Every year on the 22nd of July, the World Federation of Neurology (WFN) stages World Brain Day, an awareness-raising initiative involving more than 120 organisations from around the globe. This year, World Brain Day sets its sights on air pollution and its catastrophic effects on brain health.
Recent data estimates that air pollution is responsible for an astonishing 6–7-million deaths per year1, while countless more will suffer neurological damage as a result of pollutants. “The Global Burden of Disease study, carried out by an international team using data from 188 countries, found that up to 30% of the global stroke burden can be traced back to pollutants in the air,” notes Mohammad Wasay, World Brain Day Chair.2 “This was the reason behind our decision to select an aspect of environmental pollution as the theme for World Brain Day 2018.”
Air pollution – which can be defined as diffuse, often invisible contamination by damaging aerosols containing pollen, spores, particles and toxic substances – can stem from natural or man-made sources, and varies in both quantity and severity depending on a variety of factors. Outdoor pollutants such as industrial and vehicle exhausts, waste incineration and dust are perhaps more commonly thought of when talking about “air” pollution, but indoor pollution must also not be ignored, such as that caused heating systems, cooking (especially open wood fires), kerosene and tobacco. In fact, the World Health Organisation has determined that more than three billion people use harmful fuels in their homes for cooking and heating.
But how do pollutants affect the brain? In recent years, research has advanced the knowledge base significantly, but there are still many questions left unanswered. Looking at strokes in particular, it is now fairly clear that particulate matter (a mixture of solid particles and liquid droplets found in the air) can directly affect the vascular system, causing oxidative stress, inflammation, and eventually stroke.1
On the other hand, while epidemiological studies and animal models have suggested that prolonged exposure to air pollutants can increase the risk of dementia, the mechanisms are unclear, as are the effects of confounding factors such as diet and physical activity.1
At the cellular level, air pollutants can interfere with mitochondria and even with DNA, shortening telomeres and affecting chromosomal health. As such, there is growing concern that air pollution may play a devastating role in autism, ADHD and Parkinson’s, although hard data are still lacking.
Clean air at the forefront of our minds
For William Carroll, WFN President, the apparent link between pollution and brain health is a clear message that significant action needs to be taken: “Each and every one of us, every country in the world and the international community must see this as a wake-up call,” he said in the lead-up to World Brain Day. “Policymakers need to do more to tackle neurological disorders and diseases. This means making brain health one of the highest level healthcare priorities and providing additional funds to address the issue.”
Wolfgang Grisold, the WFN’s secretary general, added: “This worldwide public health problem requires effective environmental and health policy strategies aimed at reducing air pollution. It is not just a matter of lung health, but the health of the very organ that makes us humans: our brains.”
World Brain Day takes place on 22 July. More information can be found here!
- Air pollution and brain health: an emerging issue. The Lancet Neurology, 2018;17(2):103
- World Federation of Neurology. 22 July: World Brain Day 2018 – Clean Air for Brain Health. Available at: https://www.wfneurology.org/2018-07-18-wfn-wbd2018