[1] Summary of US particulate matter trends:  http://www.epa.gov/air/airtrends/2008/report/ParticlePollution.pdf

[2] Elective: Detailed Puget Sound air pollution concentrations and trends: http://www.pscleanair.org/news/library/reports/2007AQDSFinal.pdf

[3] Summary of US ozone trends: http://www.epa.gov/air/airtrends/2008/report/GroundLevelOzone.pdf

[4] Summary of US SO2, CO and NO2 trends:  http/epa.gov/air/airtrends/2008/report/NO2COSO2.pdf

[5] Brook R et al. review paper on PM cardiovascular effects and mechanisms.

[6] http://www.epa.gov/air/airtrends/aqtrnd99/pdfs/Chapter5.pdf

[7]

[8] [9] [10] [11] [12] [13]

[14]

[15]

[16] Elective

[17]

[18]

[19]

[21]

[22]

[26]