Project Overview

Furtherance of a national goal that calls for “the prevention of any future, and the remedying of any existing, impairment of visibility in mandatory Class I federal areas which impairment results from manmade air pollution.” The Regional Haze Rule (RHR) expanded this mandate by requiring monitoring in locations representative of the 156 visibility-protected federal Class I areas. IMPROVE was designated as the visibility monitoring network to be used to carry out this responsibility.


Determine compliance with (PM-10) National Ambient Air Quality Standards. Determine concentrations and composition of fine particles (PM-2.5) of relevance to light scattering, light absorption, human health and biological effects. Data available for use in conjunction with other biological, physical and chemical variables in trend and relationship assessments.

Dataset Availability

Downloadable: 8 datasets

See the full list of available data


Status - Active

Start date: 1988-09-01

Study Area

Download Shapefiles