Massachusetts and a new EPA standard
posted at 7/18/2012 8:42 AM EDT
How much will Massachusetts have to do because of the EPA 1-hour rule on nitrogen dioxide in the air? A new rule adopted in 2010, after four years of review, supplements a standard adopted in 1971, limiting nitrogen dioxide to an annually averaged maximum concentration of 53 parts per billion (ppb). The new rule will also limit nitrogen dioxide to a maximum concentration of 100 ppb, averaged hour-by-hour. [ Primary national ambient air quality standards for nitrogen dioxide, U.S. EPA (75 FR 6473), February 9, 2010, at https://www.federalregister.gov/articles/2010/02/09/2010-1990/primary-national-ambient-air-quality-standards-for-nitrogen-dioxide ]
During the Walker Bush administration, EPA was required to review its nitrogen dioxide and sulfur dioxide air quality standards as the outcome of a lawsuit. In violation of the Clean Air Act, EPA had failed to conduct periodic reviews of standards. [ Consent Decree, Center for Biological Diversity et al. v. Stephen L. Johnson, Administrator, U.S. EPA, U.S. District Court for the District of Columbia, Civ. No. 05-1814, November 19, 2007, at http://www.epa.gov/ttn/naaqs/standards/no2so2sec/data/20071119_consent_decree.pdf ]
Settlement of the lawsuit did not commit EPA to any particular approach to air quality reviews or guarantee that it would change any prevailing standard. Both a scientific review and a policy review of standards were completed by November, 2008. [ Integrated science assessment for nitrogen dioxide, at http://www.epa.gov/ttn/naaqs/standards/nox/s_nox_cr_isi.html ] [ Risk and exposure assessments for nitrogen dioxide, at http://www.epa.gov/ttn/naaqs/standards/nox/s_nox_cr_rea.html ]
Following the agreed timetable, during the Obama administration EPA proposed to change the primary air quality standard for nitrogen dioxide by adding a 1-hour limit, using a complex scheme in which three years of hour-by-hour measurements will be considered (similar to a scheme used for ground-level ozone). The American Petroleum Institute challenged the new rule in the U.S. Court of Appeals for the DC Circuit, which has national jurisdiction in such cases, claiming that EPA lacked adequate justification and that its actions were arbitrary and capricious. [API et al. v. U.S. EPA, Nos. 10–1079 and 10–1080]
EPA was upheld in a unanimous Circuit Court decision, against which a Supreme Court appeal would appear to have poor chances, given the Supreme Court's recent record of support for EPA rules. [ Jonathan Stempel, Reuters, Federal appeals court upholds EPA air-quality rule, Scientific American, July 18, 2012, at http://www.scientificamerican.com/article.cfm?id=appeals-court-upholds-epa-air-quali ]
Unlike other recent air quality controversies, the one over nitrogen dioxide was scientifically murky. The original interest in pollution from nitrogen oxides was because of the potential to produce ground-level ozone, by reacting with organic vapors in sunlight. Nitrogen oxides by themselves have usually been seen as a less significant health risk. The reviews finished in 2008 turned up a new but problematic observation: for some but not all asthma sufferers, short-term exposures above the current 53 ppb limit appear more hazardous than long-term exposures at or under that limit.
So far, Massachusetts appears to have done little about the new EPA rule. Its standard for nitrogen dioxide has not changed, and it may lack short-term monitoring that complies with the new rule. Lack of knowledge about most short-term air-pollution trends is a key problem for EPA in trying to regulate effectively. Under the new rule, Massachusetts probably has to install up to three new monitoring sites near highways. For 2010, it reported having only one "continuous monitor" for nitrogen oxides. Whether or not Massachusetts achieves air quality standards under the new rule will not be known before 2016.
[ Massachusetts air quality standards, Department of Environmental Protection, 2012, at http://www.mass.gov/dep/service/regulations/310cmr06.pdf ]
[ Massachusetts 2010 air quality report, Department of Environmental Protection, 2011, at http://www.mass.gov/dep/air/priorities/10aqrpt.pdf ]
[ Massachusetts air quality monitoring sites, Department of Environmental Protection, 2010, at http://www.mass.gov/dep/air/aq/aq_measure.htm ]