Legal Regulations
In general, there are two types of air quality standards. The first class of standards (such as the U.S. National Ambient Air Quality Standards and E.U. Air Quality Directive) set maximum atmospheric concentrations for specific pollutants. Environmental agencies enact regulations which are intended to result in attainment of these target levels. The second class (such as the North American Air Quality Index) take the form of a scale with various thresholds, which is used to communicate to the public the relative risk of outdoor activity. The scale may or may not distinguish between different pollutants.
Read more about this topic: Air Quality
Famous quotes containing the words legal and/or regulations:
“I am opposed to writing about the private lives of living authors and psychoanalyzing them while they are alive. Criticism is getting all mixed up with a combination of the Junior F.B.I.- men, discards from Freud and Jung and a sort of Columnist peep- hole and missing laundry list school.... Every young English professor sees gold in them dirty sheets now. Imagine what they can do with the soiled sheets of four legal beds by the same writer and you can see why their tongues are slavering.”
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“If it were possible to make an accurate calculation of the evils which police regulations occasion, and of those which they prevent, the number of the former would, in all cases, exceed that of the latter.”
—Karl Wilhelm Von Humboldt (1767–1835)