Air quality in Cleveland

How bad is Cleveland air pollution?

Cleveland air quality fails to meet U.S. Environmental Protection Agency (EPA) standards for ozone and PM2.5. Its non-attainment status for these air pollutants positions the city as one of the most polluted cities in the United States, ranking:¹

• #31 for high ozone days out of 226 U.S. metropolitan areas
• #14 for annual particle pollution out of 199 U.S. metropolitan areas

Ozone

Between the 2017-2019 three-year monitoring period, 18 days exceeded EPA daily ozone targets, a number far higher than the federal 3.2 day standard. Cleveland ozone levels have steadily worsened since the 2013-2015 period, when the city almost reached attainment with a total of 3.5 unhealthy days during that period.

PM2.5

In 2020, Cleveland averaged a PM2.5 concentration of 12.4 µg/m³ (“moderate”), failing to meet the U.S. EPA standard set at < 12.0 µg/m³ (“good”) as well as the more stringent World Health Organization (WHO) standard of < 10.0 µg/m³. During 2020, Cleveland ranked as the most polluted city in the state of Ohio out of 28 cities. No other cities in Ohio breached the U.S. EPA standard for “good.”

Other cities with significant air pollution in Ohio include:

• Seville air quality: 10.0 µg/m³
• Wadsworth air quality: 9.9 µg/m³
• Norton air quality: 9.8 µg/m³
• Lewis Center air quality: 9.7 µg/m³

Why is Cleveland’s air polluted?

While many cities in the United States have experienced major improvements in their local air quality since the initial implementation of the Clean Air Act in 1970, residents of Cleveland continue to be exposed to poor air quality deemed unsafe by the U.S. EPA.

Situated on the southern side of Lake Erie, one of the five great lakes in North America, Cleveland has a long history as a prominent manufacturing hub for the Midwestern United States. Its historic location along numerous transportation routes and near large coal and iron ore deposits has helped rapidly develop and sustain the city’s economy, but often at the cost of poor air quality.²

Today, advanced manufacturing, metal production and fabrication, and automotive facilities remain prominent industries, contributing to city-wide emissions.³ However, the city has tightened emission limits on these industries, reducing air pollution levels by nearly 75% since monitoring began in 1990. Moreover, Cleveland has made pushes to diversify its industries toward other areas, such as biotechnology and information technology, while abandoning many of its polluting energy plants.

Ohio’s oil and gas industry, however, remains problematic. As a state, Ohio produces more than 4.2 billion cubic feet of natural gas per day (a sevenfold increase since 2014). Tens of billions of dollars have been invested since 2010 to build the industry further, an investment that may further exacerbate Cleveland’s troubles in reaching federal attainment levels for air pollution.

Other prominent emission sources include:⁴

• the use of motor vehicles by over 385,000 residents
• diesel-powered commercial trucks and trains
• factories and power plants that use fossil fuels like coal and gas for energy
• construction sites and road repairs

When is Cleveland air pollution the highest?

Cleveland tends to experience periods of elevated PM2.5 air pollution in both the summer and winter. In 2020, Cleveland’s most polluted months for were:

• December: 18.1 µg/m³
• November: 15.0 µg/m³
• July: 13.7 µg/m³
• June: 13.2 µg/m³
• February: 13.2 µg/m³

In the winter, Cleveland’s elevated PM2.5 levels are attributable to:

• cars idling while defrosting
• winter wood-burning for domestic heating and ambiance
• increased electricity consumption as a result of darker, colder evenings
• weather conditions—namely, cool air inversions—that can trap air pollution in the lower atmosphere, causing air pollution to accumulate to high levels

In the summer, elevated PM2.5 levels are typically attributed to:

• resuspended dust from increased construction
• wildfires
• softer wind currents and stagnant air
• less frequent precipitation

What are the main pollutants in the air in Cleveland?

The U.S. EPA monitors six key air pollutants in real time, including:

• particulate matter (both fine particles (PM2.5) and coarse particles (PM10)
• ground-level ozone, the primary ingredient in smog
• carbon monoxide (CO)
• nitrogen dioxide (NO₂)
• sulfur dioxide (SO₂)

In Cleveland, PM2.5 (fine particulate matter) and ozone are of greatest health concern. The city has failed to meet EPA attainment standards for both of these main pollutants.

PM2.5

PM2.5, or fine particle pollution, is a mixture of solid and liquid droplets in the air with a range of chemical makeups. Despite samples containing a range of chemical compositions, PM2.5 is commonly understood to be the most harmful air pollutant for its defining characteristic — its small size.

PM2.5 is so small that it can pass through the airways and lungs and become absorbed into the bloodstream upon inhalation. Once in the blood, PM2.5 has the potential to cause far-reaching health impacts beyond the heart and lungs, reaching nearly every organ in the body.

Sources of PM2.5 in Cleveland include:

• motor vehicle emissions
• wind-blown dust, dirt, and pesticides from agricultural areas
• resuspended dust at construction and road repair sites
• power plants
• factories
• boats and ships on Lake Erie
• diesel exhaust from construction equipment, trucks, and trains

Ozone

Ground-level ozone is a noxious gas pollutant formed in the atmosphere rather than being emitted directly by ground sources. For an ozone-producing chemical reaction to occur, ambient nitrogen dioxide (NO₂) and volatile organic compounds (VOCs) must be in the presence of sunlight and heat (generally temperatures above 84°F). This means that ozone typically exists at higher levels during the summer months.

Cleveland experiences an average of 66 days a year above 80°F and 9 days a year over 90°F.⁵ These days predominantly occur between June and September, indicating that ozone is more likely to reach unhealthy levels during these months.

Who is most vulnerable to air pollution in Cleveland?

No one is immune to the damaging effects of air pollution exposure. However, certain groups are more likely to experience acute adverse effects. These groups include children, the elderly, those with compromised immune systems or preexisting health conditions, and pregnant mothers.

In Cleveland, the number of residents living with sensitivities includes:

• Children under 18: 254,117
• Adults over 65: 230,202
• Pre-existing health conditions:
• Asthma: 128,588
• COPD: 88,818
• Lung cancer: 799
• Cardiovascular disease: 100,971

Everyone, but vulnerable groups in particular, should take care to reduce their air pollution intake or exposure. Measures that can help to reduce the risk of adverse health effects from pollution include:

• wearing fine particle-filtering face masks, such as N95/KN95/FFP2 masks
• avoiding outdoor activities during periods of heavy air pollution
• sealing indoor spaces by closing outdoor-facing doors and windows and running indoor air filters or purifiers when available

+ Article Resources

[1] American Lung Association. (2020). State of the air – 2020.
[2] Ohio History Central. (2021). History - Cleveland, Ohio.
[3] Team Neo. (retrieved 2021). Northeast Ohio - key industries.
[4] Reardon K. (2019, May 19). Where's the worst air pollution in Ohio? And where does global warming fit in? Cleveland.com
[5] Current Results. (2020). Cleveland temperatures: averages by month.