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

The Honorable Alejandro Jav i er Garcia Padilla Governor of Puerto Rico La Fo rtaleza P
. O. Box 9020082 San Juan, Puerto Rico 00902-0082 Dear Governor Garda Padilla: THE ADMINISTRATOR

I am writing to summar i ze the U.S
. Env ironmental Protection Agency ' s recent action to address fine particle pollut ion in your state. As required by the Clean Air Act , the EPA has de termined which areas are mee ti ng the nati onal ambien t air quali ty standards for fine particl e po llution and which areas must take steps to reduce emissions that cont ribute to vio l ations of the standard. On December 14, 20 12, the EPA stre ngthe n ed the annual, h ealth-based fine particle standard f rom 15.0 m icrograms per cubic meter (f..lg/ m 3 ) to 12.0 J.tg/m3

. Thousands of scientific studies have linked exposure to these tiny particle s - approximately 1/ 30th the s i ze of a human hair

- w ith 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 app reciate th e informat ion you and yo ur staff have shared with the EPA throughout this process to assess fine particle pollution leve l s i n communities across your state and the impact of emission sour ces that cou ld be contributing to unheal thy air. Because Puerto Rico does n ot have suffic i ent air quality monito rin g data to dete rm i ne w hether your territory meets the 2012 annual fine particle s t andard, ! h e EPA is designating Puerto Rico "unclassifia bl e. " The E PA will work closely w i th 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 sha res responsibility w ith the states and tribes for managing particle poll u tion levels. Effort s by states and tribes to attain the 1997 and 2006 fine pruticle polluti on standards are already working to reduce unhea lthy leve ls of fine pru·ticle pollutio n. In addi ti on , current ru1d up coming federal standards and safeguards, includi ng pollution reducti on rules for power plants, ve h icles and fuels will assure steady reductions of fine particle pollution and will protect pub lic health i n communi ties across the country.

Internet Add ress (URL) • hllp : l/www
. epa . gov Recycled/Recyclable • P r i nted with Vegetable Oil Based Inks on 100% Postconsume r, P roce ss Chlorine Free Recyc l ed PaperTogethe r , we have made conside r able progress to reduce fine particle poll u t i on . Nationw id e, monitored l evels of fine part i c l e pollution have fallen 3 4 pe rcent since 2000 when we fi r st began nationwide monitoring for particle s of this size . I am confident this progress will continue as we work together towa r ds our sha red goal of clean a i r. For add itional information about these desi g nations , please visit ou r website at: w · ww.epa.g ov/pm de sig n atio ns . If you have questions or concerns, please contact me or your staff may contact Mark Rupp , Dep uty Associate Administra t or for Intergovernmental Rel at i ons, at**n.tpp.markr~? epa.gov**  or at (202) 564-7178 .