HI ALEX YOURE MY FAVORITE IN THIS WHOLE ENTIRE WORLD!! (and I like him so much oh my gosh) Chapter 15 Notes Trini Soza Air pollution The introduction of chemicals, particulate matter, or microorganisms into the atmosphere at concentrations high enough to harm plants, animals, and materials such as buildings, or to alter ecosystems - Air pollution is the most widespread environmental damage. - 147 million metric tons of air pollution released each year by the US. - The world releases about 2 billion metric tons a year. - Air quality has improved over the past 20 years in developed countries. - Developing countries however have higher air pollution sometimes ten times higher than the pollution levels considered safe for human health. Natural Air pollution: