U.S. EPA has proposed designating 14 areas in six states as out of compliance with the 2012 pollution standard for airborne fine particulates (PM2.5).  In 2012, EPA tightened the particulate limit from 15 micrograms per cubic meter to 12 micrograms per cubic meter, based on information about health effects.  The list of 14 areas out of compliance with the standard is based on monitoring data from 2011 to 2013.  The nonattainment areas are in Pennsylvania, Kentucky, Indiana, Ohio, California and Idaho. For California, the following counties are listed as not meeting the standard: Plumas, San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare, Kern, San Bernardino, Riverside, Los Angeles, Orange and Imperial Counties.  EPA is accepting public comment on the list until the end of the month. States with nonattainment areas have 120 days to work with the agency and provide more information before EPA makes a final decision.  Under the Clean Air Act, states with areas not meeting the federal standard must come up with plans to reduce pollution from sources of fine particulate matter, primarily combustions sources including trucks and tractors.