[20151223]R43953_2013年细颗粒物（PM2.5）国家环境空气质量标准（NAAQS）：指定非附着区域.pdf

2013 National Ambient Air Quality Standard (NAAQS) for Fine Particulate Matter (PM2.5): Designating Nonattainment Areas (name redacted) Specialist in Environmental Policy December 23, 2015 Congressional Research Service 7-. www.crs.gov R43953