PHOENIX — A health watch for particulates in the air is in effect Friday
for Maricopa County.
Environmental quality regulators said open burning and use of wood burning
fireplaces are generally prohibited. People with respiratory problems are
advised to avoid heavy or prolonged outdoor exertion.
Particulates are extremely small solid particles and liquid droplets that come
from automobile exhaust, burning and dust. High levels typically occur when the
air is stagnant.