It nas been contended that assumlng present day money saving advantage examlnatlons had been applied to choices, for example, whether to order the expulsion of lead from fuel, block the development of two proposed dams simply above and underneath the Grand Canyon on the Colorado River, and manage laborers' openness to vinyl chloride, the actions could not have possibly been executed [albeit all are considered exceptionally successful},[39] The US Clean Air Act has been refered to in review concentrates as a case in which advantages surpassed costs, yet information on the advantages [inferable generally to the advantages of lessening particulate contamination) was not accessible until numerous years later.[39]