Air quality refers to the condition or cleanliness of the air in a specific environment, typically measured by the concentration of pollutants and harmful substances present. Key indicators of air quality include levels of particulate matter (PM), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), and volatile organic compounds (VOCs). Good air quality is essential for human health, environmental protection, and overall well-being, while poor air quality can lead to respiratory problems, cardiovascular diseases, and negative impacts on ecosystems. Monitoring air quality is crucial for public health and regulatory efforts.