56 research outputs found

    Wind-tunnel study of LPC Mandalay, Las Colinas, Texas

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    CER85-86JAP-JEC-WWL16.CER85-86JAP-JEC-WWL16a.Includes bibliographical references.February 1986.CSU Project 2-96600.For Lincoln Property Company through Brockette & Associates, Inc

    Wind tunnel study of inpatient replacement building, Massachusetts General Hospital, Boston

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    CER85-86JAP-JEC-WWL5.Includes bibliographical references (page 26).August 1985.CSU Project 2-96290.For McNamara/Salvia Consulting Engineers

    Wind tunnel study of gas dispersion near a cubical model building

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    Prepared for Site Safety Research Branch, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission.CER81-82WWL-RNM-JAP8.Includes bibliographical references

    Laboratory study of the impact of evaporative coolers on indoor PM concentrations

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    Abstract Evaporative cooling is used extensively in low humidity areas of the Southwest United States desert region and throughout other dry climate areas worldwide for residential thermal comfort. A literature review suggested the possibility of evaporative cooling increasing personal exposures to particulate matter along with increased incidences of respiratory illnesses. Indoor and outdoor particulate matter concentrations have been measured to determine the effects of evaporative cooling on ambient air in an evaporative cooler test chamber. The test chamber experiment was conducted to better evaluate the impact of evaporative cooling without interference by household activities such as cooking, cleaning, smoking, etc. Measurement of particulate matter was performed with tapered element oscillating microbalance (TEOM) instruments to provide a larger number of data points for comparison. Based on the experiments performed on two popular models of evaporative coolers, it was found that the evaporative cooler reduces indoor PM 10 by approximately 50%, and has a varying reduction effect of between 10 and 40% on PM 2:5 : These findings are consistent with the predicted outcomes suggested by particulate matter deposition models.

    Evaluation of sources and patterns of elemental composition of PM2. 5 at three low-income neighborhood schools and residences in Quito, Ecuador

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    Elemental characterization of fine particulate matter was undertaken at schools and residences in three low income neighborhoods in Quito, Ecuador. The three zones were located in the northern (Cotocollao), south central (El Camal), and south east (Los Chillos) neighborhoods and were classified as zones 1–3, respectively. Forty elements were quantified via ICP-MS analysis. Amongst the geogenic elements, the concentration of Si was the most abundant followed by S, Al, and Ca. Elements with predominantly anthropogenic sources such as Zn, V, and Ni were higher in zone 3 school followed by zone 2 and zone 1 schools. Enrichment factors were calculated to study the role of crustal sources in the elemental concentrations. Geogenic elements, except K, all had valuesNi, V, Zn, Pb, As, Cr had \u3e10. Principal Component Analysis suggested that Ni and V concentrations were strongly attributable to pet coke and heavy oil combustion. Strong associations between As and Pb could be attributed to traffic and other industrial emissions. Resuspended dust, soil erosion, vehicular emissions (tailpipe, brake and tire wear, and engine abrasion), pet coke, heavy oil combustion, and heavy industrial operations were major contributors to air pollution

    Assessment of Indoor and Outdoor PM Species at Schools and Residences in a High-Altitude Ecuadorian Urban Center

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    An air monitoring campaign to assess children’s environmental exposures in schools and residences, both indoors and outdoors, was conducted in 2010 in three low-income neighborhoods in Z1(north), Z2(central), and Z3(southeast) zones of Quito, Ecuador - a major urban center of 2.2 million inhabitants situated 2850 meters above sea level in a narrow mountainous basin. Z1 zone, located in northern Quito, historically experienced emissions from quarries and moderate traffic. Z2 zone was influenced by heavy traffic in contrast to Z3 zone which experienced low traffic densities. Weekly averages of PM samples were collected at schools (one in each zone) and residences (Z1=47, Z2=45, and Z3=41) every month, over a twelve-month period at the three zones. Indoor PM2.5 concentrations ranged from 10.6±4.9 μg/m3 (Z1 school) to 29.0±30.5 μg/m3 (Z1 residences) and outdoor PM2.5 concentrations varied from 10.9±3.2 μg/m3 (Z1 school) to 14.3±10.1 μg/m3 (Z2 residences), across the three zones. The lowest values for PM10–2.5 for indoor and outdoor microenvironments were recorded at Z2 school, 5.7±2.8 μg/m3 and 7.9±2.2 μg/m3 , respectively. Outdoor school PM concentrations exhibited stronger associations with corresponding indoor values making them robust proxies for indoor exposures in naturally ventilated Quito public schools. Correlation analysis between the school and residential PM size fractions and the various pollutant and meteorological parameters from central ambient monitoring (CAM) sites suggested varying degrees of temporal relationship. Strong positive correlation was observed for outdoor PM2.5 at Z2 school and its corresponding CAM site (r=0.77) suggesting common traffic related emissions. Spatial heterogeneity in PM2.5 concentrations between CAM network and sampled sites was assessed using Coefficient of Divergence (COD) analysis. COD values were lower when CAM sites were paired with outdoor measurements (\u3c 0.2) and higher when CAM and indoor values were compared (\u3e 0.2), suggesting that CAM network in Quito may not represent actual indoor exposures

    Air Pollution and Acute Respiratory Response in a Panel of Asthmatic Children along the U.S.–Mexico Border

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    Background: Concerns regarding the health impact of urban air pollution on asthmatic children are pronounced along the U.S.–Mexico border because of rapid population growth near busy border highways and roads. Objectives: We conducted the first binational study of the impacts of air pollution on asthmatic children in Ciudad Juarez, Mexico, and El Paso, Texas, USA, and compared different exposure metrics to assess acute respiratory response. Methods: We recruited 58 asthmatic children from two schools in Ciudad Juarez and two schools in El Paso. A marker of airway inflammation [exhaled nitric oxide (eNO)], respiratory symptom surveys, and pollutant measurements (indoor and outdoor 48-hr size-fractionated particulate matter, 48-hr black carbon, and 96-hr nitrogen dioxide) were collected at each school for 16 weeks. We examined associations between the pollutants and respiratory response using generalized linear mixed models. Results: We observed small but consistent associations between eNO and numerous pollutant metrics, with estimated increases in eNO ranging from 1% to 3% per interquartile range increase in pollutant concentrations. Effect estimates from models using school-based concentrations were generally stronger than corresponding estimates based on concentrations from ambient air monitors. Both traffic-related and non–traffic-related particles were typically more robust predictors of eNO than was nitrogen dioxide, for which associations were highly sensitive to model specification. Associations differed significantly across the four school-based cohorts, consistent with heterogeneity in pollutant concentrations and cohort characteristics. Models examining respiratory symptoms were consistent with the null. Conclusions: The results indicate adverse effects of air pollution on the subclinical respiratory health of asthmatic children in this region and provide preliminary support for the use of air pollution monitors close to schools to track exposure and potential health risk in this population

    Aryl hydrocarbon receptor-mediated activity of particulate organic matter from the Paso del Norte airshed along the U.S.-Mexico border.

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    In this study, we determined the biologic activity of dichloromethane-extracted particulate matter < 10 micro m in aerodynamic diameter (PM10) obtained from filters at three sites in the Paso del Norte airshed, which includes El Paso, Texas, USA; Juarez, Chihuahua, Mexico, and Sunland Park, New Mexico, USA. The extracts were rich in polycyclic aromatic hydrocarbons (PAHs) and had significant biologic activity, measured using two in vitro assay systems: ethoxyresorufin-(O-deethylase (EROD) induction and the aryl hydrocarbon-receptor luciferase reporter system. In most cases, both EROD (5.25 pmol/min/mg protein) and luciferase activities (994 relative light units/mg) were highest in extracts from the Advance site located in an industrial neighborhood in Juarez. These values represented 58% and 55%, respectively, of induction associated with 1 micro M ss-naphthoflavone exposures. In contrast, little activity was observed at the Northeast Clinic site in El Paso, the reference site. In most cases, luciferase and EROD activity from extracts collected from the Tillman Health Center site, situated in downtown El Paso, fell between those observed at the other two sites. Overall, a statistically significant correlation existed between PM10 and EROD and luciferase activities. Chemical analysis of extracts collected from the Advance site demonstrated that concentrations of most PAHs were higher than those reported in most other metropolitan areas in the United States. Calculations made with these data suggest a cancer risk of 5-12 cases per 100,000 people. This risk estimate, as well as comparisons with the work of other investigators, raises concern regarding the potential for adverse health effects to the residents of this airshed. Further work is needed to understand the sources, exposure, and effects of PM10 and particulate organic material in the Paso del Norte airshed

    Air Pollution and Acute Respiratory Response in a Panel of Asthmatic Children along the U.S.–Mexico Border

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    Background: Concerns regarding the health impact of urban air pollution on asthmatic children are pronounced along the U.S.–Mexico border because of rapid population growth near busy border highways and roads

    Personal Exposure to Air Pollution in the Vicinity of U.S.-Mexico Border Crossings

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    69A3551747128This study focused on evaluating pollutant exposures in border crossing regions. Specifically, the study focused on particulate matter (PM2.5) exposure data collected from a group of schoolteachers in the El Paso region in Texas. The region is a gateway for freight movement between the United States and Mexico. A pool of teachers working at a school close to the border crossing area carried a backpack equipped with an air quality monitoring device and a portable global positioning system tracking device. A spatiotemporal exposure assessment was conducted to assess exposure in different microenvironments visited, with findings showing higher mean concentrations at school than either during commuting or at home. Personal monitoring results were also found to be higher by an average of 81 percent than readings from a regulatory monitor and a monitor placed outside the school. These findings highlight a need to expand the coverage and capabilities of current air quality monitoring networks in the region and to improve the indoor air quality in schools using targeted abatement techniques
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