Next Up: Nitrogen Dioxide Standard
In what could be the last major clean air policy decision of the Bush Administration, EPA is scheduled to publish its Advanced Notice of Proposed Rulemaking (ANPR) on the primary nitrogen dioxide (NO2) NAAQS in the Federal Register on January 16, 2009. The ANPR could be signed as early as January 9, 2009.
The notice will solicit public comments on a range of policy options for revising the standard. What’s at stake? The current annual average standard was set in 1971 and has not been updated since then. New clinical and epidemiology studies show respiratory problems with short term exposures. A stringent new short-term standard is needed to protect the health of people with asthma. At the same time, EPA should not abandon the annual average standard.
In a final Risk and Exposure Assessment (REA) released last month, EPA staff recommended a range of maximum hourly concentrations of 50-100 ppb, or possibly 50-200 ppb. The REA also suggested dropping the annual average standard. The Clean Air Scientific Advisory Committee (CASAC) supported a range of 50-100 ppb; firmly recommended that the upper end or range not exceed 100 ppb; and supported retention of the current annual average standard. See CASAC letter online.
Comments of the American Lung Association are attached. ALA comments on Nitrogen Dioxide REA
EPA’s analysis of air quality monitoring data indicated that of the options analyzed, only a 1-hour standard of 50 ppb would result in additional public health protection. Also, a quantitative risk assessment for Atlanta showed that 50 ppb was the only level that reduced emergency room visits in that city.
The current annual standard for NO2 is not violated anywhere. The highest concentrations of NO2 are found on roadways and near roadways. The current monitoring network does not measure these roadway and near roadway concentrations. A new standard would have to be coupled with a change in monitor siting to have any effect.
