What is a Metropolitan Statistical Area (MSA)?
An MSA is: 1) a county or group of contiguous counties that contains at least one city of 50,000 inhabitants or more, or 2) an urbanized area of at least 50,000 inhabitants and a total MSA population of at least 100,000 inhabitants. The contiguous counties are included in an MSA if, according to certain criteria, they are essentially metropolitan in character and are socially and economically integrated with the central city or cities.
DAQ is obligated to report the AQI for all ambient air pollutant data monitored under the requirements of the Clean Air Act Amendment of 1990. The MSA is defined by the US Department of Commerce, Bureau of The Census. MSA is a geographic entity designated as one or more counties in a metropolitan area, except in New England, where MSA is defined in terms of county subdivisions.
An MSA is a geographic area comprised of a parish (or county) with a central city (or twin cities) of 50,000 inhabitants or more, plus contiguous parishes that have close economic and social relationships with the central parish. Louisiana has eight multi-parish MSAs. Whether or not a parish is included in an MSA is determined by commuting patterns derived from the latest census reports.
