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

Marshall, Julian; Riley, William J.; McKone, Thomas E.; Nazaroff, William W.

doi:10.1016/s1352-2310(03)00269-3

Cited by 95 publications

(69 citation statements)

References 39 publications

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“…Excluding the bottom 10% of the ozone inhalation intake rate distribution, values (mg d À1 ) for the mean, Std, GM, and GSD are 133, 176, 83, and 2.7, respectively. work and a separate estimate in Marshall et al (2003). Both estimates are approximate rather than definitive.…”

Section: Article In Pressmentioning

confidence: 96%

“…3 presents the average diurnal breathing rate profile for this investigation. To our knowledge, there are only two extant estimates for this diurnal profile (Mortola, 2004(Mortola, , 2006 b Based on Flachsbart (1995Flachsbart ( , 1999, Rodes et al (1998), andMarshall et al (2003). ''Tri(2,4,6)'' indicates a triangular probability distribution; the lowest value of the distribution is 2; the most common value is 4; the maximum value is 6. c Penetration efficiency, P, is based on Ozkaynak et al (1996) and Riley et al (2002).…”

Section: Inhalation Intake Ratesmentioning

confidence: 99%

“…e Based on CARB (2004), Flachsbart (1995Flachsbart ( , 1999, Rodes et al (1998), andMarshall et al (2003). f Based on Chan et al (1991).…”

Section: Inhalation Intake Ratesmentioning

confidence: 99%

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Inhalation intake of ambient air pollution in California's South Coast Air Basin

Marshall

Granvold

Hoats

et al. 2006

Atmospheric Environment

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Reliable estimates of inhalation intake of air pollution and its distribution among a specified population are important for environmental epidemiology, health risk assessment, urban planning, and environmental policy. We computed distributional characteristics of the inhalation intake of five pollutants for a group of $25,000 people ($29,000 persondays) living in California's South Coast Air Basin. Our approach incorporates four main inputs: temporally resolved information about people's location (latitude and longitude), microenvironment, and activity level; temporally and spatially explicit model determinations of ambient concentrations; stochastically determined microenvironmental adjustment factors relating the exposure concentration to the ambient concentration; and, age-, gender-, and activityspecific breathing rates. Our study is restricted to pollutants of outdoor origin, i.e. it does not incorporate intake in a microenvironment from direct emissions into that microenvironment. Median estimated inhalation intake rates (mg d À1 ) are 53 for benzene, 5.1 for 1,3-butadiene, 8.7 Â 10 À4 for hexavalent chromium in fine particulate matter (Cr-PM 2.5 ), 30 for diesel fine particulate matter (DPM 2.5 ), and 68 for ozone. For the four primary pollutants studied, estimated median intake rates are higher for non-whites and for individuals in low-income households than for the population as a whole. For ozone, a secondary pollutant, the reverse is true. Accounting for microenvironmental adjustment factors, population mobility and temporal correlations between pollutant concentrations and breathing rates affects the estimated inhalation intake by 40% on average. The approach presented here could be extended to quantify the impact on intakes and intake distributions of proposed changes in emissions, air quality, and urban infrastructure. r

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Section: Article In Pressmentioning

confidence: 96%

Section: Inhalation Intake Ratesmentioning

confidence: 99%

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Inhalation intake of ambient air pollution in California's South Coast Air Basin

Marshall

Granvold

Hoats

et al. 2006

Atmospheric Environment

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“…[2][3][4][5] In-vehicle exposure can be a significant part of personal total exposure to ambient particulates. 6,7 Automobile exhaust is a major source of ambient PM and black carbon (BC), and in-vehicle exposure to PM can be higher than ambient concentration. 8 PM 10 concentrations inside buses and trams have exceeded the ambient level by 3-5 times in Munich, Germany.…”

Section: Introductionmentioning

confidence: 99%

In-Vehicle Exposures to Particulate Matter and Black Carbon

Lee

Sohn

Putti

2010

Journal of the Air & Waste Management Association

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In-vehicle exposures to particulate matter (PM) and black carbon (BC) can be a significant part of personal total exposure. The purpose of this study was to identify determinants of the in-vehicle pollutant level. This study measured in-vehicle exposure to PM number concentrations using an aerosol spectrometer and BC concentration by an aethalometer. The measurement was repeated 3 times a day for 13 consecutive days in May 2007 while a vehicle was driven on a 1-hr predetermined route in Lexington, KY. The vehicle's windows were closed, its fan was operated at the lowest setting, and air conditioning and heating were off. The average speed of all runs was 37 Ϯ 5.8 km/hr. Arithmetic mean PM 1 (particle sizes Յ1 m in aerodynamic diameter) number and BC concentrations were 286 #/cm 3 (morning, 302 #/cm 3 ; afternoon, 270 #/cm 3 ; evening, 287 #/cm 3 ) and 1.9 g/m 3 (morning, 2.5 g/m 3 ; afternoon, 1.6 g/m 3 ; evening, 1.5 g/m 3 ), respectively. Average PM and BC concentrations increased during weekdays and decreased during weekends, and PM 1 number and BC concentrations were highest in the morning. Particle size distribution for PM 1 did not differ with time of day, but the concentration of PM 1-10 (particle sizes between 1 and 10 m in aerodynamic diameter) was higher in the evening and lower in the morning. Peak PM 1 number concentrations were observed when the test vehicle approached busy crossroads. In-vehicle PM and BC concentrations were associated with time of the day and location, whereas the in-vehicle 1-hr PM number concentrations were closely associated with distant ambient PM 2.5 (particle sizes Յ2.5 m in aerodynamic diameter) concentrations measured at a stationary monitoring site. The findings suggested that in-vehicle exposure is associated with surrounding traffic. INTRODUCTIONA relationship between exposure to fine particles and adverse health effects, including cardiovascular and pulmonary diseases, has been suggested by several epidemiologic studies. 1 In some studies, particulate matter (PM) less than or equal to 2.5 m in aerodynamic diameter (PM 2.5 ) has been associated with increased hospital admissions, emergency room visits for heart and lung disease, increased respiratory symptoms and disease, and decreased lung function. [2][3][4][5] In-vehicle exposure can be a significant part of personal total exposure to ambient particulates. 6,7 Automobile exhaust is a major source of ambient PM and black carbon (BC), and in-vehicle exposure to PM can be higher than ambient concentration. 8 PM 10 concentrations inside buses and trams have exceeded the ambient level by 3-5 times in Munich, Germany. 8 Such higher concentrations may be due to a vehicle's proximity to relatively undiluted emissions from other vehicles and the typically high air-exchange rate inside vehicles. 9 Although a person may spend relatively short time in a transportation environment, high exposures during short transportation periods may be more important for health effects than 24 hr exposures. 10,11 During school bus comm...

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“…26 Studies have also determined that exposures at hourly or minute scales experienced in microenvironments with elevated PM levels may lead to a significant portion of an individual's daily exposure. [27][28][29][30][31] Such findings call into question the suitability of the current EPA 24-hr and annual standards in protecting populations from acute peak exposure periods that occur in subdaily time frames. This points to the importance of understanding the degree to which 24-hr and annual PM 2.5 standards can control subdaily peak levels and provide an adequate margin of safety.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Primary Fine Particle National Ambient Air Quality Standard Metrics

Johnson¹,

Graham²

2006

Journal of the Air & Waste Management Association

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In accordance with the Clean Air Act, the U.S. Environmental Protection Agency (EPA) is currently reviewing its National Ambient Air Quality Standards for particulate matter, which are required to provide an adequate margin of safety to populations, including susceptible subgroups. Based on the latest scientific, health, and technical information about particle pollution, EPA staff recommends establishing more protective health-based fine particle standards. Since the last standards review, epidemiologic studies have continued to find associations between short-term and long-term exposure to particulate matter and cardiopulmonary morbidity and mortality at current pollution levels. This study analyzed the spatial and temporal variability of fine particulate (PM 2.5 ) monitoring data for the Northeast and the continental United States to assess the protectiveness of various levels, forms, and combinations of 24-hr and annual health-based standards currently recommended by EPA staff and the Clean Air Scientific Advisory Committee. Recommended standards have the potential for modest or substantial increases in protection in the Northeast, ranging from an additional 13-83% of the population of the region who are living in areas not likely to meet new standards and thereby benefiting from compliance with more protective air pollution controls. Within recommended standard ranges, an optimal 24-hr (98th percentile)/annual standard suite occurs at 30/12 g/m 3 , providing short-and long-term health protection for a substantial percentage of both Northeast (84%) and U.S. (78%) populations. In addition, the Northeast region will not benefit as widely as the nation as a whole if less stringent standards are selected. Should the 24-hr (98th percentile) standard be set at 35 g/m 3 , Northeast and U.S. populations will receive 16 -48% and 7-17% less protection than a 30 g/m 3 standard, respectively, depending on the level of the annual standard. A 30/12 g/m 3 standard suite also provides nearly equivalent 24-hr and annual control of PM 2.5 distributions across the United States, thereby ensuring a more uniform and consistent level of protection than unmatched or "controlling" and "backstop" standards. This could occur even within EPA staff's recommended range of standard suites, where 22-43% of the monitors in the country could meet a controlling standard but fail to meet the combined backstop standard, resulting in inconsistent short-and long-term protection across the country. An equivalent standards combination of 30/12 g/m 3 would minimize the wide variation of protectiveness of 24-hr and annual PM 2.5 concentrations. Furthermore, given recent associations of subdaily exposures and acute adverse health effects, in the absence of a subdaily averaging metric, a stringent 24-hr standard will more effectively control maximum hourly and multihourly peak concentrations than a weaker standard.

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

Cited by 95 publications

References 39 publications

Inhalation intake of ambient air pollution in California's South Coast Air Basin

Inhalation intake of ambient air pollution in California's South Coast Air Basin

In-Vehicle Exposures to Particulate Matter and Black Carbon

Analysis of Primary Fine Particle National Ambient Air Quality Standard Metrics

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