text: The Administrator , in consultation with the Secretary of Energy , must conduct a study that addresses a number of specific factors regarding , among other the need for further reductions of these pollutants from affected EGUs and other sources to attain or maintain the national ambient air quality standards ; whether adjusting any of the limitations would have benefits that would justify the costs of such adjustment ; the relative marginal cost effectiveness of the reductions from affected EGUs ; and the feasibility of attaining the limitations and any alternative limitations .
  
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  There are numerous factors that affect the air quality .