Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 44 Page 45 Page 46 Page 47 Page 484 6 4 6 From 1970 to 2012, aggregate national emissions of the six common pollutants alone dropped an av- erage of 72 percent while gross domestic product grew by 219 percent. This progress reflects efforts by state, local and tribal governments; EPA; private sector companies; environmental groups and others. The emissions reductions have led to dramatic improvements in the quality of the air that we breathe. Between 1980 and 2012, national concentrations of air pollutants improved 91 percent for lead, 83 percent for carbon monoxide, 78 percent for sulfur dioxide (1-hour), 55 percent for nitrogen dioxide (annual), and 25 percent for ozone. Fine particle concentrations (24-hour) improved 37 percent and coarse particle concentrations (24-hour) improved 27 percent between 2000, when trends data begins for fine particles, and 2012. (For more trends information, see EPA’s Air Trends site.) These air quality improvements have enabled many areas of the country to meet national air quality standards set to protect public health and the environment. For example, all of the 41 areas that had unhealthy levels of carbon monoxide in 1991 now have levels that meet the health-based national air quality standard. A key reason is that the motor vehicle fleet is much cleaner because of Clean Air Act emissions standards for new motor vehicles. Airborne lead pollution, a widespread health concern before EPA phased out lead in motor vehicle gasoline under Clean Air Act authority, now meets national air quality standards in most areas of the country. State emission control measures to implement the Act, as well as EPA’s national emissions standards, have contributed to air quality improvements.