The major problem with air pollution is that most people are unaware of the danger it poses to them, meaning they are not in a position to protect themselves. Particularly because the long-term negative effects are barely perceptible to us, unlike perhaps a broken leg or acute poisoning, yet can lead to health damage and increased mortality, education is especially important here. And even if the air in cities of developing countries contains far more pollutants than in Western industrialized nations, the risk is also proven in the latter. With this article, I would like to provide you with the necessary data to recognize the real danger and offer you ways to protect yourself. Even if systemic changes are necessary for fundamental improvements in air pollution and a differently weighted relationship between economic and ecological decisions would be needed in politics, we are still able to significantly reduce exposure to toxic substances. Increasing air pollution poses a serious threat to the environment, destroying ecosystems, leading to climate change, minimizing biodiversity, impairing photosynthesis and crop yields through soil acidification, and last but not least, negatively affecting human health. Indoor air pollution is two to five times higher than outdoors. For example, the concentrations of some indoor pollutants have increased in recent decades, due to higher energy efficiency with reduced air exchange, as well as the use of synthetic building materials, furnishings, toys, household cleaners, personal care products, and pesticides. This is all the more significant given that we spend approximately 90% of our time indoors. And people who are more susceptible to air pollution – very young and elderly individuals, cardiovascular or respiratory patients – typically spend even more time indoors. Long- and short-term exposure to air pollution has various toxicological effects on humans, including respiratory and cardiovascular diseases, skin diseases, neuropsychiatric sequelae, eye irritation, and long-term chronic diseases such as cancer, as well as premature mortality and reduced life expectancy. The long-term effects of air pollution on the development of respiratory and circulatory system diseases and cancer are widely recognized. Even pre- and perinatally, air pollution can lead to premature births, lower birth weight, and impaired lung development, which are associated with respiratory diseases in children and adults. Furthermore, air pollution is implicated in brain diseases, as well as immune and hormonal system disorders and reproductive dysfunctions. For instance, exposure to traffic-related air pollution particularly affects the brain’s white matter, but also the gray matter and basal ganglia, which can lead to impaired synaptic functions, changes in neuronal morphology, and neuronal death. Exposure to particulate matter with a diameter of 2.5 µm and traffic-related air pollution specifically leads to a reduction in white matter in the frontal lobe, with particularly severe effects in the prenatal period and possibly myelin damage in older adults. All these exposures can lead to a decrease in mental development, global IQ, memory, attention, and academic performance, as well as a higher prevalence of attention deficit hyperactivity disorder and autism spectrum disorder, and in older adults, cognitive decline, dementia, and Alzheimer’s. Particularly in developing countries, indoor pollutants, e.g., from cooking, lead to cognitive disorders and are, for example, the second most common cause of premature mortality in India. The relationship between air pollution and an increased risk of ischemic stroke is controversially discussed. However, the extent to which various toxic substances in the air interact with each other or possibly with other toxic substances, for example from food, in the body is very difficult to research and represent statistically. Causes of air pollution include the use of industrial machinery, power plants, internal combustion engines, and cars. The latter are responsible for approximately 80% of current pollution. To a lesser extent, field cultivation techniques, fuel tank heaters, gas stations, and cleaning processes, as well as several natural sources such as volcanic and soil eruptions and wildfires, are involved. From Manisalidis I, Stavropoulou E, Stavropoulos A, Bezirtzoglou E. Environmental and Health Impacts of Air Pollution: A Review. Front Public Health. 2020;8:14.
Air Pollutants
According to the World Health Organization, the six main air pollutants include particulate matter, ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. These are responsible for approximately 9 million deaths per year. Other potential exposures arise from increased carbon dioxide and toxic mold.
- Particulate matter typically forms in the atmosphere as a result of chemical reactions between various pollutants, as well as from traffic, and can lead to acute nasopharyngitis. Long-term, it is associated with cardiovascular diseases and infant mortality. Exposure to particulate matter is the fifth leading risk factor for deaths worldwide (approximately 4.2 million deaths in 2015). The WHO reported 7 million deaths in 2018. Particulate matter ranges in size from 0.1 to 10 micrometers. The smaller the particulate matter, the more harmful it is. Even at a size of 2.5 micrometers, particulate matter enters the bloodstream from the lungs, increasing the rate of cardiovascular deaths through sustained oxidative stress, inflammation, and increased activation of the autonomic nervous system.
Antioxidants could potentially be taken or supplemented therapeutically through diet. Inhaling particulate matter affects blood pressure, heart rate variability, blood clotting ability, vascular tone, and promotes atherosclerosis and possibly the risk of stroke. A not-yet-peer-reviewed Harvard study from 2020 concludes that individuals who have lived for decades in a county with high particulate matter pollution have an 8%* higher probability of dying from COVID-19 than someone living in a region with just one unit (one microgram per cubic meter) less particulate matter pollution. Elderly or very young people, or patients with pre-existing cardiovascular or respiratory conditions, generally have an increased risk of illness. Nanoparticles, however, with a size of 0.1 micrometers, can bypass the blood-brain barrier via sensory nerves in the nasopharynx and tracheobronchial regions. Even if only small amounts of inhaled insoluble nanoparticles penetrate the brain, long-term exposure – possibly through traffic-related ambient air or metal fumes in the workplace – can lead to their accumulation in the brain, where they can exert neurotoxic effects and damage the central nervous system.
- Ozone: In addition to many negative impacts of ozone on the entire ecosystem, it causes biochemical, morphological, functional, and immunological disorders, especially in urban areas. Carbon monoxide is produced by the incomplete combustion of fossil fuels. It exacerbates the greenhouse effect. Inhaling carbon monoxide can lead to headaches, dizziness, weakness, nausea, vomiting, and ultimately loss of consciousness.
- Nitrogen Oxide: Nitrogen oxide is a collective term for nitric oxide (NO) and nitrogen dioxide (NO2). They are produced as exhaust from car engines and in power generation, penetrate deep into the lungs, and act as irritants there. The German Environment Agency points out that concentrations of nitrogen dioxide (NO2), e.g., from diesel engines, in ambient air have serious health effects.
In 2014, it was associated with approximately 6,000 deaths in Germany. Values above 0.2 ppm cause respiratory diseases, coughing, shortness of breath, bronchospasms, and even pulmonary edema. Values above 2.0 ppm impair the immune system, particularly T-lymphocytes (CD8+ cells and NK cells). Even short-term exposure to gas cooking is associated with immediate respiratory impairment in asthmatic women. Mitochondrial function in the brain can also be impaired in animal experiments on rats. Long-term exposure leads to chronic lung diseases and impaired sense of smell, as well as irritation of the eyes, throat, and nose. Nitrogen oxides increase the risk of developing diabetes, high blood pressure, and arteriosclerosis, and promote premature skin aging.
- Sulfur Dioxide: Sulfur dioxide is primarily released during the consumption of fossil fuels or industrial activities. It leads to irritation of the respiratory tract, bronchitis, mucus formation, and bronchospasm, as well as skin redness, tearing, and corneal opacity in the eyes, and a negative impact on existing cardiovascular diseases. Elderly people, children, and those with lung diseases are particularly at higher risk.
- Polycyclic Aromatic Hydrocarbons (PAHs): PAHs are very widespread. They are formed during the incomplete combustion of organic matter, such as in wildfires and engines, and are found in coal and tar. PAH compounds like benzopyrene, acenaphthylene, and fluoranthene are toxic, mutagenic, and carcinogenic.
- Volatile Organic Compounds (VOCs): These are produced by the use of new products and materials such as furniture, building materials, toys, and particularly pollute indoor air. VOCs in outdoor air are mainly attributable to industrial facilities. Due to their synergistic, antagonistic, or indifferent effects, the impacts of VOC exposure are difficult to predict. VOCs such as benzene, ethylbenzene, toluene, and xylene are carcinogenic. Short-term exposure causes irritation of the eyes, nose, throat, and mucous membranes. Long-term exposure can trigger toxic reactions. A predictable assessment of the toxic effects of complex VOC mixtures is difficult to estimate, as these substances can interact synergistically, antagonistically, or indifferently.
- Carbon Dioxide: Due to increasing thermal insulation, many indoor spaces accumulate high levels of carbon dioxide, especially when more people are present and ventilation is insufficient. This can lead to drowsiness, headaches, impaired concentration and cognitive performance, including decision-making and problem-solving, and respiratory symptoms in children.
Therefore, ensure regular ventilation and take breaks in the fresh air.
- Dioxins: Dioxins are produced from industrial processes, the consumption of fossil fuels, and during wildfires and volcanic eruptions. They accumulate in foods such as meat and dairy products, fish and shellfish, and in animal fatty tissue. Short-term exposure can cause skin changes; long-term exposure can lead to developmental disorders, impairment of the immune, hormonal, and nervous systems, infertility, and cancer.
- Toxic Mold: In 2016, the Society for Hygiene, Environmental Medicine and Preventive Medicine (GHUP), together with other scientific medical societies, medical associations, and experts, developed a guideline from the Association of the Scientific Medical Societies (AWMF) on “medical diagnostics for mold exposure in indoor environments.” This guideline views mold growth indoors as a potential health risk, even without a proven quantitative and/or causal link between the occurrence of individual mold species and health effects. According to the guideline, there is sufficient evidence for allergic bronchopulmonary aspergillosis, mycoses caused by molds, allergic respiratory diseases, asthma, allergic rhinitis, exogenous allergic alveolitis, and respiratory infections/bronchitis. Compared to other environmental allergens, the sensitization potential of molds is classified as low, with a prevalence of 3-10%. Poisoning can only occur with molds that produce toxins.
However, whether and to what extent this actually occurs depends on other factors, but indoor air concentrations are always very low. Risk groups that need to be protected are patients with immunosuppression, cystic fibrosis, and asthma. According to the guideline, from a preventive medicine perspective, mold damage in indoor environments should not be tolerated. Mold sensitization can negatively affect children with asthma. One study demonstrated the induction of multi-organ morbidity with long-term exposure to damp microorganisms, such as non-thyroidal illness syndrome (NTIS). Another study pointed to changes in inflammatory and immune system responses to specific molds and mycotoxins. However, the extent of the danger posed by mold is controversially discussed. For example, Chang and Gershwin (2019) conclude that there is no evidence that the presence of mycotoxins in the air is sufficient to cause any disease known to humans. Valtonen limits the problem to the assessment of humidity and mold hypersensitivity syndrome. Existing controversies surrounding mold hypersensitivity syndrome can, according to Daschner (2017), be attributed to the great variability of clinical symptoms and possible triggering factors related to mold and dampness. According to the AWMF guideline from 2016, from a preventive medicine perspective, mold damage in indoor environments should not be tolerated. If health impairment due to mold is suspected, a diagnosis, anamnesis, physical examination, conventional allergy diagnosis, and, if necessary, provocation tests should be performed.
- Lead: Lead is used in industrial facilities and emitted by some gasoline engines, batteries, radiators, waste incinerators, and wastewater. Metals, ore, and piston-engine aircraft, in particular, are responsible for air pollution. Lead poisoning is primarily a threat in developing countries. Lead is absorbed through respiration, the gastrointestinal tract, and the skin, and it crosses the placenta, posing a risk of cerebral edema in unborn babies. Newborns and children are extremely vulnerable even to minimal lead exposure, which can lead to learning disabilities, memory impairment, hyperactivity, or even intellectual disability. It accumulates in the blood, liver, lungs, skeletal, cardiovascular, nervous, and reproductive systems. Loss of concentration and memory, and muscle and joint pain can occur in adults.
Summary
Air pollution primarily arises from traffic, industry, and air travel, as well as from pollutants generated directly in our living spaces. Additional burdens can result from smoking, toxic molds, or house dust mites. There are also air pollutants from natural sources such as desert dust, etc. However, in cities, the pollution is many times higher than in nature, and city dwellers also spend most of their time indoors, where the concentration of some pollutants can be 2 to 5 times higher than outdoors. Reasons include energy-efficient building construction with reduced ventilation and the use of synthetic building materials, furnishings, personal care products, pesticides, and household cleaners. The ailments and diseases caused by air pollution are usually insidious and relatively unnoticed. The long-term effects of air pollution involve the development of respiratory and circulatory system diseases and cancer, as well as diseases of the nervous, immune, and hormonal systems, and it is implicated in reproductive disorders. From: Manisalidis I, Stavropoulou E, Stavropoulos A, Bezirtzoglou E. Environmental and Health Impacts of Air Pollution: A Review. Front Public Health. 2020;8:14.
9 Tips and Strategies
1. Whenever possible, try to use building materials and furnishings that have no or as few volatile organic compounds (VOCs) as possible, such as clay walls, clay paints or low-VOC paints, stone or wooden floors, naturally treated solid wood furniture, and, if possible, sofa sets without flame retardants, etc. Many flame retardants are health-hazardous and can accumulate in the blood or even in breast milk. Influence of the built environment on health (according to Mitchell CS, Hodgson MJ, unpublished data). From: Wu F, Jacobs D, Mitchell C, Miller D, Karol MH. Improving indoor environmental quality for public health: impediments and policy recommendations. Environ Health Perspect. 2007;115(6):953‐957. However, this clearly shows how financial differences impact health aspects, as biological building materials are expensive. Nevertheless – even without great financial wealth, you can do a lot for yourself. 2. Spend as much time as possible in nature, such as parks and forests, or, if possible, in your garden. 3. Regularly ventilate the rooms you are in. This ensures sufficient fresh oxygen. Also consider outdoor air pollution, meaning avoid rush hour traffic. The ideal times for ventilation are usually early morning and evening. 4. Use plants indoors and, if possible, in outdoor areas, as well as green roofs. Plants act as biological filters and have the ability to reduce particulate matter, as well as ozone and nitrogen dioxide levels. Pines, yews, and ivy, for example, are ideal. A green environment not only influences air pollution but also promotes stress reduction, cognitive recovery, physical activity, social interactions, noise reduction, and the regulation of heat and humidity. Ideally, have at least 15% plants in the house, including the garden. 5. Use an air purifier. I use a Baren HEPA air purifier B-785. This is suitable for small to medium-sized rooms. 6. Avoid polluted areas by minimizing your time on the road during peak traffic hours and avoiding busy roads. 7. Ensure good ventilation when cooking indoors. 8. Engage in physical or sports activities. If you exercise outdoors, do so in nature and away from busy areas. In summer, with elevated ozone levels, try to exercise in the morning, as levels usually rise in the afternoon. If you are at risk, e.g., have cardiovascular or respiratory diseases, you should consult your doctor beforehand. 9. In case of particulate matter pollution, antioxidants could also potentially be taken or supplemented therapeutically through diet, such as N-acetylcysteine (NAC) or carotenoids, etc. 10. Mold: Mold does not necessarily have to be harmful to your health, but it could be. Therefore, if you suspect it, you should take further steps (see above for possible symptoms). Mold can hide almost invisibly behind floorboards or window frames. If you suspect toxic mold, you can cheaply acquire culture plates and place them in the rooms/locations to be examined for about 90 minutes. Afterwards, seal them tightly all around with adhesive tape. After 6-8 days at room temperature, check if anything has grown in the culture media in the dishes. In case of positive results – especially dark fungi – you can have them examined together with a blood sample. An institute I use is the Institute for Medical Diagnostics Berlin-Potsdam. Please do not attempt to remove mold yourself unless you have thoroughly researched the matter. In the worst case, you could worsen the problem. Contact a mold expert. They will know how to successfully remove the mold completely.
