1. links between air pollution and mental health: the influence of air pollutants on the brain
Studies, for example by the Harvard T.H. Chan School of Public Health or the University of Chicago, link long-term exposure to air pollution with an increased likelihood of mental illness and health problems. In particular, particulates (PM₂,₅) and nitrogen dioxide (NO₂) are cited as responsible air pollutants, which can increase depression, anxiety and sleep disorders. We will discuss the results of the studies in more detail later.
Air quality & its effects on mental illness
There is evidence that air pollution can cause neurological inflammation and oxidative stress reactions in the brain, which in turn is associated with an increased risk of mental illness. Researchers therefore assume that air pollutants could also increase the risk of dementia and other neurodegenerative diseases.
Increase in depression & anxiety due to poor air quality
Air pollutants in indoor air can impair sleep. Poor sleep prevents the regulation of various neurobiological processes: e.g. the consolidation of memory content, the detoxification of the brain from harmful metabolic products or emotional stability and resilience. There is a risk of an increased release of stress hormones such as cortisol, which can trigger increased irritability, emotional instability and a reduced ability to regulate emotions, as well as an increased risk of depression and anxiety. Physical symptoms of depression can include persistent sadness, hopelessness, irritability, sleep disorders and concentration problems or even culminate in suicide.
Example studies on the connection between air pollutants and mental health
According to a study by the Harvard T.H. Chan School of Public Health, there is a link between higher levels of particulate matter and an increased risk of depression and suicide. The researchers found a 6 to 15 percent higher risk of depression in people living in areas with higher levels of air pollution compared to those living in less polluted areas.
In their study, researchers from the University of Chicago also associated a causality between increased air pollution, particularly due to increased levels of particulate matter, and a greater risk of bipolar disorder and depression.
In a large-scale meta-analysis, 25 studies from different countries were examined. The result: higher exposure to air pollution increases the risk of anxiety disorders. The data showed that the effects of air pollution on mental health were consistent across different population groups and regions.
2. specific air pollutants & their effects
particulates
particulatesalso known as particulate matter (PM), consists of small particles of different sizes and origins suspended in the air. These particles can be either solid or liquid. Depending on its particle size, particulates is divided into different categories. Where the subscript number describes the diameter of the particle. PM₁₀ has a particle size of 10 micrometers or smaller. These particles are small enough to be inhaled but can also include larger particles that can be filtered through the nose or mouth. particulates with a size of 2.5 are of particular concern as they can penetrate deep into the respiratory tract and even enter the bloodstream.
Origin & distribution
particulates comes from various sources: both natural and anthropogenic (human) origin. The dust is produced by:
- Combustion processes: such as coal, oil, diesel and other fossil fuels in power plants, industrial plants, heating systems and vehicles
- Industrial emissions: Industrial processes, especially in sectors such as metal processing, mining, construction and chemicals
- Traffic emissions: Exhaust fumes from vehicles, abrasion from tires and brakes
- Construction work
- agricultural activities: ploughing, harvesting and other agricultural practices, fertilizers, pesticides
- natural sources: Forest fires, volcanic eruptions, dust storms
Health effects on the brain
- Neuroinflammation: particulates can lead to inflammation in the brain. Studies suggest that inhalation of PM₂,₅ can lead to activation of the immune system in the brain, which contributes to chronic neuroinflammation. This in turn is associated with various neurological diseases.
- Oxidative stress: particulates can cause oxidative stress in the brain by promoting the formation of reactive oxygen species. Oxidative stress can damage cells and is associated with neurodegenerative diseases such as Alzheimer's and Parkinson's.
- Circulatory disorders: Exposure to particulates can impair the function of blood vessels and lead to circulatory disorders in the brain. This could increase the risk of strokes and other vascular diseases.
- Impairment of cognitive function: Studies have shown that high concentrations of particulate matter can be associated with cognitive impairment and an accelerated decline in cognitive function. This particularly affects older people.
- Increased risk of neurodegenerative diseases: There is growing evidence that long-term elevated levels of particulates may increase the risk of neurodegenerative diseases such as Alzheimer's and Parkinson's.
- Development of psychiatric disorders: Some studies suggest that particulates may also be associated with an increased risk of mental health conditions such as depression and anxiety.
Nitrogen oxides
Nitrogen oxides (NOx) are a group of gaseous compounds that contain nitrogen and oxygen. The two main types of nitrogen oxides are nitrogen monoxide (NO) and nitrogen dioxide (NO₂).
Sources & distribution
These compounds are often produced during combustion processes, primarily in vehicle engines and industrial plants, power plants and heating systems that burn fossil fuels such as gasoline, diesel, coal or natural gas. In agriculture, nitrogen fertilizers and certain farming practices contribute to nitrogen oxide emissions. Natural processes such as lightning discharges can also release nitrogen oxide into the atmosphere.
Nitrogen oxides can undergo chemical reactions in the atmosphere and transform into various compounds, including particles that can contribute to the formation of particulates . Nitrogen oxides also play a role in the formation of ground-level ozone, an air pollutant that can also have health effects.
Relationship to mental illness
Some mental health problems that may be linked to elevated levels of nitric oxide are:
- Depression & Anxiety: Some studies suggest that long-term exposure to air pollution, including nitrogen oxides, may be associated with an increased risk of depression and anxiety. However, the exact mechanisms by which air pollution could affect mental health problems are complex and may involve neuroinflammation, oxidative stress and other factors.
- Sleep disorders: Nitrogen oxides can impair sleep. Sleep disorders, in turn, can be associated with various mental health problems, including depression and anxiety.
- Cognitive impairment: There is some evidence that high concentrations of nitrogen oxides, may be associated with cognitive impairment and faster decline in cognitive function. This could have implications for mental health, particularly in older people.
3. preventive measures & solutions
You can improve indoor air quality by taking various measures to avoid consequences for your physical and mental health. Healthy indoor air can help to maintain a healthy mind and physical well-being. We recommend the following preventive measures and solutions to combat air pollution in the home:
- Ventilation: Regular ventilation is crucial to bring fresh air into the home and reduce pollutants. Open windows and doors, especially if you are cooking, there are a lot of people in the room, you are cleaning or using cleaning products.
- Air purifiers: The use of air purifiers can help to filter pollutants from the air. Make sure that the air purifier is designed for the specific pollutants you want to reduce.
- Use environmentally friendly cleaning products: Many conventional cleaning products contain Volatile Organic Compounds (VOCs), which can affect air quality. Instead, use environmentally friendly cleaning products or homemade cleaning solutions (e.g. vinegar water)
- Less use of fragrances: Fragrances in candles, air fresheners and cleaning products can also release VOCs. Therefore, use products with natural fragrances or avoid them altogether.
- Control humidity: Adequate humidity (ideally between 30% and 50%) can reduce the growth of mold. Use dehumidifiers when necessary and repair leaks to fix moisture problems.
- Environmentally friendly building materials: When renovating or building new homes, you should give preference to environmentally friendly building materials in order to minimize the release of harmful substances from furniture, paints and floor coverings.
- Regular cleaning: Regular vacuuming and mopping helps to remove pollutants and allergens. Use a vacuum cleaner with a HEPA filter.
- Plants: Houseplants can help improve air quality by filtering certain pollutants. Popular air-purifying plants include the green lily, hemp and ivy.
To be able to accurately assess the air quality, it is advisable to check it constantly. With an air measuring device such as the air-Q, you can detect air pollution and react to it.
It is important to note that research on this topic is still ongoing and that air pollution is only one of many factors that can influence mental health. Other factors include genetic predisposition, social structure, lifestyle, trauma and individual resilience. Nevertheless, the available evidence suggests that air pollution and mental health problems may be linked. Therefore, reducing air pollution could be a good basis for reducing the risk of mental health problems.
But please note: our recommended measures are preventative suggestions! Please seek medical help if you are already struggling with mental health problems.
