Inhalation Transfer Factors for Air Pollution Health Risk Assessment

Lai, Alvin C.K.; Thatcher, Tracy L.; Nazaroff, William W.

doi:10.1080/10473289.2000.10464196

Cited by 102 publications

(92 citation statements)

References 15 publications

(23 reference statements)

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“…Gaussian plume equations, Lai et al (2000) calculated an iF of 4 -230 per million for outdoor sources, depending on the meteorology, population density, and urban area. Smith (1993) reported 20 Similarly, the close agreement between the intake fractions for benzene and CO also substantiates the value of the intake fraction metric.…”

Section: Discussionmentioning

confidence: 99%

“…The intake fraction for benzene is slightly higher than for CO due to the slightly 12 increased exposures from attached garages, but this difference is small compared to the seasonal variability for both benzene and CO. Note that we have used a population breathing rate of 12.2 m 3 day -1 rather than the adult breathing rate of 19 -20 m 3 day -1 used in most previous intake fraction research (e.g., Lai et al, 2000;Nigge, 2001;Evans et al, 2002). If we were to use a breathing rate of 20 m 3 day -1 , our results would increase to 76 per million and 79 per million for CO and benzene, respectively.…”

Section: Intake Fraction Within the Socabmentioning

confidence: 99%

“…The iF depends on factors such as source type (e.g., indoor versus outdoor, urban versus rural) and pollutant fate and transport (e.g., reaction and removal rates, importance of multi-5 media, multi-pathway exposures) (Bennett et al, 2002;Evans et al, 2002;Lai et al, 2000). Two pollutants emitted from the same source with identical fate and transport characteristics will have identical intake fractions.…”

Section: Intake Fractionmentioning

confidence: 99%

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Intake fraction of primary pollutants: motor vehicle emissions in the South Coast Air Basin

Marshall

Riley

McKone

et al. 2003

Atmospheric Environment

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The intake fraction is defined for a specific species and emission source as the ratio of attributable population intake to total emissions. Focusing on California's South Coast Air Basin (SoCAB) as a case study, we combine ambient monitoring data with time-activity patterns to estimate the population intake of carbon monoxide and benzene emitted from motor vehicles during 1996 -1999. In addition to exposures to ambient concentrations, three microenvironments are considered in which the exposure concentration of motor vehicle emissions is higher than in ambient air: in and near vehicles, inside a building that is near a freeway, and inside a residence with an attached garage. Incorporating data on motor vehicle emissions estimated by the EMFAC2000 model, we estimate that the 15 million people in the Submitted to Atmospheric Environment January 27, 2003 2 SoCAB inhale 0.003 -0.009% (34 -85 per million with a best estimate of 47 per million) of primary, nonreactive compounds emitted into the basin by motor vehicles. This population intake of primary motor vehicle emissions is approximately 50% higher than the average ambient concentration times the average breathing rate, owing to higher concentrations in the three microenvironments and also to the temporal and spatial correlation among breathing rates, concentrations, and population densities. The approach demonstrated here can inform policy decisions requiring a metric of population exposure to airborne pollutants.

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Section: Discussionmentioning

confidence: 99%

Section: Intake Fraction Within the Socabmentioning

confidence: 99%

Section: Intake Fractionmentioning

confidence: 99%

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Intake fraction of primary pollutants: motor vehicle emissions in the South Coast Air Basin

Marshall

Riley

McKone

et al. 2003

Atmospheric Environment

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“…To understand the importance of characterizing air pollution in rural kitchens in which small-scale combustion of solid fuels routinely transpires, consider that inhalation intake per unit emission is two to three orders of magnitude higher for indoor combustion sources than for outdoor sources (Smith, 1988;Wallace, 1996;Lai et al, 2000;Evans et al, 2002). Compounding the problem of greater intake for indoor sources is that solid fuel/stove combinations are two to three orders of magnitude more polluting than their gas counterparts: for example, a study of emissions factors from 28 Chinese fuel-stove combinations indicates that solid fuels typically emit 10-100 g products of incomplete combustion (PICs) per MJ of delivered energy, whereas Chinese stoves burning liquid petroleum gas (LPG), coal gas, or natural gas emit o0.03 g-PIC/MJ (Zhang et al, 2000).…”

Section: Indoor Air Quality In Rural Kitchens: a Public Health Prioritymentioning

confidence: 99%

Field performance of a nephelometer in rural kitchens: effects of high humidity excursions and correlations to gravimetric analyses

Fischer¹,

Koshland²

2006

J Expo Sci Environ Epidemiol

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Rural kitchens of solid-fuel burning households constitute the microenvironment responsible for the majority of human exposures to health-damaging air pollutants, particularly respirable particles and carbon monoxide. Portable nephelometers facilitate cheaper, more precise, time-resolved characterization of particles in rural homes than are attainable by gravitational methods alone. However, field performance of nephelometers must contend with aerosols that are highly variable in terms of chemical content, size, and relative humidity. Previous field validations of nephelometer performance in residential settings explore relatively low particle concentrations, with the vast majority of 24-h average gravitational PM 2.5 concentrations falling below 40 mg/m 3 . We investigate relationships between 24-h gravitational particle measurements and nephelometric data logged by the personal DataRAM (pDR) in highly polluted rural Chinese kitchens, where gravitationally determined 24-h average respirable particle concentrations were as high as 700 mg/m 3 . We find that where relative humidity remained below 95%, nephelometric response was strongly linear despite complex mixtures of aerosols and variable ambient conditions. Where 95% relative humidity was exceeded for even a brief duration, nephelometrically determined 24-h mean particle concentrations were nonsystematically distorted relative to gravitational data, and neither concurrent relative humidity measurements nor use of robust statistical measures of central tendency offered means of correction. This nonsystematic distortion is particularly problematic for rural exposure assessment studies, which emphasize upper quantiles of time-resolved particle measurements within 24-h samples. Precise, accurate interpretation of nephelometrically resolved short-term particle concentrations requires calibration based on short-term gravitational sampling.

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“…For example, Smith (1993) estimated a US population intake fraction of 2400 ppm for indoor exposure to SHS particles. By applying an indoor air quality model and assuming receptors occupy fixed locations in individual rooms, Lai et al (2000) estimated individual intake fractions for residential exposure to a nonreactive gas of approximately 1500−2000 ppm.…”

Section: Effect Of Human Activitymentioning

confidence: 99%

Modeling residential exposure to secondhand tobacco smoke

Klepeis

Nazaroff

2006

Atmospheric Environment

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We apply a simulation model to explore the effect of a house's multicompartment character on a nonsmoker's inhalation exposure to secondhand tobacco smoke (SHS). The model tracks the minute-by-minute movement of people and pollutants among multiple zones of a residence and generates SHS pollutant profiles for each room in response to room-specific smoking patterns. In applying the model, we consider SHS emissions of airborne particles, nicotine, and carbon monoxide in two hypothetical houses, one with a typical 4-room layout and one dominated by a single large space. We use scripted patterns of room-to-room occupant movement and a cohort of 5,000 activity patterns sampled from a US nationwide survey. The results for scripted and cohort simulation trials indicate that the multicompartment nature of homes, manifested as inter-room differences in pollutant levels and the movement of people among zones, can cause substantial variation in nonsmoker SHS exposure.

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Inhalation Transfer Factors for Air Pollution Health Risk Assessment

Abstract: To facilitate routine health risk assessments, we develop

Cited by 102 publications

References 15 publications

Intake fraction of primary pollutants: motor vehicle emissions in the South Coast Air Basin

Intake fraction of primary pollutants: motor vehicle emissions in the South Coast Air Basin

Field performance of a nephelometer in rural kitchens: effects of high humidity excursions and correlations to gravimetric analyses

Modeling residential exposure to secondhand tobacco smoke

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