lWhy
are particulate matter and Ozone so problematic?
What are some of the challenges to reducing
both of these pollutants?
lConsider
that in the Mid-Atlantic U.S., sulfates make up as much as 55% of PM2.5; much of this comes
from power plants. Power plants have reduced
their sulfur emissions more than 33% in this region over the past decade, yet PM2.5 concentrations remain nearly the same. How can this be?