Tiny particles can zoom through human lungs up to two times faster and penetrate more deeply than assumed before, a University of Delaware scientist says. Children and the elderly are at even greater risk. Scientists from around the world have gathered in Atlanta this month to determine the best ways to measure this fine particulate matter that is polluting the nation's air, particularly in large urban areas. Atlanta's air pollution problems have halted several new highway construction projects that officials feared would increase already dangerous city smog levels. Particulate matter, which is federally regulated, is created by the burning of coal and oil.
Numerous studies link it to serious health problems.
Fine particulate matter, called PM 2.5 because it is less than 2.5 microns in diameter - about 30 times smaller than the diameter of a human hair, includes soot, dust, aerosols, metals and sulfates. These particles emitted by vehicles, factories and industrial facilities contribute to the smog so common in American cities. We need to do this to understand the health effects and the sources, and to monitor compliance with EPA standards. Smog causes problems in cities across the U.S., sometimes in hard to predict locales. In the nation's smog capital, Los Angeles residents are now enjoying one of their least polluted summers ever.