Hazardous air pollutants are released by sources such as chemical plants, and motor vehicles (cars, trucks, buses, etc.) Inspection and Maintenance Program (I/M Program): Auto inspection programs are required for some polluted areas.
(Hazardous air pollutants; are released; by sources such as chemical plants) (Auto inspection programs; are required; for some polluted areas)
Hazardous air pollutants Auto inspection programs
are released are required
by sources such as chemical plants
for some polluted areas