Environmental resource guide :   air quality : a series of classroom activities for GRADES 6-8 /  
produced by Tennessee Valley Authority, Environmental Education Section for Air & Waste Management Association, Education Council in cooperation with Environmental Protection Agency, Office of Air Quality Planning and Standards. 
 - Pittsburgh, PA :   Education Program Manager, Air & Waste Management Association,   c1991. 
 - 127 p. :   il. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ar--Controle de qualidade.<br/>Ar--Poluição.
<br/><br/><label>Dewey Class. No.: </label>363.7392