Examining the Air We Breathe : EPA Should Evaluate Cumulative Impacts When it Promulgates National Ambient Air Quality Standards

Inhaling air pollutants can lead to a variety of adverse respiratory and cardiovascular health effects. This potential risk for health impacts is likely greater when the mixture of pollutants that exists in ambient air, rather than isolated pollutants, are inhaled. Despite the evidence of potential cumulative impacts, EPA has continued to focus its analysis of health impacts on isolated pollutants instead of the actual mixture we breathe. This article proposes that EPA should evaluate and consider cumulative health impacts when it sets national ambient air quality standards under the Clean Air Act. EPA is considering two pollutants together to determine their impact on the environment; it should do the same type of evaluation for human health impacts. Consideration of cumulative health impacts is consistent with the Act’s requirement to set standards at a level requisite to protect public health, could translate into a more accurate way to estimate risks, and could provide a tool for prioritization of emission reductions in the most heavily impacted communities