Aerosol Chemistry and Physics - Aerosols: Measurement, Dosimetry, and Health Effects - page 148

6.2.2.5 Cleaning Products
Many cleaning products contain in their formulation the same terpenoid ingredients such as
α-pinene and d-limonene described in Section 6.2.2.2 that can participate in indoor aerosol chem-
istry (Weschler and Shields, 1999; Singer et al 2006b). A comparison of personal, indoor, and out-
door exposures to VOCs in three Minnesota communities (Sexton et al., 2004) found that personal
exposure to both the aerosol precursors pinene and limonene exceeded their indoor concentrations
and that indoor concentrations exceeded outdoor concentrations.
Much less is currently known about indoor concentrations of many other semi-volatile com-
pounds that are used in cleaning products. Rudel et al. (2003) found the semi-volatile disinfectant
o-phenylphenol in indoor air and dust, along with several alkylphenols and alkylphenol ethoxyl-
ates that are ingredients of detergents. Semi-volatile compounds can adsorb onto and desorb from
indoor surfaces and even sampling media, and they were mentioned in the introduction as par-
ticipants in observed apparent violations of conservation of mass by carbonaceous components of
indoor ine mass. SVOC emissions from indoor materials and furnishings will be discussed later
in this chapter.
6.2.2.6 Portable Air Cleaners
Portable air cleaners are used widely in residential settings, as well as in the hospitality industry.
However, in some cases their pollutant removal beneits may be limited by the generation of second-
ary pollutants, particularly ozone. In turn, ozone and other concomitant reactive oxygen species can
react with terpenoids and other alkenes present in indoor air to generate SOAs. Devices that delib-
erately generate ozone are considered the most serious problem (Hubbard et al., 2005; Phillips and
Jakober, 2006). But high ozone levels and the formation of UFP in the presence of terpenoids have
also been reported during the operation of electrostatic precipitators (Alshawa et al., 2007; Jakober
and Phillips, 2008; Wensing et al., 2008).
6.2.2.7 Printers, Copiers, and Other Ofice Equipment
Particulate matter, ozone, and VOC emissions have been reported during idle and operation periods
of laser printers, ink-jet printers, and all-in-one machines that include fax, color printer, copier, and
scanner (Destaillats et al., 2008). Among those, signiicant UFP emissions were reported from laser
printers and photocopiers, often in association with ozone. Sources of these particulate emissions
include heated toner constituents and paper, and likely secondary by-products from ozone reaction
with VOCs emitted in the printing process, such as styrene. Little quantitative information is avail-
able for size-resolved characterization or chemical composition of particulate matter emitted by
ofice equipment. Schripp et al. (2008) reported particle size distribution of aerosols emitted by nine
different printers in a 1 m 3 glass environmental chamber. UFP (<100 nm) predominated in every
case, with number concentrations in the range 10 4 -10 6 cm −3 . The emission levels varied with printer
type but also with the printing cycling and page toner coverage, suggesting that various sources may
be present. Recent studies suggest that the high temperature fuser roller plays an important role as
a source of UFP (Wensing et al., 2008; He et al., 2010).
6.2.2.8 Renovation
Building renovation includes many activities that can generate large quantities of indoor particles,
including removing walls, carpets and looring materials, sanding wood, stripping paint, installing
gypsum board, and spray painting. These activities leave behind micron-sized and visible coarse
particles that are responsible for most of the particle mass (Rapp et al., 1997; Kerr and Thi, 2001),
and these can be ground to smaller respirable particles by the movement of people. However,
operations like sanding and welding generate large numbers of nanoparticles (Göhler et al., 2010;
Koponen et al., 2011). Some materials used in renovation (adhesives, sealants) emit semi-volatile
species that can adsorb to indoor dust that eventually settles everywhere in the building (Morrison
et al., 1998; Hodgson et al., 2000, 2002; Rudel et al., 2003).