Aerosol Chemistry and Physics - Aerosols: Measurement, Dosimetry, and Health Effects - page 146

6.2.1.6 Unvented Kerosene Heaters and Lamps
Although the sale of portable UKHs has been banned in some U.S. states, at the end of the 20th century,
over a million units were sold in the United States each year (Manuel, 1999). Carbon monoxide poison-
ing and ire are the greatest dangers from such heaters. Increased indoor moisture, kerosene odor, and
ine particles are also associated with their use (Traynor et al., 1983, 1986, 1990). Leaderer et al. (1999)
found UKHs in about one third of over 200 homes in Virginia and Connecticut whose indoor air was
monitored during the winters of 1995-1998. They reported that UKHs added about 40 μg m −3 of PM 2.5
and 15 μg m −3 particulate SO 4 = to background indoor levels of 18 and 2 μg m −3 , respectively. They also
found elevated levels of nitrous acid (HONO) in homes where UKH or gas stoves were operated. In an
earlier chamber study, Leaderer et al. (1990) measured emission factors (for K-1 fuel with 0.04% S) of
33-392 and 15-227 μg g −1 for PM 2.5 and SO 4 = , respectively, from operation of four types of UKH. The
sulfate results suggest that UKHs are a major indoor source of ine acidic aerosol. Leaderer et al. (1999)
found evidence that indoor ammonia was neutralized by the acidic aerosol from the UKHs.
Around 1.6 billion people, one quarter of the world's population in 2000, still used kerosene for
lighting, together with other low-grade fuels (diesel, propane, biomass) (Mills, 2005). The use of
lamps in close proximity to people and indoor environments leads to disproportionately high expo-
sures to PM. Apple et al. (2010) report PM 2.5 concentrations between 170 and 240 μg m −3 and PM 10
concentrations between 1000 and 2000 μg m −3 in kerosene-lighted street vendor kiosks in Kenya.
Those levels are ∼10 times higher than 24 h guidelines by the WHO.

6.2.2 H uMan a ctivities and c onsuMer P roducts

6.2.2.1 Pesticides
Organophosphates, chlorinated compounds, and permethrins have been found in indoor PM and
dust (Rudel et al., 2003, and references therein; Becker et al., 2002; Berger-Preiss et al., 2002; Rudel
et al., 2002 ). Foot trafic is thought to be a major vector of pesticide transport from outdoor soil
particles (Nishioka et al., 1996). Indoor sources of particulate pesticides include lea powder and
aerosolized insecticides, among others. Dry lea powder contributes to the coarse particle fraction
(2.5-10 μm diameter, authors' comparison to ine powder of known mass size distribution), whereas
sprays deliver semi-volatile agents in liquid particles that settle on surfaces or evaporate within min-
utes (Bukowski and Meyer, 1995). Semi-volatile pesticides like chlorpyrifos, a termiticide, continue
to evaporate from indoor surfaces such as carpet for weeks or longer (Stout and Mason, 2003, and
references therein).

6.2.2.2 Air Fresheners and Fragrances
Most products sold as air fresheners include fragrances that increase concentrations of VOCs
indoors. Frequently, the fragrant compounds include terpenoids such as α-pinene from pine oil or
d-limonene from citrus oils. These terpenoids can react with ozone to produce ine PM (Hoffmann
et al., 1997; Kamens et al., 1999; Destaillats et al., 2006a; Singer et al., 2006a). Since building enve-
lopes scrub only about half of the iniltrating outdoor ozone, indoor secondary aerosol formation
probably occurs to a larger extent than previously recognized (Weschler and Shields, 1997). This is
exacerbated by the use of air cleaners that generate ozone (Hubbard et al., 2005).

6.2.2.3 Walking
In their study of real-time particle size distributions in four nonsmoking houses in Boston, Massachusetts,
Abt et al. (2000) found that movements of people increased indoor concentrations of large particles
(∼4 μm median diameter) ive times more than they increased concentrations of ine particles (∼0.2 μm).
Ferro et al. (2002) found that simply walking around indoors increased personal exposure to both ine
and coarse particles. Figure 6.5 shows real-time PM 5 proiles obtained by Ferro et al. The major con-
tributor is resuspension of settled dust from loors and carpets (Thatcher and Layton, 1995).