The level of pollutants in Wiesbaden's air is measured continuously. Current figures are provided by the Hessian State Institute for Nature Conservation, Environment and Geology in its daily and monthly air hygiene reports as well as in hourly measurements.

Since 1988, the city's environmental department has been using a measuring van to record air quality and noise pollution at selected locations in the city and its outlying districts.

The following substances are analyzed:

• Nitrogen dioxide (NO2)
• Nitrogen monoxide (NO)
• Particulate matter (PM 2.5 / PM 10)
• Ozone (O3)
• Carbon monoxide (CO)

The measurement method for determining air quality is based on the principles of the 39th Federal Immission Control Ordinance (39th BImSchV). Since 1994, the focus has been on direct traffic-related measurements in the street area. Laws continue to prompt the city of Wiesbaden to measure pollutant levels on busy roads.

The data collected also forms the basis for the planning of commercial settlements as well as urban traffic development, landscape and urban land-use planning.