Air Pollution: AQI and US Pollution

Air Pollution: AQI Description and Current US Map Example:

By Joseph Kauffman

The AQI stands for Air Quality Index and refers to the EPA’s index for reporting daily air quality. It ranges on a scale from 0 to 500 and can be broken down into 6 categories. Where 0 to 50 is considered good air quality (green), 51 to 100 is moderate air quality (yellow), 101 to 150 is unhealthy for sensitive groups (orange), 151 to 200 is unhealthy for all groups (red), 201 to 300 is very unhealthy (purple), and 300+ is hazardous to human health (maroon). The AQI focuses on a group of particulate matter and gases that are prevalent in our atmosphere and the most responsible for adverse health effects in terms of respiratory issues. These particles include Carbon Dioxide, Sulfur Dioxide, Particulate matter, Ozone, and a few nitrogen Dioxides. Particulate matter can be broken into two main categories based on their size and how deep within the lungs the particles will fall. Coarse Fraction refers to particulate matter between 2.5 and 10 μm, which refers to PM that can typically be seen with the naked eye and is known to accumulate in the upper respiratory airways. Fine fraction refers to any PM smaller than 2.5 μm and is linked to more adverse health effects, as these particles can accumulate very deep in the lungs. There is also a 3rd lesser-known category of PM, which is defined as any particulate matter less than 0.1, and is very concerning for human health because these particles are so small that they can enter the bloodstream and cause a copious amount of problems. The main idea of PM is that the smaller the particle, the more potential harm it can cause within the human body. As these particles get smaller and smaller, the more easily they can diffuse into the major organs, blood vessels, and other structures within the body and cause health problems. (JNK)

After referring to a current map (as of 3/08/25) of the AQI in the US provided by the EPA’s official website, the biggest problem areas include the area surrounding the El Paso, New Mexico area and the majority of the center of the country including, but not limited to, the states of Texas, Oklahoma, Missouri, Iowa, and Wisconsin. Poor air quality can be caused by environmental or anthropogenic sources or even a mixture of both. Environmental sources include, but aren’t limited to, wildfires, dust storms, and volcanic eruptions. On the other hand, anthropogenic sources can include vehicle exhaust, burning of organic/inorganic material, and industrial production. In El Paso, New Mexico, the poor AQI quality is a good example of this mixture of sources. On the environmental side, El Paso is currently facing a drought that they have not seen since the mid-1930s, and as a result, they have seen increased amounts of dust being kicked up into the air. El Paso is also facing irregularly strong wind patterns that have also been mixing dust into the air and causing increased rates of particulate matter in the surrounding atmosphere. However, environmental sources are not the only ones at fault in this situation. According to Diego Mendoza-Moyers of El Paso Matters, anthropogenic sources of pollution in the area can be attributed to the long lines of people trying to enter/leave the country along the border. The accumulation of these idling vehicles has compromised the atmosphere in the area, and these vehicles are also responsible for kicking up dust as they drive, and when mixed with the exhaust fumes, can make for an unpleasant fusion of PM in the lungs. However, PM is only really a concern for sensitive populations like children, the elderly, and respiratory-compromised individuals. The health effects can still be adverse for those of the healthy and working populations if the AQI increases above 151. Once it reaches this level, any people in the area will begin to suffer respiratory issues that are still underresearched. Meaning the severity of these adverse health effects could be anywhere from minor to severe. (JNK)

In other parts of the US, poor air quality can be attributed to other, more natural sources. In states like California, some of their poor air quality can be attributed to the environmental structure that surrounds cities like Los Angeles, more commonly known as the San Gabriel and San Bernardino mountain ranges. This natural phenomenon is referred to as Temperature inversion, and it is the process in which the development of especially strong temperature inversions occurs, especially during the summer months. These inversions inhibit vertical air mixing, which decreases visibility and traps pollutants close to the ground. Increasing the risk of adverse health effects in sensitive populations. These temperature inversions prevent pollutants from escaping the metropolitan area basins. Although this problem has caused major problems for Southern California in the past, the above-average rate of Santa Ana winds this year has mitigated the temperature inversion problem for the LA area. However, these winds are not going to be as active or reliable for mitigation in the future. So this temperature inversion problem is still going to be a huge, recurring problem for the people of Southern California. Since this is a natural phenomenon that is caused by the natural structure of the landscape around southern California, there is little to be done to prevent it from occurring. Some things that could help reduce the magnitude of this problem could be to promote the use of public transportation to take more cars off the road. This will help reduce exhaust fumes in the area. Other strategies that could be implemented include just driving less in general and planting trees and shrubs where it’s plausible to promote airflow. Promoting walking when able to will also lower the effects of temperature inversion. (JNK)

Other major sources of Air pollution in the US currently are wildfires. These wildfires continue to rage across the east and west coasts of the U.S., as the devastation grows unchecked and widespread. A majority of the centermost states in the US have become trapped between the wildfires on either side and have suffered in terms of air quality. The long-term effects of this are undetermined, however, the elderly, infants/children, and those with a compromised respiratory system may suffer from adverse health effects if the air quality continues trending downward in this manner. Wildfires in California and the Carolinas continue to burn to this day. Although efforts have been extensive in terms of clean-up and restoration, the health effects resulting from the poor air quality of these wildfires will need to be further monitored to assess the true extent of damage caused to the general public. Both in the states of those current wildfires and those hundreds of miles away. The air quality problem doesn’t slow down over the ocean either. As the Santa Ana winds continue to blow LA smog into the sea, on the other side of the US. The same instances occur in the Carolina wildfires, where ash and soot are carried out into the open ocean and dumped via precipitation. This can cause ecosystem damage to the fragile coral reefs and other ocean organisms. (JNK)

After performing a statistical analysis, the American Lung Association found that every 4 in 10 Americans are living with unhealthy air in 2024. This totals out to about 131.2 million Americans and is 11.7 million more people than in 2023. This increase in poor air quality can be attributed to the long chain of extreme heat, drought, and wildfires that have taken place in the last few years. These sources of pollution have been especially bad for those living in the Western US. However, the EPA has changed its “healthy air” standards to make them a little stricter. So the increase in individuals being in bad air can be attributed to this as well. The EPA uses a standard called the “State of the Air”, and this report mainly focuses on two air pollution sources. Those sources are fine particles or PM, and Ozone. However, this report isn’t all negative; this report has been in place since 2000 and has monitored air quality policy success stories like the Clean Air Act. This has moderately reduced the percentage of poor air quality in the country. Of the 119 counties in the US that have received a “failing grade” based on the standards of this program. A majority of them are located in the western US. Bakersfield, California, topped this list for the 5th year in a row. The air in Bakersfield was ranked the worst level of year-round particle pollution for 5 straight years in a row. Other cities that remain at the top of this list include Los Angeles and a few other Southern California. However, the problem isn’t only concentrated in California counties. More than 90.7 million Americans are living in counties with failing grades for year-round particulate pollution. 5 of the 26 most polluted cities in the US experienced their worst-ever levels of year-round particle pollution. These cities include Yakima, Washington, which has remained at the same level for its 3rd consecutive year, others include Sacramento, California; Reno, Nevada; Eugene, Oregon; and Spokane, Washington. California has not done well in the last few years on this test, and 2024 was no exception. Of the 25 worst air-polluted cities in the US, 8 of them are located in California, and Los Angeles experienced one of its worst year-round particle pollution ever. In light of all the bad trends on the West Coast, Birmingham, Alabama, made an incredible recovery between 2023 and 2024, jumping from the 18th worst in the country to the 96th. Highlighting that not all cities are only getting worse. I mentioned before that the EPA tightened up on some of its limits and its standards of “good air quality”. This makes Birmingham’s success story even more impressive and should be taken into account while other cities continue to try to clean up their air. (JNK)

Birmingham, Alabama, used to have a nickname called “Smoke City”. The air quality used to be so bad in the late 1960s that if you lived in the city. You wouldn’t be able to see 20 feet in front of you because the smog within the city was so thick and low to the ground. When the Clean Air Act was introduced in 1970, Birmingham was ground zero, meaning that depending on if the bill could be successful in reducing their smog would depend on whether the bill was implemented across the rest of the US. It was a huge success. After the bill was passed, around 23 industries in Birmingham were shut down to it would reduce the horrible air pollution that was causing major health problems for people living there. Some of the horror stories from the 50s and 60s of residents living in this dirty air city may seem unfathomable to the modern man. One of these stories is that lawyers and other businessmen would have to pack extra white shirts in their suitcases. Because if they crossed the street to access a different building during the day. The soot from the city’s many steel mills would starch and stain their white undershirts, making them appear dirty and much older than they were. The combination of steel mills dumping soot into the surrounding atmosphere and the geography of the surrounding area added to this poor air quality. Birmingham, much like Los Angeles, sits in a valley that is surrounded by mountains on either side. Creating a temperature inversion above the city, trapping the pollution and smog from escaping. The health effects of those living in the city were unprecedented. Around April of 1970, a local hospital reported that 27% of all the patients that they were treating were sick with Emphysema, which is a chronic lung disease that is a type of COPD. This disease causes damage to the air sacs in the lungs, making it very hard to breathe for those affected. However, Birmingham’s fate turned its head after what is referred to as the “Great Awakening” occurred on Earth Day in 1970. This day marked the day that GASP was formed. GASP stands for the Greater Alliance to Stop Pollution and was a student-formed group that raised awareness of the huge problem that was being ignored by lawmakers in the city of Birmingham and even the state of Alabama. The state governor at the time, George Wallace, was refusing to appoint members to the state’s Air Pollution Control Commission team. Which would work directly with the Clean Air Act and enforce laws and policies to force industry owners to reduce their emissions dramatically. GASP was not happy about this and started a kind of “revolution” that involved sit-ins, walk-outs, and informational seminars and meetings to create enough momentum from the general public that the governor could no longer wait to implement the new CAA policies and appoint members to the board that oversees that these policies are enforced. (JNK)

Air Pollution in the US: By Joseph Kauffman

Air Pollution in the US has a vast array of point and non-point sources. Some of these point sources include power plants, waste incinerators, industrial facilities, and oil/gas drilling sites. According to the U.S. Energy Information Administration, there are around 12,500 active power plants in the U.S. These 12,500 active power plants mainly include utility-scale electric power plants. Utility-scale electric power plants are classified as power plants with a total nameplate electricity generation capacity of at least 1 megawatt. Historically, these power plants are the biggest polluters of our air quality. These coal-fired power plants emit massive amounts of Sulfur dioxide, Nitrogen oxides, Particulate matter, and Carbon dioxide. These are all listed within the EPA’s criteria pollutants. These power plants are also constantly functioning, which results in a constant 24/7 emission rate. Most of these power plants mainly contribute to local degradation of air quality. The accumulation of many power plants constantly emits these air pollutants, which are a major contributor to global warming and can be highlighted as a cause of climate change on a global scale. Although new policies and requirements have been put in place to reduce the emissions of these power plants, the total emissions are significantly lower in the modern era than they were 10 or 15 years ago. Waste incinerators are a major emitter of dioxins and heavy metals, which can be a major health concern for children and those whose minds are still developing. Heavy metals like lead, copper, and silver that are emitted can leach into almost anything, and if ingested by developing children, can lead to major neurocognitive degeneration. This can have a direct impact on IQ and brain development. Industrial facilities have been known to emit toxic gases like VOCs, NOx, and Carbon monoxide. VOCs are a respiratory irritant when introduced to the human body, and when mixed with NOxs in the atmosphere, can produce ground-level smog, which is a major contributor to city-based pollution and can increase ground temperatures, reduce visibility, and irritate eyes and lungs. Lastly, oil and gas drilling sites can result in a release of methane and VOCs. Methane is a potent greenhouse gas that has directly contributed to global warming and the increase in surface temperatures as well. Most of these point sources are regulated by the EPA, and as more policies are put in place to move toward more renewable energy, they will become obsolete. (JNK)

Non-point sources, however, are largely harder to control using government policies. Some examples of major non-point sources of air pollution in the US are vehicle emissions, residential wood burning, agricultural activities, and wildfires. Vehicle emissions are a major contributor to air pollution in densely populated cities like Los Angeles, New York City, and Chicago. Vehicle emissions are a result of incomplete combustion reactions that release COx, NOx, Particulate Matter, and VOCs into the atmosphere. As car engines become more efficient, the amount of incomplete reactions reduces. But due to the sheer number of cars on the road, these small amounts of emissions add up to cause major problems. Although many modern homes in the US have moved on to automatic heating and cooling systems to regulate the temperatures in their homes, some houses look to save money and burn wood instead. This includes burning wood in fireplaces indoors, bonfires/campfires outside, and using wood stoves. The burning of this wood results in a release of Particulate Matter, Carbon Monoxide, methane, and even Nitrogen Oxides. Residential burning of wood is at its highest in the winter, and in some instances, can be even more harmful to the air than car exhaust. Agricultural activities such as using fertilizer, tilling, and livestock release gases such as methane, ammonia, and particulate matter into the air. These releases are especially concentrated in the Midwest and parts of the US, which rely heavily on farmland and animals to produce income. However, these practices are often overlooked as much of the country relies on them to supply food, making it a low-priority non-point source of air pollution. Lastly, wildfires are an increasingly frequent natural and human-made source of air pollution. Historically, wildfires that are caused by natural sources are an important part of the ecological processes that burn old dead vegetation and replace it with new growth. But more recently, they are becoming more and more frequent as a result of human error. These wildfires can release huge amounts of particulate matter, carbon monoxide, and other volatile gases into the air. These pollutants can travel hundreds of miles across the country. This means a wildfire in California can burn for days and have its smoke reach the midwestern/eastern US states and hurt their air quality. (JNK)

Although many of these point and non-point sources appear to be a large part of our society and daily lives. Some solutions can be used to reduce the amount of pollution that they release into the environment. For transportation and car exhaust pollution, the US could promote the use of electric and e-vehicles. Although it would be difficult to implement in rural areas, as another solution option, the people who are driving in rural areas could switch to a corn-based fuel, also known as ethanol, to reduce the amount of bad exhaust that they are putting into the environment. (JNK)

References:

U.S. Energy Information Administration. (2023, July 14). How much carbon dioxide is produced when different fuels are burned? https://www.eia.gov/tools/faqs/faq.php?id=65&t=2

World Health Organization. (n.d.). Wildfires. https://www.who.int/health-topics/wildfires

U.S. Environmental Protection Agency. (2023, June 14). Basic information about nonpoint source (NPS) pollution. https://www.epa.gov/nps/basic-information-about-nonpoint-source-nps-pollution

United Nations Office for Disaster Risk Reduction. (n.d.). Hazardous event. https://www.undrr.org/understanding-disaster-risk/terminology/hips/en0002

“Aqi Basics.” AQI Basics | AirNow.Gov, AirNow.gov, U.S. EPA, www.airnow.gov/aqi/aqi-basics/. Accessed 4 Mar. 2025.

“Above-Average Winds and Long-Term Drought Affect El Paso’s Air Quality.” Texas Standard, www.texasstandard.org/stories/el-paso-air-quality-winds-drought-dust/#:~:text=quality%20%7C%20Texas%20Standard-,Above%2Daverage%20winds%20and%20long%2Dterm%20drought%20affect%20El%20Paso’s,year%20since%20at%20least%202000. Accessed 4 Mar. 2025.

EPA, Environmental Protection Agency, gispub.epa.gov/airnow/?tab=0&contours=ozonepm&monitors=none&xmin=-18127147.603810497&xmax=-5173211.546268552&ymin=1741482.3877635554&ymax=7562926.461961032. Accessed 4 Mar. 2025.

U.S. Department of the Interior. (n.d.). Air Quality. National Parks Service. https://www.nps.gov/samo/learn/nature/airquality.htm#:~:text=The%20development%20of%20especially%20strong,the%20Los%20Angeles%20metropolitan%20area.

Year-round particle pollution: State of the Air. Year-Round Particle Pollution | State of the Air | American Lung Association. (n.d.). https://www.lung.org/research/sota/key-findings/year-round-particle-pollution

Byington, B., Byington, P., Pat Byington Longtime conservationist.  Former Executive Director at the Alabama Environmental Council and Wild South.  Publisher of the Bama Environmental News for more than 18 years.  Career highlights include playing an active role in , Longtime conservationist.  Former Executive Director at the Alabama Environmental Council and Wild South.  Publisher of the Bama Environmental News for more than 18 years.  Career highlights include playing an active role in the creation of Alabama’s Fore, & Articles: 2731. (2018, September 6). “smoke city” – birmingham air pollution our past and future. Bham Now. https://bhamnow.com/2017/08/17/smoke-city-birmingham/