#MHForAll Webinar: Air Pollution, Brain and Mental Health
On Tuesday 20th August, the Global Mental Health Action Network partnered with the Health Effects Institute to host an important webinar exploring the impact of air pollution exposure on brain and mental health. Our expert speakers discussed the current evidence base, including new research on the harmful effects of air pollution on dementia, psychotic symptoms, mood disorders, and suicide rates.
Expert Speakers:
Pallavi Pant, Head of Global Health, Health Effects Institute (Chair)
Joanne Newbury, Research Fellow, University of Bristol
Burcin Ikiz, Chair of the International Neuro Climate Working Group, Columbia University
Tamma Carleton, Assistant Professor of Environmental Economics, UC Berkley
Session Notes:
The State of Global Air Report has been tracking long-term trends in air quality and health impacts including data for each country; health outcomes; types of pollutants etc. It is available in multiple languages. The latest report findings show 1 in 8 deaths in 2021 were linked to air pollution exposure (8 million deaths) with the greatest numbers in South Asia and Africa. Air pollution can cause chronic disease and it tends to impact the youngest and oldest in society. Air pollution is linked to brain health and mental health, for example, air pollution increases the risk of dementia. This webinar looks at science and ways to reduce the burden of disease.
Evidence of links between air pollution and mental ill health
Two examples from the UK were shared. The first looked at nearly 14,000 service users with psychotic and mood disorders and their exposure to air pollution in the three months when they had their first episode and how much they used mental health services (community and in-patient) following their first episode. Every 25% increase in air pollution was associated with 11-18% more in-patient service use; and between 7-32% community service use within the first year and use continued beyond this period. The second example looked at pregnant women and their children and concluded air pollution and noise pollution are associated with increased psychotic symptoms and mood disorders including depression for adults and children.
Air pollution enables toxins to enter the brain
More than 90% of the global population is exposed to air pollutants that exceed WHO guideline limits. Air pollution (and factors such as extreme heat or smoke from wildfires) makes our blood/brain barrier leaky enabling toxins to enter the brain. This causes neuroinflammation leading to degeneration and it can affect grey matter too (i.e. our memory and ability to perform complex tasks). Air pollution impacts on brain health throughout our lifetime and can be intergenerational i.e. where pregnant women are exposed it can lead to premature birth and impaired child development including both mental and physical ill health. The number of people living with dementia is likely to significantly increase due to air pollution.
Suicides can be averted if air pollution is reduced
Global average suicide rates have been falling across the world and particularly in China. By looking at “inversion events” where pollution exposure levels are highest, it is possible to try and single out the impact of air pollution on mental ill health. The evidence gathered shows the impact on different age groups, for example, suicide rates among women over 65 years old significantly increase (by a rate of 65%) when air pollution increases. The evidence also shows the immediate impact of air pollution on suicide rates: when air pollution increases, suicide rates increase in the same week. However, the positive conclusion of these studies is that if pollution is reduced then suicide rates can be reduced. Evidence from China also shows 46,000 suicides have been averted due to reductions in air pollution over 5 years (but this is only 10% of the overall decline of suicide rates in China so other factors are also key to reducing suicide rates).
The panel’s recommended actions include:
Research - develop interdisciplinary teams, focus more on LMICs
Advocacy - mobilise health professionals and do educational campaigns with policy makers
Policy - develop policies that address prevention, and incorporate screening and response
Engagement - engage people with lived experience and/or those based in LMICs
The panel concluded with an agreement going forward: We all need to advocate for cleaner air in cities and towns; and bring together the data, stories and experiences of people to communicate to others the importance of tackling air pollution.
