The efficient regulation of hazardous pollutants should take exposure into account—the more persons exposed to a given pollutant concentration, the larger is the damage caused by it and therefore the smaller is the efficient concentration level, all other things being equal. An alternative point of view would simply ensure that concentrations would be held below a uniform threshold regardless of the number of people exposed. For this point of view, the public policy goal is to expose any and all people to the same concentration level—exposure is not used to establish different concentrations for different settings. What are the advantages and disadvantages of each approach? Which do you think represents the best approach? Why?