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30.
Correlating bioaerosol load with PM2.5 and PM10cf concentrations:
a comparison between natural desert and urban fringe aerosols
Justin
Boreson(a), Ann M. Dillner(a,b), and Jordan
Peccia(a)*
(a)Department
of Civil and Environmental Engineering, Arizona State University,
Tempe, AZ 85287-5306
*(b)Department of Chemical and Materials Engineering, Arizona
State University, Tempe, AZ 85287-6006
Seasonal allergies and microbial mediated respiratory
diseases can coincide with elevated particulate matter concentrations.
Many of these allergic and asthmatic responses may be enhanced
when chemical and biological constituents of particulate matter
are combined together. Because of these associations and also
the regulatory and health related interests of monitoring PM2.5,
separately from total PM10, the biological loading between the
fine (dp<2.5?m) and coarse (2.5?m<dp<10?m) size ranges
of particulate matter was studied. To investigate spatial and
seasonal differences, 24-hour fine and coarse particulate matter
fractions were collected at a natural desert area and an urban
fringe site located in the expanding Phoenix, Arizona metropolitan
area during winter, spring, and summer seasons. Elemental carbon
and inorganic ions were measured to determine the relative influence
that anthropogenic sources, such as traffic, had at the sampling
sites. Total protein concentration was used as a surrogate measure
of total biological concentration within the PM2.5 and PM10cf
(coarse fraction) size ranges.
In all seasons, coarse protein concentrations at
the urban fringe was consistently higher than concentrations at
the natural desert. When high anthropogenic particulate matter
events were separated from the data set, a positive significant
correlation (p<0.05) was found between protein and total mass
and protein and organic matter in the course fraction, but not
in the fine fraction. An 18S rDNA clone library was developed
from PM10 aerosol samples to characterize the type and diversity
of airborne biological material (nonbacterial) existing in ambient
particulate matter. Both sites contained allergenic organisms.
Some groups of organisms were exclusive to only one of the sites.
The natural desert contained more species of Basidiomycota fungi
and the urban fringe contained more species of green plants (many
of agricultural origin), suggesting that the biological loading
at each site was different due to local influences.
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