Air Quality Standard Improvement Act of 2000

Air Quality Standard Improvement Act of 2000 - Amends the Clean Air Act to require the Administrator of the Environmental Protection Agency, in carrying out such Act (including establishing a new or revised air quality standard), to base any scientific or technical conclusions on: (1) the best available, peer-reviewed science and supporting studies conducted in accordance with sound and objective scientific practices; (2) data collected by accepted methods or the best available methods; and (3) data that have been made publicly available.Requires the Administrator to ensure that the presentation of information on public health effects concerning any new or revised air quality standard is comprehensive, informative, understandable, and available for public comment prior to the promulgation of any regulation under the Act.Directs the Administrator, in a document made available to the public in support of a regulation proposed or promulgated under the Act concerning an air quality standard to specify: (1) each population addressed by any estimate of public health effects; (2) the expected risk or central estimate of risk for the specific populations or resources and each upper-bound or lower- bound of risk; (3) each significant uncertainty identified in the process of the assessment of public health effects and studies that would assist in resolving such uncertainties; and (4) peer-reviewed studies that support, are relevant to, or fail to support any estimate of public health effects and the methodologies used to reconcile inconsistencies in the scientific data.Requires the Administrator, as part of the process of proposing a new or revised air quality standard, to publish in the Federal Register and seek public comment on an analysis of specified factors, including: (1) quantifiable and nonquantifiable benefits that are likely to occur as the result of actions taken to comply with the standard; (2) quantifiable and nonquantifiable health benefits that are likely to occur from reductions in related pollutants that may be attributed to compliance with the standard; (3) quantifiable and nonquantifiable costs that are likely to occur as the result of actions taken to comply with or attain the standard; (4) incremental costs and benefits associated with each alternative standard considered; (5) effects of the affected air pollutant on the general population; and (6) risks that may occur as the result of compliance with or attainment of the standard.Authorizes appropriations.Directs the Administrator, for each new or revised air quality standard proposed, to conduct and publish for public comment a cost-benefit analysis to determine whether the benefits of the standard justify or do not justify the costs. Authorizes the Administrator to analyze the potential distributional effects of each such standard. Permits the Administrator, upon determining based on such analysis that the benefits do not justify the costs, to promulgate an alternative standard at a cost that is justified by the benefits.Authorizes appropriations.