Way back when I took environmental engineering 101, the first day the prof told us that "a pollutant is a resource that has been misplaced". Since that time environmental engineers have worked diligently to clean up the environment and have, for the most part, done an admirable job. Environmental activists have never been satisfied, constantly pushing for stricter limits on emissions, and we in turn have responded. As the devices to measure pollutant concentrations has become more accurate, activists have insisted on more zeros up to the no detection limit, and engineers have responded and many times met those goals. Designers of combustion machines have long sought perfection in their chemical equation of hydrocarbon + spark = CO2 + water + heat and have for practical purposes done so. Discovering that they are losing the game of "betcha can't", activists have simply redefined "pollutant" to be anything emitted by man's activities.
