http://www.ehponline.org/docs/2009/0800166/abstract.pdf
Teresa C. Wegesser, Kent E. Pinkerton, Jerold A. Last
doi: 10.1289/ehp.0800166 (available at http://dx.doi.org/)
Online 9 February 2009
ABSTRACT:
Background: During the last week of June in 2008, Central and Northern
California
experienced thousands of forest and brush fires, giving rise to a week of
severe firerelated
particulate air pollution throughout the region. California experienced
PM10-2.5
(coarse) and PM2.5 (fine) concentrations greatly in excess of the air
quality standards and
among the highest values reported at these stations since data have been
collected.
Objectives: These observations prompt a number of questions about the health
impact
of exposure to elevated levels of PM10-2.5 and PM2.5, and about the specific
toxicity of PM
arising from wildfires in this region.
Methods: Toxicity of PM10-2.5 and PM2.5 PM obtained during the time of peak
concentrations of smoke in the air was determined with a mouse bioassay and
compared
with PM samples collected under normal conditions from the region during the
month of
June in 2007.
Results: Concentrations of PM were not only higher during the wildfire
episodes, but
the PM was much more toxic to the lung on an equal weight basis than was PM
collected
from normal ambient air in the region. Toxicity was manifested as increased
neutrophils
and protein in lung lavage, and by histological indicators of increased cell
influx and
edema in the lung.
Conclusions: We conclude that the wildfire PM contains chemical components
that are
toxic to the lung and especially to alveolar macrophages. The wildfire PM
appear to be
more toxic to the lung than equal doses of PM collected from ambient air
from the same
region during a comparable season.
