Chicago's Air Quality: Graded

Chicago, Illinois, has a long history of unhealthy air pollution, dating back to the city's industrialization in the late nineteenth century. The city's air quality has been described as moderate by the US Environmental Protection Agency (EPA), with an Air Quality Index (AQI) of 52 in 2019. Northeastern Illinois, where Chicago is located, has been reported to have air pollution levels that do not meet Clean Air Act standards intended to protect human health, particularly in terms of ground-level ozone and fine particulate matter. Chicago's ozone levels have earned it a failing grade from the American Lung Association, and it ranks 16th in the nation for ozone pollution and 22nd for particle pollution. The city's particle pollution is the worst in the state of Illinois and ranks 79th nationally.

Chicago's air quality ranks as 'moderate'

Chicago's air quality has historically been poor, dating back to the city's industrialization in the late nineteenth century. At that time, the burning of dirty coal from southern Illinois to heat buildings, power engines, and run steel mills blanketed the city in a toxic cloud, leading to increased health issues for its residents. While efforts in recent decades have improved air quality, Chicago still faces challenges, particularly with ozone and particulate matter pollution.

According to the IQAir report, in 2019, Chicago had an average Air Quality Index (AQI) of 52, which is considered "moderate" by the US Environmental Protection Agency (EPA). The EPA defines "moderate" air quality as potentially unhealthy for sensitive groups, including children, the elderly, and people with pre-existing cardiovascular or respiratory conditions. This rating is based on the weighted health risks of six key criteria pollutants.

Chicago's air pollution levels can vary, with real-time AQI values ranging from "good" to "unhealthy for sensitive groups." The city's overall AQI, as well as that of specific pollutants like PM2.5 (fine particulate matter) and O3 (ozone), can be monitored in real time through various tools and platforms. These tools provide valuable information for residents, especially those vulnerable to the effects of air pollution.

While Chicago's air quality has shown improvement, it still faces significant challenges. Northeastern Illinois, including Cook County and surrounding areas, has consistently failed to meet National Ambient Air Quality Standards (NAAQS) for ground-level ozone and is expected to fall short in fine particulate matter standards soon. This means that the air pollution levels in these areas are considered unhealthy and pose risks to human health, as outlined in the Clean Air Act.

Ozone, a major pollutant in Chicago, forms when emissions from vehicles, power plants, and fires interact with heat and sunlight. It can irritate the airways and lungs, aggravating respiratory issues like asthma and compromising the body's defence against infections. Additionally, particulate matter, or soot, can lodge deep in the lungs, contributing to lung cancer risk and exacerbating health issues for vulnerable individuals.

Northeastern Illinois does not meet federal health standards

Northeastern Illinois has a long history of unhealthy air pollution, dating back to the city of Chicago's industrialization in the late nineteenth century. At that time, Chicago relied on dirty coal, which produced soot that blanketed the city in a toxic cloud, leading to increased health issues such as pneumonia, asthma, and heart and lung diseases. While there have been efforts to improve air quality over the past few decades, the region still faces challenges in meeting federal health standards.

The air quality in northeastern Illinois, including Chicago, has significant implications for the health and well-being of its residents. The region's air pollution levels do not meet the Clean Air Act standards intended to protect human health, as outlined by the US Environmental Protection Agency (EPA). This nonattainment status indicates that the air pollution levels exceed what is considered safe and healthy for people to breathe.

Ozone and particulate matter are the primary concerns in northeastern Illinois. Ground-level ozone, formed from emissions and reactions with heat and sunlight, can damage the lungs, exacerbate asthma, and impair the body's ability to fight respiratory infections. Fine particulate matter, or PM2.5, is another critical pollutant, with Chicago ranking 79th nationally out of 1517 metropolitan areas for particle pollution in 2019. This fine particle pollution can have serious health impacts, especially for sensitive groups such as children, the elderly, and those with pre-existing health conditions.

The failure to meet federal health standards has consequences beyond the immediate health risks. It may result in the loss of federal funding for transportation projects aimed at reducing emissions and improving air quality. Additionally, it could lead to weakened environmental standards and the rollback of regulations that have helped make progress in improving air quality over the years.

While there have been some improvements in air quality in northeastern Illinois, the region still has work to do to ensure that its residents can breathe cleaner air and mitigate the health risks associated with air pollution. This complex issue requires a multifaceted approach, including continued legislation for cleaner air, investments in transportation projects that reduce emissions, and community support for public transit, biking, walking, and electric vehicles. By addressing these challenges, northeastern Illinois can strive to meet federal health standards and improve the overall well-being of its residents.

Chicago's air pollution history

Chicago has a long history of poor air quality, dating back to the city's industrialization in the late 19th century. During this period, the city relied on dirty coal, which produced soot that covered Chicago in a toxic cloud. This led to an increase in instances of pneumonia, asthma, and heart and lung diseases.

In 1959, Chicago established the Department of Air Pollution Control to investigate and regulate emission sources. Subsequent regulations, including the federal Clean Air Act of 1970 and more recent city and state legislation, have helped mitigate emissions. Despite these efforts, Chicago's air pollution levels have historically been unhealthy. Between 1996 and 1998, there were 28.5 unhealthy ozone days annually, and this number fell to 19.2 unhealthy ozone days per year between 2006 and 2008, a 33% decrease.

In 2019, Chicago's air quality index (AQI) averaged 52, which is considered "moderate." This means that while the air quality is generally acceptable, sensitive groups such as children, the elderly, and people with pre-existing health conditions may experience symptoms from long-term exposure. The main pollutants in Chicago's air are fine particulate matter (PM2.5) and ozone. Chicago's PM2.5 pollution is the worst in the state of Illinois and ranks 79th nationally out of 1517 metropolitan areas in the United States.

While Chicago's air quality has shown a long-term trend of improvement, recent years have seen a worsening trend. Particle pollution has nearly doubled since 2017, and the city's dependence on motor vehicles has led to rising transport emissions, which plague Chicago's air quality.

The impact of air pollution on health

Chicago has a long history of unhealthy air pollution, dating back to the city's industrialization in the late nineteenth century. During this period, Chicago relied on dirty coal to heat buildings, run motor engines, and power steel mills. The soot produced by burning dirty coal covered the city in a dense toxic cloud, increasing instances of pneumonia, asthma, and heart and lung diseases.

In 2019, Chicago averaged an air quality index (AQI) of 52, which is considered "moderate" by the US Environmental Protection Agency (EPA). However, the EPA also notes that moderate air quality can be potentially unhealthy for sensitive groups, including children, the elderly, and people with pre-existing cardiovascular or respiratory health conditions. The overall Chicago AQI as of 2023 is 39, which is an improvement, but the PM2.5 pollution ranks Chicago as the worst in the state of Illinois for particle pollution.

Air pollution is defined as the presence of one or more contaminants in the atmosphere, such as dust, fumes, gas, mist, odour, smoke, or vapour, in quantities that can be harmful to human health. The respiratory tract is the main pathway of exposure, and pollutants can cause inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting the lungs, heart, brain, and other organs. Fine particulate matter, such as PM2.5, is of particular concern as it can penetrate deep into the lungs, enter the bloodstream, and travel to other organs, causing systemic damage to tissues and cells.

The health effects of air pollution are wide-ranging and can impact almost every organ in the body. Short-term exposure to high levels of particulate matter can lead to reduced lung function, respiratory infections, and aggravated asthma. Long-term exposure increases the risk of chronic diseases, including stroke, heart disease, chronic obstructive pulmonary disease, and cancer. Ozone (O3) is another pollutant that can irritate the lungs, causing inflammation and other damage that impacts multiple body systems. Both short-term and long-term exposure to ozone can lead to respiratory problems, even in otherwise healthy young adults.

Certain populations are more vulnerable to the health impacts of air pollution. Children, the elderly, pregnant women, and people with pre-existing health conditions are more susceptible to air pollution-related diseases. Additionally, people of colour are more likely to live in areas with higher pollution levels due to historical redlining practices, and they are also more likely to have chronic conditions that make them more susceptible to the health impacts. Socioeconomic factors, such as poverty and racial discrimination, can also amplify the harmful effects of air pollution.

Efforts to improve air quality

Chicago has a long history of unhealthy air pollution, dating back to the city's industrialization in the late nineteenth century. The city once relied on dirty coal to heat buildings, run motor engines, and power steel mills, and the soot produced by burning this coal had severe health impacts on residents.

Over the last three decades, the United States federal government, the State of Illinois, and the City of Chicago have implemented legislation to improve air quality. The frequency of unhealthy ozone days has fallen 33% between the periods of 1996-1998 and 2006-2008. Despite this, Chicago's air pollution levels remain "unhealthy" by EPA standards, and particle pollution has nearly doubled since 2017.

• Biking for commuting: The city is working to increase the accessibility and attractiveness of biking by maintaining 117 miles of on-street bike lanes.
• Alternative fuels: Chicago is promoting compressed natural gas, E85, propane, and biodiesel fuels as cleaner alternatives to traditional gasoline.
• Diesel Retrofit Program: This program includes new clean diesel requirements.
• Idling reduction of diesel vehicles: The city is limiting diesel trucks to three minutes of idling within a sixty-minute period.
• Electric vehicles: Chicago is providing charging locations for electric vehicle owners and offering incentives for purchasing them.
• Permitting and inspection of high-emitting industries: The city is regulating the construction and expansion of facilities that create air pollution.
• Public transit: The Chicago Metropolitan Agency for Planning (CMAP) is programming federal funding to invest in transportation projects that reduce emissions, such as public transit, cleaner trains, bike paths, and sidewalks.
• The Clean Air Act of 1970: This federal legislation has helped to mitigate city-wide emissions.

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