UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

The Honorable Alejandro Javier Garcia Padilla 

Governor of Puerto Rico 

La Fortaleza 

P.O. Box 9020082 

San Juan, Puerto Rico 00902-0082 

Dear Governor Garda Padilla: 

THE ADMINISTRATOR 

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 of the standard. 

On December 14, 2012, the EPA strengthened the annual, health-based fine particle standard from 15.0 

micrograms per cubic meter (f..lg/m3) to 12.0 J.tg/m3. Thousands of scientific studies have linked exposure 

to these tiny particles- approximately 1/30th 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 staff have shared with the EPA throughout this process to 

assess fine particle pollution levels in communities across your state and the impact of emission sources 

that could be contributing to unhealthy air. Because Puerto Rico does not have sufficient air quality 

monitoring data to determine whether your territory meets the 2012 annual fine particle standard, !he 

EPA is designating Puerto Rico "unclassifiable." The EPA will work closely with Puerto Rico to ensure 

that identified problems with air quality monitoring data are corrected. The agency intends to reassess 

levels of fine particle pollution throughout Puerto Rico once sufficient complete air monitoring data are 

available. 

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 pruticle pollution standards are already working to 

reduce unhealthy levels of fine pru·ticle pollution. In addition, current ru1d upcoming federal standards 

and safeguards, including pollution reduction rules for power plants, vehicles and fuels will assure 

steady reductions of fine particle pollution and will protect public health in communities across the 

country. 

Internet Address (URL) • hllp:l/www.epa.gov 

Recycled/Recyclable • Printed with Vegetable Oil Based Inks on 100% Postconsumer, Process Chlorine Free Recycled Paper 
Together, we have made considerable progress to reduce fine particle pollution. Nationwide, monitored 

levels of fine particle pollution have fallen 34 percent since 2000 when we first began nationwide 

monitoring for particles of this size. I am confident this progress will continue as we work together 

towards our shared goal of clean air. For additional information about these designations, please visit 

our website at: w·ww.epa.gov/pmdesignations. 

If you have questions or concerns, please contact me or your staff may contact Mark Rupp, Deputy 

Associate Administrator for Intergovernmental Relations, at n.tpp.markr~? epa.gov or at (202) 564-7178.