UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D .C. 20460

The Honorable Deval Patrick Governor ofMassachusetts Office ofthe Governor, Room 105 Boston, Massachusetts 02133 Dear Governor Patrick: THE ADMIN I STRATOR

I am writing to summarize the U.S. Environmental Protection Agency's recent action to address fine particle pollution in your state. As required by the Clean Air Act, the EPA has determined which areas are meeting the national ambient air quality standards for fine particle pollution and which areas must take steps to reduce emissions that contribute to violations ofthe standard. On December 14, 2012 , the EPA strengthened the annual, health-based fine particle standard from 15 .0 micrograms per cubic meter (flg/m3 ) to 12.0 flgfm 3

. Thousands of scientific studies have linked exposure to these tiny particles - approximately 1130th the size of a human hair-with serious human health problems including premature death in people with heart and lung disease, nonfatal heart attacks, and increased hospital admissions and doctor and emergency room visits for respiratory and cardiovascular disease. I appreciate the information you and your staffhave shared with the EPA throughout this process to assess fine particle pollution levels in communities across your state and the impact ofemission sources that could be contributing to unhealthy air. After considering your recommendations, reviewing the most recent certified fine particle air quality data for your state and evaluating factors to assess contribution to nearby levels offine particle pollution, I have determined that no area within Massachusetts violates the 2012 standard or contributes to a nearby violation ofthe standard. As a result, the EPA is designating all ofMassachusetts "unclassifi able/attainment. " Because air quality monitoring for 2014 is nearly complete, if a state or tribe requests it, the EPA will evaluate the status of an area based on its annual fine particle monitoring data for 2012-2014. If you would like the EPA to re-evaluate any areas within your state, please submit to the EPA, complete, quality-assured and certified air quality data for 2014 by February 27 , 2015. The EPA shares responsibility with the states and tribes for managing particle pollution levels
. Efforts by states and tribes to attain the 1997 and 2006 fine particle pollution standards are already working to reduce unhealthy levels offine particle pollution. In addition, current and upcoming federal standards and safeguards, including pollution reduction rules for power plants, vehicles and fuels will assure steady reductions offine particle pollution and will protect public health in communities across the country.

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. epa .gov Recycled/Recyclable • Pri nted w i th Vegetabl e Oil Based Inks on 1 00% Postconsumer, Process Chlori ne Free Recyc led Pap e rTogether, we have made considerab l e progress to reduce fine particle po ll u t ion. Nationwide, monitored levels of fi n e particle pollut i o n fell 34 percen t s in ce 2000 when we first began nationwide monitoring for particles of t his size. I am confident this progres s wi ll accelerate as toget h er we cont i nue to work towards our shared goal of clean air. For additional i nfo rm ation about these designations, please visi t our websi t e at: www.epa.gov / pmdesignations .

If you have questions or concerns, please contact me or your staff may contact Mark Rupp , Deputy Associate Adm ini strato r for Intergovernmenta l Relations, at rupp . mark @ epa . gov or at (202) 564 -71 78.