How Air Quality Affects Our Health in the Short and Long Term—and Why It’s About to Get Worse

Air quality is something many of us take for granted. But climate change can worsen air quality through wildfire smoke, ground-level ozone, longer pollen seasons, and more time spent indoors during hazardous outdoor conditions. At the same time, atmospheric CO2 concentrations continue to rise, while indoor CO2 can build up in poorly ventilated spaces and signal that ventilationThe process of circulating air to improve indoor air quality. is not keeping up with occupancy. The effects of poor air quality are not just long-term; they can also affect daily life and well-being in the short term. ¹WMO reports that globally averaged carbon dioxide concentrations continued to rise in 2024, with the largest one-year increase in modern records, driven by ongoing emissions and reduced natural absorption during a year affected by fires and climate variability. WMO, “Greenhouse Gas Bulletin No. 21,” https://public.wmo.int/sites/default/files/2025-10/GHG-21_en.pdf.

Here’s a look at how air quality impacts us now, the potential long-term consequences, and why our changing climate could make breathing clean airAir free of pollutants, including viruses, bacteria, and harmful particles. a bigger challenge than ever.

Short-Term Effects of Poor Air Quality

Poor air quality can have immediate effects on our health, and many people experience symptoms without even realizing they’re related to air pollution. Here are some of the short-term health impacts of breathing in polluted air:

1. Respiratory Irritation and Infections

Exposure to pollutants like particulate matter (PM2.5 and PM10), ground-level ozone, and nitrogen dioxide can irritate the respiratory system. Common symptoms include coughing, sore throat, and shortness of breath. People with pre-existing respiratory conditions, like asthma or chronic obstructive pulmonary disease (COPD), are especially sensitive to these pollutants and may experience flare-ups or worsened symptoms.

2. Fatigue and Reduced Mental Clarity

Short-term exposure to elevated indoor CO2 and indoor pollutants such as VOCs can be associated with fatigue, dizziness, headaches, and reduced mental clarity. CO2 itself is usually most useful as a warning sign that ventilationThe process of circulating air to improve indoor air quality. is inadequate for the number of people in a space; controlled studies have also linked ventilationThe process of circulating air to improve indoor air quality., CO2, and VOC conditions with differences in cognitive performance. ³Allen et al. found that cognitive function scores in office workers were associated with carbon dioxide, ventilationThe process of circulating air to improve indoor air quality., and VOC exposure conditions in a controlled exposure study. Allen JG et al., Environmental Health Perspectives, PMID: 26502459, https://pubmed.ncbi.nlm.nih.gov/26502459/.

3. Allergic Reactions and Eye, Nose, and Throat Irritation

Pollutants like pollen, mold spores, and pet dander are common indoor allergens that worsen in poorly ventilated environments. When these allergens accumulate in indoor spaces, they can trigger allergic reactions, leading to itchy eyes, runny noses, and other symptoms. Even for those without allergies, pollutants like dust or VOCs from household products can irritate the eyes, nose, and throat, making indoor air quality crucial for comfort and health.

Long-Term Health Effects of Poor Air Quality

While short-term effects are concerning, long-term exposure to poor air quality has even more serious consequences. Prolonged exposure to pollutants and elevated CO₂ levels can increase the risk of chronic diseases, developmental issues, and even early mortality. Here’s how long-term exposure affects health:

1. Increased Risk of Respiratory and Cardiovascular Diseases

Long-term exposure to pollutants like PM2.5 and ground-level ozone has been strongly linked to chronic respiratory and cardiovascular diseases. Tiny particles from vehicle exhaust, industrial emissions, and wildfires can penetrate deep into the lungs and may enter the bloodstream, contributing to heart disease, stroke, chronic respiratory disease, asthma exacerbations, and lung cancer risk. ⁴WHO identifies PM2.5, ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide as major outdoor air pollutants, and links fine particulate matter exposure to cardiovascular and respiratory disease and cancers. WHO, “Ambient (outdoor) air pollution,” https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health.

2. Cognitive Decline and Neurological Disorders

Research increasingly links long-term air pollution exposure with cognitive health concerns. Chronic exposure to fine particulate matter has been associated with cognitive decline and dementia risk, although researchers continue to study mechanisms and the strength of causal pathways. ⁵A 2023 BMJ systematic review and meta-analysis found evidence of an association between long-term ambient air pollution and clinical dementia, particularly for PM2.5. Wilker EH et al., BMJ, PMID: 37019461, https://pubmed.ncbi.nlm.nih.gov/37019461/.

3. Developmental and Health Risks in Children

Children are especially vulnerable to the effects of poor air quality. Exposure to high levels of air pollution during childhood can impair lung development and increase respiratory risks later in life. Evidence also links some air pollution exposures with neurodevelopmental and asthma-related outcomes, although claims about specific outcomes such as IQ should be tied to the underlying study design and exposure. ⁶Gauderman et al. found that long-term improvements in air quality in Southern California were associated with statistically and clinically significant improvements in lung-function growth in children. Gauderman WJ et al., New England Journal of Medicine, https://doi.org/10.1056/NEJMoa1414123.

How Climate Change is Worsening Air Quality

Climate change is already affecting the air we breathe by increasing conditions that can worsen wildfire smoke, ozone formation, pollen exposure, and indoor air quality challenges. Here is how climate change is impacting the air we breathe:

1. Rising CO₂ Levels

Atmospheric CO₂ concentrations are at the highest levels in human history, and they continue to rise due to the burning of fossil fuels, deforestation, and other human activities. While CO₂ is a natural component of the air, excessive amounts have detrimental effects. Higher CO₂ levels are not only contributing to global warming but also affecting indoor air quality, particularly in poorly ventilated spaces where CO₂ levels can build up and lead to headaches, reduced cognitive function, and respiratory discomfort.

2. Increased Frequency of Wildfires

As temperatures rise and droughts become more frequent, wildfires are occurring with greater intensity and duration. Wildfires release large amounts of particulate matter and carbon monoxide, which can travel hundreds or even thousands of miles, impacting air quality far beyond the fire zones. In recent years, wildfire smoke has severely affected air quality across North America, Australia, and parts of Europe, creating hazardous conditions that have led to widespread respiratory issues and other health problems.

3. Rising Ground-Level Ozone

Ozone at ground level is a harmful pollutant, different from the protective ozone layer in the upper atmosphere. Ground-level ozone forms when pollutants from cars, factories, and other sources react in sunlight. Warmer temperatures accelerate this reaction, leading to higher ozone levels, especially in urban areas. Exposure to high levels of ozone can cause respiratory issues, including asthma attacks and lung damage, especially in children and older adults.

4. Increased Pollen Production

Climate change is also causing plants to produce more pollen and extend the pollen season. Higher levels of CO₂ and warmer temperatures stimulate plant growth, resulting in increased pollen from sources like ragweed, which triggers seasonal allergies. Pollen can also combine with other air pollutants, amplifying allergic reactions and respiratory issues, further worsening air quality.

The Importance of Indoor Air Quality (IAQ)

With people spending about 90% of their time indoors, indoor air quality is a growing concern. Many indoor spaces, like offices, homes, and schools, lack adequate ventilationThe process of circulating air to improve indoor air quality., which can lead to a buildup of pollutants and CO₂. Common indoor pollutants include:

• VOCs: Emitted from products like paints, cleaning supplies, and furniture, VOCs can irritate the respiratory system and contribute to headaches and nausea.
• Radon: A naturally occurring radioactive gas that can seep into buildings, radon is a known carcinogen and is particularly dangerous in poorly ventilated spaces.
• CO₂: High indoor CO₂ levels can cause drowsiness, fatigue, and reduced concentration, particularly in closed spaces where air isn’t circulated effectively.

As climate change worsens outdoor air quality, people may spend more time indoors to avoid pollution, placing even more importance on maintaining good indoor air quality.

Taking Action: How to Protect Your Health

The effects of poor air quality can be managed with individual actions and systemic change. Here are a few ways to protect yourself:

1. Monitor Air Quality: Check air quality indexes (AQIs) in your area, especially on days with high pollution or during wildfire season. Apps like AirVisual and government websites provide real-time air quality data, which can help you make informed decisions about outdoor activities.
2. Improve Indoor VentilationThe process of circulating air to improve indoor air quality.: Proper ventilationThe process of circulating air to improve indoor air quality. is essential for reducing indoor air pollutants. Opening windows, using fans, and investing in air purifiersDevices designed to remove contaminants from the air to improve quality. with HEPA filters can help reduce the concentration of indoor pollutants.
3. Support Clean Energy and Climate Action: Addressing climate change is essential for long-term air quality improvement. Supporting policies that promote renewable energy, reduce greenhouse gas emissions, and protect forests can help mitigate climate-related air quality issues.
4. Use Masks and Air Filters During Poor Air Quality Days: When outdoor air quality is poor due to pollution or wildfire smoke, wearing a high-quality mask (like an N95) can help protect your respiratory system. Indoors, consider using air purifiersDevices designed to remove contaminants from the air to improve quality. to filter out pollutants.

Conclusion: Clean Air is Essential for Health and Well-Being

As our climate continues to change, poor air quality will likely become an increasing threat to public health. The short- and long-term effects of poor air quality are profound, impacting respiratory health, cognitive function, and even developmental health in children. The rising CO₂ levels, combined with the frequency of wildfires, increased ground-level ozone, and extended pollen seasons, paint a concerning picture of the future of air quality.

Clean airAir free of pollutants, including viruses, bacteria, and harmful particles. is a fundamental component of a healthy environment. Recognizing the risks associated with poor air quality and taking proactive steps to reduce pollution, improve ventilationThe process of circulating air to improve indoor air quality., and support climate action can help us protect our health and quality of life. Ensuring that everyone has access to clean airAir free of pollutants, including viruses, bacteria, and harmful particles. should be a priority for all of us,as individuals, communities, and as a global society.