What’s In The Air That You Breathe?
Shelby Elkins, Dawn Estrella, Dr. George Murgel, and Dr. Sondra Miller
The College of Idaho
Boise School District
College of Engineering, Boise State University
Abstract: We are currently examining atmospheric particulate matter (PM) samples in areas representing varying populations—urban and rural—by comparing data from two local
sites. Atmospheric pollution is relevant to public health because it affects drinking water and respiratory health.
Background:
• PM10 are particles 10 µm or smaller in diameter
• caused by human or natural chemical processes
• small enough to be inhaled and stick in the respiratory
system
• PM2.5 are particles 2.5 µm or smaller in diameter
• created by human processes such as combustion
• can accumulate deep in the lungs due to their small
size
• Particles are further categorized by size:
• nuclei mode particles (0.005-0.1 µm)
• aerosols (0.1-2.5 µm)
• coarse particulates (2.5-10 µm)
We used two collection sites to gather samples:
• The first is on the roof of the Environmental Research
Building (ERB) on campus at Boise State University
(BSU), at approximately 2,800 feet
• The second is at the Dry Creek Experimental Watershed
(DCEW), located north of Boise in the foothills at an
approximate elevation of 5,500 feet
Above: View of the Boise Front
from the roof of the ERB at BSU
(before fire event, July 2014).
Objectives:
Data Analysis:
Methods:
Above: View of the Boise Front
from the roof of the ERB at BSU
(during fire event, July 2014).
•  Identify chemical signatures and masses of
atmospheric PM
•  Potentially pinpoint the local and regional origins of
known contaminants
•  Monitor effects on air quality due to large natural
events, both weather-related and human-caused,
during and following events
Two Micro-Orifice Uniform Deposition Impactors (MOUDI)
collected PM ranging from 0.056 µm to 18 µm in diameter
during 24-hour periods from the roof of a Boise State
building. Aluminum foil substrates collected different sizes
of particulates within the MOUDIs and were weighed to
find the mass of the particulates.
Below: Foils from the
MOUDI. The foil on the left
is from one week prior, the
foil on the right is from the
same stack, during a fire
event.
Above: MOUDI Stations on
the roof of the ERB collect
particulate matter.
Two precipitation collection sites at the DCEW, located
north of Boise, in the foothills, passively collected both wet
and dry deposition in one-week cycles. Samples were
rinsed with de-ionized water and poured through a filter in
a vacuum pump to collect any particulates.
Below left: Dry Creek filters,
before and after
processing.
Below right: Dry Creek
Collection Site.
Right: Limited wet
deposition was
collected this summer,
as Boise does not
experience much
precipitation in June or
July. The first and last
weeks showed
between two and three
times the amount of
PM as the middle
three weeks.
Left: The temperature
increase throughout July
was matched with an
increase in the mass load
of dry PM collected. Boise
experienced an influx of
smoke due to nearby fires
following July 15. There
was a visible increase in
the PM collection during
that time as well.
Left: A steady increase
in PM concentration
was collected from our
MOUDI when local fires
brought smoke to the
valley around July 15.
The total concentration
at the peak of the poor
air quality (July 17) is
three times that of the
average for the week
before and the week
after.
Acknowledgements:
• This research was partially funded by the National Science
Foundation, Grant #DMR 1359344
References:
• National Weather Service, “WFO Monthly/Daily Climate DataBoise, Idaho”. Web. 25 July 2014.
• Seinfeld, John H., and Spyros N. Pandis. Atmospheric
Chemistry and Physics. New York: Wiley and Sons, 1998. Print.
• United States Environmental Protection Agency, “Particulate
Matter (PM)”, 18 March 2014. Web. 25 July 2014.