the united states has been restricting soot emissions  in draconian fashion since the clean air act of 1963.
the united states has been restricting soot emissions  in draconian fashion since the clean air act of 1963.
clean air act (united states):152
the clean air act of 1970 (1970 caa) authorized the development of comprehensive federal and state regulations to limit emissions from both stationary (industrial) sources and mobile sources.