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Detroit, MI, United States

Ganguly R.,University of Michigan | Batterman S.,University of Michigan | Brakefield-Caldwell W.,Community Action Against Asthma
Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA | Year: 2012

Exposure to traffic-related air pollutants has been associated with adverse health effects such as reduced lung function and asthma, deficits in growth of lung functions and cancer. Epidemiological studies have shown adverse health effects for populations living near major roads and highways, with children suffering from asthma being at particularly high risk. Several health effects studies have used geographic information systems to investigate associations between air pollutants and health effects, e.g., the distance between residences and emission sources such as highways and industry is perhaps the most common exposure indicator. Such indicators require that locations of participants' homes are accurately geocoded, and that the road network and traffic patterns are accurately characterized. Errors in positional (geocoding) errors for either residences or sources can lead to exposure misclassification. The magnitude of positional errors and the corresponding exposure estimates for near road exposures that result from common geocoding approaches was investigated. Such errors were characterized in terms of both distance and air pollutant concentration, the latter derived from dispersion model predictions of both annual and daily averages. This work was applied to a case study, an ongoing air pollution epidemiological study in Detroit, Michigan called the Near-road Exposures and effects of urban air pollutants Study, which was designed to examine the relationship between near-roadway exposures to air pollutants and respiratory outcomes in a cohort of asthmatic children living near major roadways. The study enrolled 139 children, ages 6-14, based on the proximity of their home to major roadways (> 90,000 vehicles/day) that carried different amounts of diesel traffic. Due to children moving during the study, a total of 160 homes were considered. The average error over the 160 residences was 31.3 m. The distance bin with the highest error of 40.3 m was the 200-500 m bin; the lowest error of 25.5 m was the 0-100 m bin. The maximum error of 146 m was found in the 100-200 m. The effect of positional errors depended on the spatial gradient of the pollutant concentration. For traffic-related pollutants, positional errors can be important near roads where gradients are steep. Errors in the direction perpendicular to the road may make the largest difference. This is an abstract of a paper presented at the 106th AWMA Annual Conference and Exhibition (Chicago, IL 6/25-28/2013). Source


Snyder M.G.,National Exposure Research Laboratory | Isakov V.,National Exposure Research Laboratory | Heist D.,National Exposure Research Laboratory | Arunachalam S.,University of North Carolina at Chapel Hill | And 4 more authors.
Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA | Year: 2013

Local-scale dispersion modeling is being applied in the Near-Road Exposures to Urban Air Pollutant Study (NEXUS) to estimate the exposure of asthmatic children living in Detroit, MI to traffic-generated pollutants. The NEXUS study is investigating whether children with asthma living near major roadways with high traffic have greater health impacts associated with air pollutants than those living farther away, particularly for those living near roadways with high diesel traffic. The results show that dispersion modeling with appropriate emissions estimates can capture differences between high and low diesel roadway impacts. Key modeling factors in order of importance are: NFC designation and fleet mix; meteorological conditions (especially stability), and traffic volume. In addition, local traffic measurements have the potential to significantly decrease some uncertainties in estimating traffic volume. This is an abstract of a paper presented at the 106th AWMA Annual Conference and Exhibition (Chicago, IL 6/25-28/2013). Source


Batterman S.,University of Michigan | Robins T.,University of Michigan | Lewis T.,University of Michigan | Ganguly R.,University of Michigan | And 6 more authors.
Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA | Year: 2012

The exposure metrics used in epidemiological studies that investigate traffic-related air pollutants were reviewed. Several metrics or their components were selected for in-depth analyses, and their strengths and weaknesses were described. This work was applied to a case study, an ongoing air pollution epidemiological study called the Near-road EXposures and effects of Urban air pollutants Study (NEXUS), which was designed to examine the relationship between near-roadway exposures to air pollutants and respiratory outcomes in a cohort of asthmatic children living near major roadways. The study enrolled 139 asthmatic children in Detroit, MI, aged 6-14, based on the proximity of their home to roadways having different amounts of diesel traffic. The epidemiological study was designed to contrast the health of children living within close proximity (150 m) to major roads (AADT > 90,000) to those living at least 500 m from such roads and at least 300 m from medium-sized roads (AADT > 25,000). While PM was an indicator of diesel exhaust emissions, CO concentrations had stronger correlation to traffic volume. This is an abstract of a paper presented at the 106th AWMA Annual Conference and Exhibition (Chicago, IL 6/25-28/2013). Source


Batterman S.,University of Michigan | Du L.,University of Michigan | Du L.,Donghua University | Mentz G.,University of Michigan | And 8 more authors.
Indoor Air | Year: 2012

This study, a randomized controlled trial, evaluated the effectiveness of free-standing air filters and window air conditioners (ACs) in 126 low-income households of children with asthma. Households were randomized into a control group, a group receiving a free-standing HEPA filter placed in the child's sleeping area, and a group receiving the filter and a window-mounted AC. Indoor air quality (IAQ) was monitored for week-long periods over three to four seasons. High concentrations of particulate matter (PM) and carbon dioxide were frequently seen. When IAQ was monitored, filters reduced PM levels in the child's bedroom by an average of 50%. Filter use varied greatly among households and declined over time, for example, during weeks when pollutants were monitored, filter use was initially high, averaging 84±27%, but dropped to 63±33% in subsequent seasons. In months when households were not visited, use averaged only 34±30%. Filter effectiveness did not vary in homes with central or room ACs. The study shows that measurements over multiple seasons are needed to characterize air quality and filter performance. The effectiveness of interventions using free-standing air filters depends on occupant behavior, and strategies to ensure filter use should be an integral part of interventions. © 2011 John Wiley & Sons A/S. Source


Du L.,Donghua University | Du L.,University of Michigan | Batterman S.,University of Michigan | Parker E.,University of Iowa | And 6 more authors.
Building and Environment | Year: 2011

Asthma can be exacerbated by environmental factors including airborne particulate matter (PM) and environmental tobacco smoke (ETS). We report on a study designed to characterize PM levels and the effectiveness of filters on pollutant exposures of children with asthma. 126 households with an asthmatic child in Detroit, Michigan, were recruited and randomized into control or treatment groups. Both groups received asthma education; the latter also received a free-standing high efficiency air filter placed in the child's bedroom. Information regarding the home, emission sources, and occupant activities was obtained using surveys administered to the child's caregiver and a household inspection. Over a one week period, we measured PM, carbon dioxide (CO2), environmental tobacco smoke (ETS) tracers, and air exchange rates (AERs). Filters were installed at midweek. Before filter installation, PM concentrations averaged 28 μg m-3, number concentrations averaged 70,777 and 1471 L-1 in 0.3-1.0 and 1-5 μm size ranges, respectively, and the median CO2 concentration was 1018 ppm. ETS tracers were detected in 23 of 38 homes where smoking was unrestricted and occupants included smokers and, when detected, PM concentrations were elevated by an average of 15 μg m-3. Filter use reduced PM concentrations by an average of 69-80%. Simulation models representing location conditions show that filter air flow, room volume and AERs are the key parameters affecting PM removal, however, filters can achieve substantial removal in even "worst" case applications. While PM levels in homes with asthmatic children can be high, levels can be dramatically reduced using filters. © 2011 Elsevier Ltd. Source

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