38 Air Quality

Introduction of Air Quality:

Air quality refers to the conditions in which the air we breathe and live in is at. According to the Centers for Science Education, Air Quality is, “When air quality is good, the air is clear and contains only small amounts of solid particles and chemical pollutants. Poor air quality, which contains high levels of contaminants, is often hazy and dangerous to health and the environment. Air quality is described according to the Air Quality Index (AQI), which is based on the concentration of pollutants present in the air at a particular location (Center for Science Education, 2025). To understand Air Quality, you need to understand what the Air Quality Index (AQI) is. This is a scale determined by the EPA which is used for reporting daily air quality. This is a scale that indicates how clean or polluted your air is, and what health effects may be a concern based on the AQI. This scale can be determined by color. Green indicates low levels of concern with an index value between 0-50. This ensures that the air quality is satisfactory, and poses little to no risks to human health. Yellow indicates moderate levels of concern, with an index value of 51-100. This explains that the air quality is acceptable, however individuals with health concerns may be sensitive to this AQI. Orange causes levels of concern for unhealthy/sensitive groups with an index value between 101-150. This explains that the general public will feel unaffected, while those with health issues may experience adverse effects. Red indicates an unhealthy level of concern, with an index level of 151-200. This explains that the general public may experience health effects, while those who are unhealthy/sensitive may experience more serious health effects. Purple indicates a very unhealthy level of concern with an index level of 201-300. This triggers a health alert that can affect the health of everyone. Lastly, maroon indicated hazardous levels of concern with an index level of 301 and higher. This triggers a health warning that alerts everyone is likely to be affected.

First in Air Quality. IQAir. (n.d.). https://www.iqair.com/us/newsroom/what-is-aqi

The Clean Air Act (CAA), which regulates air emissions from stationary and mobile sources, aims to protect public health and set air quality standards. This is enforced by the Environmental Protection Agency (EPA). The Clean Air Act (CAA) provides the legal foundations for air quality by regulating standards, while the Air Quality Index(AQI) displays real-time measures of air quality based on these regulations. Further, the EPA (Environmental Protection Agency) has established five major pollutants that are regulated by the Clean Air Act. These pollutants include ground level ozone (O3), known as smog, which is formed when sunlight reacts with nitrogen oxides. Particulate matter (including PM 2.5 and PM10), which is a solid or liquid particle that forms from power plants, vehicle traffic, construction sites, and indoor heaters and stoves. Carbon monoxide (CO), which comes from the incomplete burning of fossil fuels.  Sulfur dioxide (SO2), which is a gas that comes from burning fossil fuels/materials that contain sulfur. Lastly, nitrogen oxides (NOx) are pollutants that come from burning fuel at high temperatures in vehicles, power plants, and industrial processes (Access Environmental Planning, 2025). 

Air Quality on a Global Level:

Air Quality on a Country Level:

Air Quality on a State/Local Level: