Environmental Engineering Reference
In-Depth Information
6.2.3  i ndoor  a erosol  s ource  a PPortionMent
Indoor source apportionment is critical to understanding the links between PM exposure and health
effects, and investigators have used approaches that are similar to those used for PM in outdoor air
(Section 6.1.3.2). This review of indoor PM sources began by mentioning that the PTEAM found
that smoking and cooking were the largest contributors to indoor particles, after outdoor air. To
estimate the contribution of individual sources to indoor and personal PM concentrations found
in the PTEAM study, Ozkaynak et al. (1996) used a CMB approach, along with a simple model
of indoor pollutant behavior (Koutrakis and Briggs, 1992). They started with mass and elemental
concentration data for outdoor, indoor, and personal PM 2.5 and PM 10 . Indoor source proiles were
derived from reviewing participants' activity reports and multiple linear regression. More recently,
Arhami et al. (2010) applied a CMB approach to apportion what they called quasi-ultraine PM in
retirement homes in southern California. Using trafic markers (hopanes, stearanes, and polycyclic
aromatic hydrocarbons) they concluded that the main source of indoor particles <250 nm was traf-
ic. They also found that alkanes and alkanoic acids indicated the presence of indoor PM sources.
An advantage of the factor analysis approach is that it does not require a priori knowledge of
indoor processes. Yakovleva et al. (1999) used PMF to apportion sources of personal exposure to PM,
based on PTEAM data. They identiied ive source proiles that inluenced personal PM 10 exposure:
motor vehicles, secondary sulfate, personal activities, resuspended indoor soil, and indoor soil. For
example, Figure 6.7 compares the contributions of these factors to the participants' reported activities.
180
No indoor cooking reported
160
140
120
100
80
60
40
20
0
Indoor cooking
(a)
180
160
140
120
100
80
60
40
No vacuuming reported
Vacuuming
20
0
180
160
140
120
100
80
(b)
Vehicle was started in the garage attached to house
Vehicle was not started in the garage
60
40
20
0
Motor
vehicles
Indoor
soll
Personal
activities
Resuspended
indoor soll
Secondary
sulfate
PM 10
(c)
FIGURE 6.7  PMF source apportionment for PTEAM personal PM 10 : The histograms show the contribu-
tions from each computed source factor compared to activity logs: (a) indoor cooking; (b) vacuuming; (c)
starting a vehicle in an attached garage. (From Yakovleva, E. et al., Environ. Sci. Technol ., 33, 3645, 1999.
With permission.)
 
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