when is noise pollution added in pollution list
Noise pollution Up until the 1970s governments tended to view noise as a "nuisance" rather than an environmental problem.
Air quality index The United States Environmental Protection Agency (EPA) has developed an Air Quality Index that is used to report air quality. This AQI is divided into six categories indicating increasing levels of health concern. An AQI value over 300 represents hazardous air quality and below 50 the air quality is good.[10]