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U.S. Non-Attainment Areas for ozone pollution in June 2007. In United States environmental law, a non-attainment area is an area that exceeds pollution limits for one or more criteria pollutants: ozone (O 3), atmospheric particulate matter (PM 2.5 /PM 10), lead (Pb), carbon monoxide (CO), sulfur oxides (SO x), and nitrogen oxides (NO x). [1]
Looking down from the Hollywood Hills, with Griffith Observatory on the hill in the foreground, air pollution is visible in downtown Los Angeles on a late afternoon.. Air pollution is the introduction of chemicals, particulate matter, or biological materials into the atmosphere that cause harm or discomfort to humans or other living organisms, or damage ecosystems.
These monitors help ensure air quality standards are met and also provide important data for studying pollution trends. The information shows significant improvements in air quality over recent decades. From 1980 to 2019, levels of carbon monoxide, lead, and sulfur dioxide dropped by over 80%, and particulate matter also decreased substantially.
The AQI measures air quality based on five major pollutants that the Clean Air Act regulates: ozone, particle pollution (AKA particulate matter or PM2.5), carbon monoxide, nitrogen dioxide and ...
The U.S. has a measurement system for air quality called the air quality index (AQI). The AQI has six color-coded categories with a value system that runs from zero to 500.
As a result of EPA's regulatory efforts, levels of lead in the air [in the United States] decreased by 86 percent between 2010 and 2020." [283] The concentration of lead in the air in the United States fell below the national standard of 0.15 μg/m 3 [284] in 2014. [285] Skin exposure may be significant for people working with organic lead ...
The findings highlight the long-term persistence of contaminants introduced by human activities in the environment, research suggests.
Air pollution can cause diseases, allergies, and even death; it can also cause harm to animals and crops and damage the natural environment (for example, climate change, ozone depletion or habitat degradation) or built environment (for example, acid rain). [3] Air pollution can occur naturally or be caused by human activities. [4]