Clean air comprises several gasses, though Earth’s atmosphere is primarily nitrogen and oxygen. Various human activities and natural processes can alter the atmospheric composition in a region, making the air harmful to local inhabitants. Air quality worldwide is closely tied to climate change, with many air pollutants also functioning as greenhouse gas emissions.
Air quality in the United States is a problem, as it is for many nations. A 2021 IQAir report found New Caledonia to have the cleanest air on the planet, with an annual particulate matter (PM) concentration of just 3.8. Unfortunately, New Caledonia was one of just four nations with a score aligned with World Health Organization (WHO) standards. In fact, roughly 99 percent of the global population breathes air not within WHO standards, with low and middle-income countries suffering from harmful pollution levels. The United States ranked 28th with a PM concentration of 10.3, which exceeds WHO guidelines by approximately 200 percent.
A few of the most common sources of air pollutants include automobiles, industrial operations, wildfires, and various household devices. There are a few differences between household or indoor air pollution and ambient or outdoor air pollution. Household air pollution is a widespread issue, impacting approximately 2.4 billion individuals. Open fires and stoves that use fossil fuels or biomass are common sources of household air pollution, responsible for more than three million deaths annually. Diseases and health conditions associated with indoor air pollution range from ischaemic heart disease to stroke.
On the other hand, outdoor air pollution is viewed by scientists as one of the most significant threats to human health. Together, indoor and outdoor air pollutants account for nearly seven million premature deaths annually.
There is no shortage of side effects with prolonged exposure to unclean air. Symptoms include eye irritation, breathing problems, coughing, and shortness of breath. People with respiratory conditions such as asthma have difficulty with polluted air. Long-term effects can be even more severe. For example, regularly breathing second-hand cigarette smoke can increase the risk of heart disease, lung cancer, and stroke by up to 30 percent.
Some air pollutants have a dark color and strong, distinct odor. Others have no warning signs. For example, carbon monoxide is an invisible, odorless gas that quickly has fatal consequences. All homeowners are strongly encouraged to install carbon monoxide detectors.
The Environmental Protection Agency (EPA) air quality index (AQI) is a reference point for clean air. Air quality is scored from zero to 500, with an ideal score of 50 or lower. Any number over 300 indicates hazardous air. An AQI of over 100 is comparable to breathing exhaust fumes. The cleanest air in the US is in Hawaii, with an average AQI of 21.2. The most polluted air in America is in Los Angeles, followed by the nearby cities of Bakersfield and Visalia.
The EPA also oversees and manages clean air, land, and water throughout the United States. The agency is a critical point of contact for those looking for clean air solutions.