There isn’t just one reason why some people get asthma. Several risk factors can make someone more likely to get asthma – such as heredity, exposure to tobacco smoke or harsh chemicals, or an illness. Other factors can add to that risk as well. And many of these factors depend on where a person lives.
AAFA's Asthma Capitals™ Report ranks the largest 100 U.S. metropolitan cities by how challenging they are to live in with asthma. AAFA publishes this report to help people who live in Asthma Capitals advocate for better care and policies. The report also shows how communities can best direct their focus to reduce the impact of asthma.
This report’s ranking is based on weighted outcomes: asthma prevalence, asthma-related emergency department visits, and asthma-related deaths.
The report also analyzes eight risk factors that can influence asthma outcomes: poverty, lack of health insurance, air pollution, pollen count, long-term controller medicine use, quick-relief medicine use, smoke-free laws, and access to asthma specialists.
Our report looks at how challenging it is to live with asthma in the top 100 U.S. continental cities. Download our full report to see where each city ranks for asthma outcomes (prevalence, asthma-related emergency room visits, and mortality). The report also reviews eight risk factors that impact asthma.
Many people in Greensboro frequent the emergency room for their asthma, placing this Southern city in the #20 spot. Risk factors impacting these health outcomes include the city’s 16% poverty rate and few smoking laws. These factors all reveal that many of the people with asthma in the area aren’t getting the proper treatment to keep their asthma under control.
Fresno has high rates of asthma-related emergency room visits and deaths, leading to its #19 place in this year’s Asthma Capitals report. High pollen rates and poor air quality can make it harder to manage asthma in the area – Fresno County scored an F for high ozone and particle pollution in the American Lung Association’s State of the Air report. These factors, as well as high rates of quick-relief medicine use, contribute to Fresno’s ranking.
Boston’s asthma prevalence and asthma-related rates for emergency room visits are average, yet it is still one of the highest on our list for asthma-related deaths. Like other cities on our report, poverty is a risk factor for Boston, with 16.7% of the city’s population living below the federal poverty level.
One of the oldest cities in America is also one of the most challenging places to live with asthma, as seen by its high asthma prevalence and asthma-related emergency department visits. Hartford’s residents with asthma face high pollen. Pollen can trigger asthma symptoms in people with allergic asthma. Even though Hartford is #17 overall on our Asthma Capitals report, it ties with New Haven, Connecticut, and Springfield, Massachusetts, for high estimates of people affected by pollen.
Louisville ranks high on our list due to its high rates of asthma-related emergency room visits. Though poor air quality previously contributed to Louisville’s ranking, ozone levels and particle pollution have improved in recent years. Through a program run by AIR Louisville, they use GPS health sensors attached to inhalers to track medicine use and find ways to improve air quality. However, the city continues to have high rates of long-term controller and quick-relief medicine use.
Nicknamed “Motor City” for its history at the heart of the automotive industry, Detroit is our #15 Asthma Capital due to its high rates of asthma prevalence and asthma-related deaths. As with other cities in the top 20, high poverty rates and poor air quality are risk factors for Detroit. These factors likely contribute to the city’s high rates of quick-relief medicine use, another risk factor that is linked to poor asthma control.
High asthma prevalence and high rates of asthma-related deaths land Birmingham in our top 20 Asthma Capitals for 2021. The city’s 16.2% poverty rate contributes to these outcomes. Birmingham also has few smoking laws preventing exposure to secondhand smoke.
Columbus joins three other Ohio cities in the top 20 and is part of the Ohio Valley “Asthma Belt.” It’s high on the list for higher-than-average emergency room visits. Columbus also has higher-than-average scores for quick-relief and long-term controller medicine use.
Previously our #1 Asthma Capital in 2019, Springfield remains in our top 20 for 2021. The city still ranks high in asthma-related emergency room visits, securing its #12 spot in our list. High pollen scores can make asthma worse for people living in Springfield – the city ties with Bridgeport, Hartford, and New Haven for having the second-highest annual pollen scores in the country. Pollen may also contribute to the city’s high rates of quick-relief medicine use.
Worcester joins Springfield and Boston as one of three Massachusetts cities in our top 20 Asthma Capitals. Worcester has high rates of asthma-related emergency room visits and asthma-related deaths. Though it has some of the lowest poverty and uninsured rates in the country, people living in the area may still find it difficult to keep their asthma under control, as quick-relief medicine use in Worcester is particularly high.
Tucson lands in the top 10 of this year’s Asthma Capitals due to its high rate of asthma-related deaths. In fact, Tucson has the fifth-highest asthma mortality rate in the country. Poor air quality and high levels of pollen in the spring may contribute to these outcomes.
Oklahoma City is this year’s #9 Asthma Capital due to its high scores for asthma prevalence and asthma-related deaths. The city also has higher-than average scores for four risk factors: poverty rates, uninsured rates, annual pollen scores, and long-term controller medicine use. The city also has few smoking laws. This increases exposure to secondhand smoke, a common trigger for asthma.
Dayton is the sixth largest city in Ohio, but it ranks the highest of the Ohio cities on our list at #8. The “Birthplace of Aviation” has the third-highest rate of emergency room visits due to asthma. High poverty rates and pollen scores contribute to these outcomes, as well as Dayton’s high rates of quick-relief and long-term controller medicine use.
The sixth largest city in the U.S. is our #7 Asthma Capital because of a high number of emergency room visits and a high number of asthma fatalities. Considered one of the nation’s poorest cities, poverty is no doubt the top risk factor in Philadelphia’s asthma rates. Like other cities in the top 20, Philadelphia also has high rates of quick-relief medicine use, another risk factor that contributes to health outcomes.
With a higher-than-average rate of asthma-related emergency room visits and asthma-related deaths, Cleveland lands at #6. With a high poverty rate of 16.2% combined with high levels of ozone, it’s not surprising 9% of Cleveland’s residents have asthma. Cleveland also has the sixth highest rate of quick-relief medicine use, showing that many residents may have uncontrolled asthma.
This coastal city in Connecticut comes in at #5 because of its high rates for asthma prevalence, emergency room visits due to asthma, and asthma-related deaths. New Haven’s residents have high usage of both long-term control and quick-relief asthma medicines. This is connected to very high pollen counts in both spring and fall.
This Midwestern city on the shore of Lake Michigan made our list for a high number of asthma-related emergency room visits and asthma-related deaths. In fact, Milwaukee has the second-highest rate of emergency room visits due to asthma. This is likely related to its 16.9% poverty rate. Many residents also have high rates of quick-relief medicine use.
Richmond is #3 on our Asthma Capitals list for high asthma-related death and emergency room visits. The city’s high poverty rate is a factor. Low-income families may face poorly maintained rental housing, urban locations with high pollution, and lack of resources to pay for proper care. Richmond also has the highest annual pollen score, which can make asthma worse for people with allergic asthma living in the area.
The birthplace of “The Star-Spangled Banner” is also home to high asthma-related emergency room visits and asthma-related deaths. The city’s high poverty rate is the leading contributing risk factor. According to the Centers for Disease Control and Prevention (CDC), people living below the poverty level are more likely to have asthma than those above it.
Allentown is first on our list as the top Asthma Capital of 2021 due to its high rates of asthma-related emergency room visits. Risk factors affecting these asthma outcomes include a high estimate of people affected by pollen and few smoking laws.
The COVID-19 pandemic impacted daily life in most of 2020. The pandemic influenced some changes in health outcomes and risk factors like pollen exposure, medicine use, and emergency room visits. In 2020, fewer people experienced pollen allergies due to COVID-19 restrictions, recommendations to stay indoors, and other preventative measures like mask wearing. As a result, use of long-term asthma medicines were also down along with fewer people heading to hospital emergency rooms for asthma.
This report also examines regional trends found in the two “Asthma Belts” – the Ohio Valley area and the Northeast Mid-Atlantic region – and the impact of human activity and climate change in the west.
(Alaska, Hawaii, Puerto Rico, and tribal nations were not factored into this report due to a lack of data on asthma in these populations.)
Northeast Mid-Atlantic Asthma Belt
This cluster extends from Massachusetts to North Carolina. Poverty, air pollution, and access to specialists are key risk factors for these cities. This is likely due to more industrial and urban populations. Asthma rates tend to be higher, especially among children, in urban locations.
This year’s top Asthma Capital is Allentown, Pennsylvania, the mid-way point in the Northeast Mid-Atlantic Asthma Belt. Allentown’s placement in the top spot is largely due to high rates of asthma-related emergency room visits. Compared to previous years, Allentown's asthma emergency room rate has been increasing steadily.
Ohio Valley Asthma Belt
Three Ohio cities are in the top 20 of our report – Cleveland, Dayton, and Columbus. Nearby, Detroit, Michigan, and Louisville, Kentucky, appear in this “Asthma Belt.” With so much of this region facing poor outcomes, asthma appears to be a widespread concern. Poverty, air pollution, and high numbers of medicine use are the key risk factors that have placed these cities at the top of our report.
Asthma in the West
Two western cities are now in the top 20 − Tucson, Arizona (#10), and Fresno, California (#19). There has been an increase in wildfires and air pollution in the west. In 2020, both cities had high rates of asthma-related deaths, and Fresno had high rates of asthma-related emergency room visits. High pollen levels and poor air quality contributed to these outcomes.
Reduced asthma rates and deaths are possible. This report shows where we can focus our efforts for healthier environments and communities. Researchers, health care providers, federal and state policy makers, and local stakeholders all must work together to improve local communities and make asthma care more widely available. View our report to see specific actions that can be taken to help the more than 25 million Americans with asthma.
The 2021 Asthma Capitals™ report is an independent research project of the Asthma and Allergy Foundation of America made possible in part by support from the Pharmaceutical Care Management Association (PCMA) Foundation.