The hot summer months of June, July and August provide many opportunities for individuals and families to engage in outdoor physical activities. Whether its swimming, kayaking, hiking, bike riding, running or walking, people are moving their workout routines outdoors to get a change of scenery and take in the fresh summer air. Yet, for individuals who live in cities and low-income communities plagued by air pollution, poor air quality can be a salient barrier to outdoor exercise. Emissions from cars, trucks, industry and power plants all contribute to poor outdoor air quality. In some communities, smoke from wildfires can also be a concern. Common outdoor air pollutants include particulate matter and gases such as ozone, sulfur dioxide and nitrogen dioxide. Ozone in particular is in greater concentration during the summer months, due to longer days, stagnant air, more sunlight and ultraviolet radiation. These factors contribute to poorer outdoor air quality and potential health hazards related to inhaling polluted air.

Research findings generally support that the health benefits of being physically active outweigh the consequences of breathing in low quality air. The ACSM American Fitness Index suggests the following: exercising earlier in the day, avoiding outdoor activity during peak commuting time and moving your exercise routine indoors to reduce the potential risks associated with exercising outdoors when outdoor pollution levels are high. While the home environment may appear to be a healthier alternative to exercise, home air quality is influenced by outdoor air pollution and indoor sources, such as tobacco smoke, household chemicals and allergens. Nearly six million households harbor moderate to severe environmental hazards, such as lead, tobacco smoke, asbestos and volatile organic compounds. Hence, it is important to consider the specific circumstances of local outdoor and indoor air quality when choosing the best location for physical activity. 

Inequities in environmental exposures

Communities of color and low-income households are more likely to be exposed to poor air quality due to neighborhoods that are often near industrial facilities or freeways and higher rates of poor housing infrastructure. These environmental inequities are due, in part, to unjust policies and urban planning practices that have exacerbated poverty and exposed disadvantaged communities to higher levels of environmental hazards and wastes. Individuals who live in apartments or subsidized housing are particularly vulnerable, as they have decreased opportunity for source control of many pollutants and emissions in their buildings (e.g., existence of lead, mold, gas stoves, poor ventilation). Children, the elderly and individuals with disabilities also represent vulnerable groups, as they are more likely to depend on others to ensure the air quality in their indoor living spaces. Individuals with compromised immune systems may be more susceptible to the harmful effects of pollutants, mold spores and certain bacteria. The combined effects of outdoor and indoor air pollution are one factor contributing to the higher rates of premature death observed in these populations, largely as a result of increased mortality from stroke, heart disease, chronic obstructive pulmonary disease and acute respiratory infections. Given the current COVID-19 pandemic, during which people are more likely to be spending more time indoors, including for exercise, there is a timely need for a heightened focus on improving indoor air quality and offering recommendations to reduce air pollutants in the home.

Recommendations for individuals and families to improve indoor air quality in the home

When exercising indoors, it is important to be aware of indoor pollutants and ways to reduce the particles and toxins in your home.

1. Reduce sources of poor air quality. The most important step to improving air quality is to not allow smoking or vaping indoors. Similarly, avoid other sources of indoor combustion such as open fireplaces, scented candles and burning incense, as these increase particle pollutants. When choosing cleaning products, opt for unscented versions, avoid volatile organic chemicals and limit use of aerosol sprays and air fresheners. When dusting, use a damp or clinging cloth rather than a dry one to capture more dust and dirt. Fix any water leaks in plumbing, roofing or around windows to help prevent mold growth. People with environmental allergies, can also address sources of allergens, such as dust mites, pet dander, mold spores or cockroaches. Avoid exercising indoors immediately after cleaning, as some household cleaning products and activities may temporarily reduce air quality. 
2. Ensure adequate ventilation and air filtration. Cooking can be a big source of air pollutants. If available, use range hoods that vent outdoors in the kitchen when cooking. Homes with forced air heating and/or cooling should use a medium-to-high efficiency filter and change it regularly. If your house or apartment does not have central forced air heating/cooling, consider investing in a portable air cleaner (that does not emit ozone) in the home to reduce particulate pollution. If outdoor air quality is good and there are no concerns for allergies, consider opening windows to ventilate your indoor space. During activities that generate moisture, such as showering or dish washing, maintain adequate ventilation to decrease mold formation.
3. Reduce the entry of outdoor pollutants into the home by adding activities like wiping your shoes or taking them off by the entrance. Keep windows closed during high pollen days and periods of high air pollution to reduce exposure to particulates and petroleum fumes. For those who live near busy roads or highways, keep windows shut during rush hour, particularly when you are exercising. When deciding whether to exercise indoors or outdoors, check daily weather reports via news apps, or visit AirNow.gov. You can also sign up for air quality alerts with EnviroFlash.info.  Finally, check the Environmental Protection Agency’s Air Quality Index  in your city for information on your local pollutant levels and advocate for legislative mandates and comprehensive reporting about outdoor air quality, especially at the neighborhood level.
4. Check your home for safety issues regularly. If you live in a house built before 1978, consider testing your home for lead exposure. Radon, a naturally occurring radioactive gas, can also have a negative impact on indoor air quality. Contact the National Lead Information Center and your state and local radon programs for more information on how to obtain lead and radon test kits. Finally, install smoke and carbon monoxide alarms, and check the batteries routinely.

Using an environmental justice approach to equitably ensure indoor air quality.

Environmental health research shows that not all spaces are created equal. Urban development and policies have disproportionately exposed disadvantaged communities to higher levels of harmful pollutants that affect both indoor and outdoor air quality. Poor indoor air quality is an environmental justice issue, and it is essential to advocate for patients and clients who are most vulnerable to air pollutants to reduce health disparities and promote active living.

Local governments, health care systems and neighborhood groups have a role in educating people about local environmental exposures, with special outreach to residents of high-exposure areas. To address inequities, however, a collective approach is needed to remove sources of indoor and outdoor pollutants concentrated in disadvantaged communities. Partnerships among grassroots organizations, environmental health agencies and public health professionals are needed to advocate for laws, regulations and policies that promote environmental justice and protect vulnerable communities.

While ACSM actively encourages individuals and families to engage in daily exercise, we recognize that not all persons have access to high quality air. We also acknowledge that clean air, both indoors and outdoors, is a human right and inequities in air quality contribute to disparities in physical activity participation and disease morbidity and mortality. Yet, there are feasible strategies to reduce indoor air pollutants and provide more equitable access to clean air in every household and community. By using an environmental justice approach to advocate for clean air, indoor and outdoor exercise can, once again, become a safe and healthy summertime activity enjoyed by all.