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Title
Do the age of homes in Sacramento County Correlate to Poor Wintertime
Air Quality?
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Author
Janice Lam
American River College, Geography 350: Data Acquisition in GIS; Spring 2010
Contact Information (lamj3@arc.losrios.edu)
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Abstract
During the winter time in Sacramento
County, PM2.5 becomes
the main air quality pollution problem.
Wood smoke is the greatest emission during the months of November
through February. Through a simplified
analysis of attempting to find a correlation between the age of homes/frequency
of homes built after year 2000, a relationship could not be found trying to
relate the two information. While the
air quality monitoring site Del Paso Manor had the highest percentage of
“newer” homes within a 3 mile radius, it also had the highest PM2.5
concentrations between the years of 2005-2007.
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Introduction
Air pollution problems in Sacramento
County can be must be
dealt with differently during different times of the year. During the summer
time month, ground level ozone causes most of the summer time air quality
problems. During the winter months, fine particulate matter pollution (PM2.5)
becomes the issue.
There are many contributing sources to PM2.5 emissions in the Sacramento County, such as emissions from diesel
trucks, unpaved road dusts, wildfires. One of the main contributing
factors for PM2.5 for the Sacramento
County is emission from
wood burning devices. Many of these wood-burning devices were installed
in older homes, while the newer homes now come with gas burning fireplaces.
Current rule already in place includes a no burn program during days
when air quality is forecasted to be poor.
The hypothesis here is whether these ages of homes, since
older homes tend to have a traditional fireplace or woodstoves while newer
construction homes tend to have gas fireplaces which do not emit smoke. This project will attempt to investigate
is whether the age of homes in the county can be correlated to poor air
quality during the wintertime. Whether or not a targeted program
towards neighborhoods would result in an air quality benefit -to see if there
is a correlation between the age of neighborhoods and the local air quality.
The general approach will be to obtain household age information from
the US
census and the Sacramento GIS database and correlate it with wintertime air
quality PM2.5 values to see whether or not there are distinct and significant
biases towards one neighborhood versus another.
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Background
Particulate matter 2.5 (PM2.5) is the term
for solid or liquid particles found in the air. Some particles are large or
dark enough to be seen with the naked eye and can take the form as soot or
smoke. Others are so small they can be detected only with an electron
microscope. Because particles originate from a variety of sources (cars,
buses, diesel trucks (mobile), fireplaces, woodstoves, power plants
(stationary), etc.), their chemical and physical compositions vary widely. Particulate matter can
be directly emitted or can be formed in the atmosphere when gaseous
pollutants such as Sulfur dioxide (SO2) and Nitrogen dioxides
(NOx) react to form fine particles. In
1997, the PM NAAQS, the EPA supplemented its regulations on PM10 with new
regulations on PM2.5. The terms "fine" and "coarse" were
originally intended to apply to the two major atmospheric particle
distributions which overlap in the size range between 1 and 3 microns. Now,
"fine" has been defined by EPA as PM2.5 and "coarse" as
PM10–2.5. However, PM2.5 may contain, in addition to the fine-particle mode,
some of the smaller sized "coarse" particles. See Figure 1 for
actual size of a PM2.5 particle.
Figure 1: Diagram of Particulate
Matter 2.5
Sacramento
County
exceeds state or federal health standards for fine particle air pollution
(PM2.5). The burning of wood or other solid
fuel constitutes the single largest source of fine
particle emissions for this region
during the wintertime.
During the Sacramento Air Quality
Management District’s Rule 421, Mandatory Episodic Curtailment of Wood and
other Solid fuel burning analysis in 2009
the District contracted with Sonoma Technology Institute to conduct analysis
on whether or not banning wood burning on poor air quality days would improve
and help the region meet PM2.5 federal air quality standards. They did three different analyses, a
cluster analysis, a chemical mass balance (CMB) modeling and numerical
modeling. Two of these analyses
(Cluster analysis and numerical modeling) involve weather information, and
its conduciveness to air quality data.
While the CMB modeling indicated and speciated the emissions that
would attribute to the amount of wood smoke on “high” PM2.5 days. Neither of these analyses examined outside
of the meteorology aspect of where these emissions could have been from.
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Methods
The approach used to test this hypothesis will be to
gather census data from the Census Bureau database on the effective year the
homes were built, and the relative statistics to show if there is a
correlation between high PM2.5 concentrations and the years the homes were
built. By using ArcGIS to combine
housing data and the location of the air quality monitoring sites, the
frequency distribution, and the average age of the homes within a certain
distance from the air quality monitoring site can be used to roughly deduce
whether or not there is an indication of newer neighborhoods with the newer
fireplaces can produce better air quality.
There are three air quality
monitoring sites that will be used for this project; Del Paso Manor, T street, and Health Department site. These sites have been sited by the local
air quality agency to represent the ambient air quality in Sacramento County
(Figure 1), other pollutant data is also collected at these sites such as
ozone, CO2, and NOx. The three years
that air quality data that is used for this project are years 2005-2007. The reason for using a little bit of an
older dataset is because during the summer of 2008, there were summer PM2.5
anomalies due to the wildfires that occurred in California. The air quality statistics that will be
used for this basis is the design value for the air quality site (the
calculated value used to compare one air quality monitoring site to another,
calculated using ambient air quality data) The statistic from the homes data
will be the frequency of newer homes near the three sites. The average age of homes would not be
helpful in this cause because some homes that are much older (ej 1800 vs
1950s) may skew the average. Three mile buffer zones were created
for each monitoring site. This allows for calm low wind speeds days but still
being on a somewhat local scale.
Figure 2. Sacramento County
Monitoring Stations
Figure 3: Del Paso Manor Air Quality
Site with Buffers of 3 Miles
Figure 4: Health Department Air
Monitoring Site with 3 mile Buffers
Figure 5: T street Air Quality
Monitoring Site 3 Mile Buffer
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Results & Analysis
The percentage of “newer” homes (defined as built after
year 2000) to “older” homes (homes built before 2000) at each monitoring
station did not vary greatly. Table 2
shows the percentages of homes that were built after the year 2000 at each of
the monitoring stations within a 3 mile radius.
Table1: Percentage of Homes with Effective Date year 2000 or Above
There does not seem to be a strong correlation between the
percentages of homes that were built after year 2000 and ambient PM2.5 air
quality concentrations. While DPM does
have the highest percentages of homes built after 2000, it shows in Table 1
that it is also the highest design value site in the Sacramento County.
On average, the air quality data shows that the design
value at the Health Department Air Quality site is lower than the other two
sites consistently through 2005 to 2007, as shown in Table 1. In addition to that, there were on average
lower number of days that exceeded the national PM2.5 24-hour standard than
of the Del Paso Manor Site and the T
street monitoring site in 2007.
Table 2: Air Quality Monitoring Site Design Values
Results from the analysis shows that the frequency of
newer homes within 3 miles of the Health Department Air Monitoring Site is not
greater than of the Del Paso Manor Site and the T street Air Monitoring Site.
Refer to Figures 5-7. See Figures 6-8
for the frequency of the newer homes at each of the three monitoring site
locations. As stated earlier, the
percentage of homes that were built year 2000 or after near the Del Paso
Manor Site is greater than of the other two sites.
Figure 6: Health Department
Figure 7: T street
Figure 8: Del Paso Manor
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Conclusion
It could not be concluded that there
is a correlation between the age of homes and the ambient PM2.5 using the
method stated in this analysis. The
analysis did not show that if a neighborhood had a higher percentage of newer
homes that the local air quality for PM2.5 would be any better than of an
older neighborhood. This was a
simplified method that did not consider meteorology such as wind direction or
wind speed, and information on the actual wood burning behaviors within the
certain area.
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References
California Air
Resources Board, 2010. website: http://www.arb.ca.gov/adam/welcome.html,
accessed April 1, 2010
Environmental Protection Agency, 2010 website: http://www.epa.gov/air/particlepollution/basic.html,
accessed May 5, 2010.
Factfinder
Census website: http://factfinder.census.gov/servlet/DatasetMainPageServlet?_program=ACS&_submenuId=&_lang=en&_ts=,
accessed April 1, 2010
J.Chow,
J.Watson, L-W. Chen, D. Lowenthal, R.Countess, S.Countess, 2004. Temporal and
Spatial Variations of PM2.5 During CRPAQS Winter Intensives
SMAQMD, 2008. Rule 421, Mandatory Episodic
Curtailment of Wood and Other Solid Fuel Burning Proposed Amendments
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