such as depression and anxiety. 

Common health effects include asthma, emphysema and bronchitis (and other respiratory issues), pulmonary edema, and breathing difficulties.

Nitrogen oxide exposure can also lead to serious health conditions, particularly COPD or Chronic Obstructive Pulmonary Disease, asphyxiation and laryngospasm, cancer, and cardiovascular illnesses. 

In recent years, hundreds of thousands of premature deaths have been linked to air pollution. Nine-year-old Ella Adoo-Kissi-Debrah’s death in 2013 was the first such case recognized by the coroner in the UK.

NOx is linked to the Dieselgate diesel emissions scandal that involves Volkswagen and other car manufacturers, such as British-based Vauxhall, BMW, and Mercedes-Benz.


The Dieselgate scandal started when US authorities allegedly discovered defeat devices in the Volkswagen Group’s Audi and VW diesel vehicles sold in the American market. A defeat device is used to manipulate emissions tests. The device detects when a vehicle is in testing and immediately reduces emissions to within the World Health Organization’s (WHO) legal levels.

What regulators will see is a high-performing and environmentally friendly vehicle but when driven outside the lab, on real roads, it emits unlawful levels of NOx. Volkswagen lied to and put their customers’ lives in danger. Allegedly, Vauxhall, BMW, and Mercedes also misled drivers.

Authorities advise affected car owners to file a diesel claim against their carmakers so they can be compensated for the inconveniences and dangers of defeat devices.

How should I start my diesel claim?

Only specific models manufactured in specific years are affected by the scandal, so before working with an emissions expert, check with first to find out if you are eligible to receive compensation. You’ll also find relevant information about what you need to do for your Vauxhall emissions claims.

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