Asthma is a chronic inflammatory disease that affects the airways. Mild asthma causes inconvenience while severe cases are life-threatening. Common asthma symptoms include shortness of breath, wheezing, coughing, and chest pain. Factors that irritate the airway may trigger asthma attacks. Dust mites, animal dander, mold, second-hand smoke, pollen, cold air, and high humidity are common causes.

In cities, air pollution found in high levels of airborne particles and smog-inducing agents from car exhaust are major asthma inducers. If you suffer from asthma, consider the asthma triggers rampant in these U.S. states:

1. Virginia
AAFA identifies another high asthma rate region spanning from Massachusetts to North Carolina that includes Richmond in central Virginia. The city has high incidents of emergency visits and death caused by the disease. The main trigger is air pollution. Poverty is another reason indirectly causing the high asthma burden in the city.

2. Massachusetts
Springfield ranks number one among all cities that have high asthma cases and Boston follows not too far behind as number eight according to AAFA’s “asthma capital” chart. The main culprit is high pollen levels in the Spring season.

3. Ohio
According to the Asthma and Allergy Foundation of America (AAFA), this state has five cities, Cincinnati, Columbus, Arkon, Cleveland, and Dayton, that are among the top 20 with the highest asthma rates in the entire country. Dayton ranked second. All five cities have high Spring pollen counts, which is one of the main natural asthma triggers. More importantly, they also suffer from low air quality due to the high density of pollution heavy industries.

4. Kentucky
Kentucky, especially the industrial Appalachian region in the eastern part of the state, has a high asthma rate. Louisville is one of the top 20 “asthma capitals” in the country. Like Dayton, the city is built on the Ohio River flood plain and has high Spring pollen counts. Poor air quality due to industrial activities is another major factor to blame. Poverty in this area is also prevalent, which likely adds to poor indoor living conditions and insufficient care to manage the disease.

5. Michigan
According to CDC, the overall asthma rate in Michigan is higher than the US average, especially among the young adult population between 18-24 years old. The Detroit metropolitan area has one of the highest asthma rates in the country due to traffic-caused air pollution. Car exhausts produce smog-forming gases like nitrogen oxide and sulfur dioxide that can directly trigger asthma. Moreover, the greater Detroit area has large low-income populations. They are more likely to live in homes contaminated with indoor asthma triggers like mold and pests, thus exacerbating the problem.

6. Pennsylvania
Pennsylvania also has an above-average asthma rate. Two major cities-Allentown and Philadelphia, ranked the sixth and fourth suffering from high disease burden, respectively. Allentown has poor air quality caused by high levels of ozone. Also, the city has weak laws regulating smoking and has a large number of smokers. To make things worse this area also has a shortage of respiratory specialists to help with disease management. Philadelphia records a high level of asthma-related emergency room visits and death. Air pollution is the main cause since the city also suffers from high ozone and airborne particle pollution caused by motor traffic. High poverty rates in the city also contribute to the prevalence of the disease.