The National Mining Association (NMA) and the National Cattlemen’s Beef Association (NCBA), two bodies that provide significant business and job activity in the western United States, have joined forces to both oppose and support different elements of EPA’s proposal to revise the national ambient air quality standards (NAAQS) for both coarse and fine particulate matter (PM). 
EPA and CASAC
Primarily, the NMA/NCBA are concerned about any EPA attempt to modify the existing PM-10 or coarse PM NAAQS.  In fact, in its June 2012 action, the EPA proposed to retain the current PM-10 24-hour standard.  But this action was taken against the recommendation of EPA’s Clean Air Scientific Advisory Committee (CASAC), which believes the Agency should lower the current annual PM-10 NAAQS of 150 µg/m3 to a range between 75 µg/m3 and 85 µg/m3 with a 98th percentile form.  A change in the percentile form would effectively throw more counties in the western U.S. into nonattainment.  While the EPA did not accept CASAC’s recommendation, the Agency did invite public comments on the benefits and drawbacks of doing so.  The invitation and the possibility that the EPA may change its mind compelled the NMA/NCBA to go to great lengths in its comments on the proposal to argue against the potential for a more stringent PM-10 standard. 
According to the NMA/NCBA, changing the PM-10 standard as the CASAC recommends may force the shutdown or curtailment of operations that are now having difficulty meeting the current limits.  They state that drops in employment have been linked to increased declines in health.   The groups cite one study that found that near-term mortality rates increased by as much as 100 percent following job loss and remained significantly elevated throughout the 20-year postperiod covered by the study.
Rural and urban PM-10
The NMA/NCBA also point to considerable uncertainty about the health risks posed by coarse PM.  The groups note that PM-10 levels in rural areas of the West consist primarily of crustal materials that originate on the ground.  On the other hand, urban coarse PM contains by-products of incomplete combustion and metals and other contaminants from anthropogenic sources, which, they state, may pose a much higher health risk.  The NMA/NCBA are concerned that most PM-10 health assessments relied on by the EPA and the CASAC are based on urban PM-10.  In any event, the high degree of uncertainty about the health effects of PM-10 should dissuade the EPA from accommodating CASAC’s recommendation and revising the PM-10 NAAQS, say the groups.
PM-2.5 visibility standard
Regarding fine PM or PM-2.5, the NMA/NCBA mainly oppose EPA’s addition of a secondary visibility standard.  The argument here is mostly legal.  The groups state that the EPA may not use the NAAQS to regulate visibility because it is not an air pollutant.  Furthermore, they argue, that even if the Clean Air Act (CAA) allowed a NAAQS for visibility, the Agency would need to differentiate between PM-2.5 in the atmosphere and other substances, some that occur naturally and some that are anthropogenic.  “These substances are not, either singly or in combination, criteria pollutants for which NAAQS may be adopted pursuant to the CAA,” state the groups.  “Put another way, EPA cannot use NAAQS to indirectly regulate multiple substances which are not criteria pollutants under the guise of setting a visibility standard for purposes of a secondary NAAQS for PM-2.5,” the groups say.
               According to the NMA/NCBA, EPA’s proposal also fails to address the inadequacy of the exceptional events regulations when high winds occur in the West and problems with air quality modeling that overpredicts exceedances.  The Agency also did not comprehensively analyze the costs the proposed revisions would have on the nation, they argue.
               Comments by the NMA/NCBA are at http://www.beefusa.org/CMDocs/BeefUSA/NCBAPMComments.pdf.  EPA’s proposed revisions to the PM NAAQS were published in the June 29, 2012, FR.