Shaibal Mukerjee - Academia.edu (original) (raw)

Papers by Shaibal Mukerjee

Research paper thumbnail of Application of a dual fine particle sequential sampler, a tapered element oscillating microbalance, and other air monitoring methods to assess transboundary influences of PM2.5

Field Anal Chem Technol, 1999

Transboundary influences of particulate matter less than or equal to 2.5 m in aerodynamic diamete... more Transboundary influences of particulate matter less than or equal to 2.5 m in aerodynamic diameter (PM 2.5 ) have been investigated in a U.S.-Mexican border region with the use of a dual fine particle sequential sampler (DFPSS) and a tapered element oscillating microbalance (TEOMா). Daily measurements of PM 2.5 were conducted with the DFPSS. Short-term variations in the concentration of PM 2.5 were measured and analyzed on site with the use of a tapered element oscillating microbalance (TEOMா) to assess episodic emissions that may have crossed the border. Fine particle carbon measurements, taken with a dichotomous sampler, and meteorological measurements were also performed. Ambient monitoring with these sampling methods was conducted for 1 year at three fixed sites very close to the border of the Lower Rio Grande Valley. Elemental tracer analyses and wind sector analyses were performed to assess transboundary influences. Ad hoc sampler comparisons were also presented. Presentation of advantages and limitations of sampling methods in this study can help establish a baseline for assessing future air quality conditions of a transboundary nature in the Valley.

Research paper thumbnail of Lower Rio Grande Valley transboundary air pollution project (TAPP). Project report 1996--1997

Research paper thumbnail of Application of a dual fine particle sequential sampler, a tapered element oscillating microbalance, and other air monitoring methods to assess transboundary influences of PM2.5

Field Analytical Chemistry & Technology, 1999

Transboundary influences of particulate matter less than or equal to 2.5 m in aerodynamic diamete... more Transboundary influences of particulate matter less than or equal to 2.5 m in aerodynamic diameter (PM 2.5 ) have been investigated in a U.S.-Mexican border region with the use of a dual fine particle sequential sampler (DFPSS) and a tapered element oscillating microbalance (TEOMா). Daily measurements of PM 2.5 were conducted with the DFPSS. Short-term variations in the concentration of PM 2.5 were measured and analyzed on site with the use of a tapered element oscillating microbalance (TEOMா) to assess episodic emissions that may have crossed the border. Fine particle carbon measurements, taken with a dichotomous sampler, and meteorological measurements were also performed. Ambient monitoring with these sampling methods was conducted for 1 year at three fixed sites very close to the border of the Lower Rio Grande Valley. Elemental tracer analyses and wind sector analyses were performed to assess transboundary influences. Ad hoc sampler comparisons were also presented. Presentation of advantages and limitations of sampling methods in this study can help establish a baseline for assessing future air quality conditions of a transboundary nature in the Valley.

Research paper thumbnail of 172 Methods for Semivolatile Organics in Air and Housedust Used in the Spring 1993 Lower Rio Grande Valley Environmental Scoping Study

Research paper thumbnail of Spatial analysis of volatile organic compounds in South Philadelphia using passive samplers

Journal of the Air & Waste Management Association, 2016

Select volatile organic compounds (VOCs) were measured in the vicinity of a petroleum refinery an... more Select volatile organic compounds (VOCs) were measured in the vicinity of a petroleum refinery and related operations in South Philadelphia, Pennsylvania, USA using passive air sampling and laboratory analysis methods. Two-week, time-integrated samplers were deployed at seventeen sites which were aggregated into five site groups of varying distances from the refinery. Benzene, toluene, ethylbenzene, and xylene isomers (BTEX) and styrene concentrations were higher near the refinery's fenceline than for groups at the refinery's south edge, mid-distance, and farther removed locations. The near fenceline group was significantly higher than the refinery's north edge group for benzene and toluene but not for ethylbenzene or xylene isomers; styrene was lower at the near fenceline group versus the north edge group. For BTEX and styrene, the magnitude of estimated differences generally increased when proceeding through groups ever farther away from the petroleum refining. Perchloroethylene results were not suggestive of an influence from refining. These results suggest that emissions from the refinery complex contribute to higher concentrations of BTEX species and styrene in the vicinity of the plant with this influence declining as distance from the petroleum refining increases. Passive sampling methodology for VOCs as discussed here is employed in recently-enacted U.S. Environmental Protection Agency Methods 325A/B for determination of benzene concentrations at refinery fenceline locations. Spatial gradients of VOC concentration near the refinery fenceline were discerned in an area containing traffic and other VOC-related sources. Though limited, these findings can be useful in application of the method at such facilities to ascertain source influence.

Research paper thumbnail of Volatile organic compounds at two oil and natural gas production well pads in Colorado and Texas using passive samplers

Journal of the Air & Waste Management Association (1995), Jan 15, 2016

A pilot study was conducted in application of the U.S. Environmental Protection Agency (EPA) Meth... more A pilot study was conducted in application of the U.S. Environmental Protection Agency (EPA) Methods 325A/B variant for monitoring volatile organic compounds (VOCs) near two oil and natural gas (ONG) production well pads in the Texas Barnett Shale formation and Colorado Denver-Julesburg Basin (DJB) along with a traffic-dominated site in downtown Denver. As indicated in the EPA Method, VOC concentrations were measured for 14-day sampling periods using passive-diffusive tube samplers with Carbopack X sorbent at fenceline perimeter and other locations. VOCs were significantly higher at the DJB well pad versus Barnett well pad and were likely due to higher production levels at the DJB well pad during the study. Benzene and toluene were significantly higher at the DJB well pad versus downtown Denver. Except for perchloroethylene, VOCs measured at passive sampler locations (PSs) along the perimeter of the Barnett well pad were significantly higher than PSs farther away. At the DJB well pa...

Research paper thumbnail of A concept of risk apportionment of air emission sources for risk reduction considerations

Http Dx Doi Org 10 1080 09593339209385193, Dec 17, 2008

ABSTRACT

Research paper thumbnail of Spatial analysis and land use regression of VOCs and NO2 from school-based urban air monitoring in Detroit/Dearborn, USA

Science of the Total Environment, Sep 1, 2009

Passive ambient air sampling for nitrogen dioxide (NO(2)) and volatile organic compounds (VOCs) w... more Passive ambient air sampling for nitrogen dioxide (NO(2)) and volatile organic compounds (VOCs) was conducted at 25 school and two compliance sites in Detroit and Dearborn, Michigan, USA during the summer of 2005. Geographic Information System (GIS) data were calculated at each of 116 schools. The 25 selected schools were monitored to assess and model intra-urban gradients of air pollutants to evaluate impact of traffic and urban emissions on pollutant levels. Schools were chosen to be statistically representative of urban land use variables such as distance to major roadways, traffic intensity around the schools, distance to nearest point sources, population density, and distance to nearest border crossing. Two approaches were used to investigate spatial variability. First, Kruskal-Wallis analyses and pairwise comparisons on data from the schools examined coarse spatial differences based on city section and distance from heavily trafficked roads. Secondly, spatial variation on a finer scale and as a response to multiple factors was evaluated through land use regression (LUR) models via multiple linear regression. For weeklong exposures, VOCs did not exhibit spatial variability by city section or distance from major roads; NO(2) was significantly elevated in a section dominated by traffic and industrial influence versus a residential section. Somewhat in contrast to coarse spatial analyses, LUR results revealed spatial gradients in NO(2) and selected VOCs across the area. The process used to select spatially representative sites for air sampling and the results of coarse and fine spatial variability of air pollutants provide insights that may guide future air quality studies in assessing intra-urban gradients.

Research paper thumbnail of Development and Evaluation of Land-Use Regression Models Using Coupled Regional and Local Scale Air Quality Models in New Haven, Connecticut

Air Pollution and Health, Mar 22, 2010

Research paper thumbnail of Near-road measurements for nitrogen dioxide and its association with traffic exposure zones

Atmospheric Pollution Research, 2015

Research paper thumbnail of Field Method Comparison between Passive Air Samplers and Continuous Monitors for VOCs and NO2 in El Paso, Texas

This study evaluates the performance of Model 3300 Ogawa Passive Nitrogen Dioxide (NO 2 ) Sampler... more This study evaluates the performance of Model 3300 Ogawa Passive Nitrogen Dioxide (NO 2 ) Samplers and 3M 3520 Organic Vapor Monitors (OVMs) by comparing integrated passive sampling concentrations to averaged hourly NO 2 and volatile organic compound (VOC) measurements at two sites in El Paso, TX. Sampling periods were three time intervals (3-day weekend, 4-day weekday, and 7-day weekly) for three consecutive weeks. OVM concentrations were corrected for ambient pressure to account for higher elevation. Precise results (Ͻ5% relative standard deviation, RSD) were found for NO 2 measurements from collocated Ogawa samplers. Reproducibility was lower from duplicate OVMs for BTEX (benzene, toluene, ethylbenzene, and xylene isomers) VOCs (Ն7% RSD for 2-day samples) with better precision for longer sampling periods. Comparison of Ogawa NO 2 samplers with chemiluminescence measurements averaged over the same time period suggested potential calibration problems with the chemiluminescence analyzer. For BTEX species, generally good agreement was obtained between OVMs and automated-gas chromatograph (auto-GC) measurements. The OVMs successfully tracked increasing levels of VOCs recorded by the auto-GCs. However,

Research paper thumbnail of Evaluation of land use regression models for nitrogen dioxide and benzene in Four US cities

TheScientificWorldJournal, 2012

Spatial analysis studies have included the application of land use regression models (LURs) for h... more Spatial analysis studies have included the application of land use regression models (LURs) for health and air quality assessments. Recent LUR studies have collected nitrogen dioxide (NO(2)) and volatile organic compounds (VOCs) using passive samplers at urban air monitoring networks in El Paso and Dallas, TX, Detroit, MI, and Cleveland, OH to assess spatial variability and source influences. LURs were successfully developed to estimate pollutant concentrations throughout the study areas. Comparisons of development and predictive capabilities of LURs from these four cities are presented to address this issue of uniform application of LURs across study areas. Traffic and other urban variables were important predictors in the LURs although city-specific influences (such as border crossings) were also important. In addition, transferability of variables or LURs from one city to another may be problematic due to intercity differences and data availability or comparability. Thus, develop...

Research paper thumbnail of Reduced Forced Vital Capacity In Childhood Associated With Exposures To Petroleum-Related Compounds At Birth Residence

C47. NEW DEVELOPMENTS IN AIR POLLUTION EPIDEMIOLOGY AND EXPOSURE ASSESSMENT, 2010

... S. Mukerjee , AH Williams , L. Smith LM Neas1 2 1 3 US Environmental Protection Agency, Chape... more ... S. Mukerjee , AH Williams , L. Smith LM Neas1 2 1 3 US Environmental Protection Agency, Chapel Hill, NC, United States of America, US Environmental Protection Agency, Research Triangle 1 2 Park, NC, United States of America, Alion Science and Technology, Inc ...

Research paper thumbnail of Seasonal effects in land use regression models for nitrogen dioxide, coarse particulate matter, and gaseous ammonia in Cleveland, Ohio

Atmospheric Pollution Research, 2012

Research paper thumbnail of Comparison of modeled traffic exposure zones using on-road air pollution measurements

Atmospheric Pollution Research, 2015

Research paper thumbnail of Mobile Source Air Pollution Is Associated With Several Cardiopulmonary Outcomes In A Large Cardiac Catheterization Cohort

B51. AIR POLLUTION AND TEMPERATURE: CARDIOVASCULAR EFFECTS, 2012

ABSTRACT CATHGEN is a large (N = 9334) sequentially-sampled cohort of patients presenting to the ... more ABSTRACT CATHGEN is a large (N = 9334) sequentially-sampled cohort of patients presenting to the Duke University Cardiac Catheterization Laboratory from 2001-2011. With residential location for 8079 (86.5%) of cohort individuals, we have created a powerful resource to understand the relation between environmental exposures and cardiovascular disease (CVD). In this study we used 843 CATHGEN participants in the tri-county area of Durham, Wake, and Orange counties, NC (DWO) to identify associations between mobile source air pollution and 61 specific metabolites from a targeted metabolic profiling panel. We used distance to the nearest primary or secondary roadway (DTR) as a proxy for mobile source air pollution and adjusted each association for race, sex, smoking status, and socioeconomic status. Metabolite concentrations were log-transformed before analysis. In DWO we saw multiple associations between DTR and both short and long-chain acylcarnitines. DTR was associated with an increase in the short-chain acylcarnitines C5:1 (β = 0.087 P = 0.033) and C5-OH/C3-DC (β = 0.777, P = 0.016). Plasma concentrations of acylcarnitine C18:2 were lower among study participants living closer to roadways (β = -0.056, P = 0.008). We saw modest associations between DTR and acylcarnitines C14-OH/C12-DC (β = 0.250, P = 0.063), C18:1 (β = -0.036, P = 0.051), and C18-OH/C16-DC (β = 0.645, P = 0.056). C18:2, C14-OH/C12-DC, C18:1, and C18-OH/C16-DC are all related to β-oxidation. We saw negative associations with distance to roadways for C18:2 and C18:1 acylcarnitines and positive associations with DTR for C14-OH/C12-DC and C18-OH/C16-DC. β-oxidation is an important source of energy in the mitochondria and altered concentrations of β-oxidation related acylcarnitines are often markers of mitochondrial dysfunction. Further studies are needed to explore the relationship between β-oxidation related acylcarnitines and mobile source air pollution. Our two remaining associations were C5:1 and C5-OH/C3-DC. C5:1 is related to branched chain amino acid metabolism. In published analyses branched chain amino acids were associated with coronary artery disease (CAD) prevalence, with higher plasma concentrations of branched chain amino acids seen in CAD cases as compared to controls. In conclusion we examined a targeted metabolic panel of 61 metabolites for association with distance to roadways, a proxy for mobile source air pollution. We saw associations between specific long-chain β-oxidation related acylcarnitines as well as with two short-chain acylcarnitines, one related to branched chain amino acid metabolism. Using the clinical and molecular data available in CATHGEN we will explore these associations further to determine if specific genes and pathways related to these acylcarnitines are also associated with mobile source air pollution. Circulation. 2013; 127: AP182

Research paper thumbnail of Gaseous oxidized mercury dry deposition measurements in the Four Corners Area and Eastern Oklahoma, U.S.A

Atmospheric Pollution Research, 2013

Gaseous oxidized mercury (GOM) dry deposition measurements using surrogate surface passive sample... more Gaseous oxidized mercury (GOM) dry deposition measurements using surrogate surface passive samplers were collected in the Four Corners area and eastern Oklahoma from August, 2009-August, 2011. Using data from a six site area network, a characterization of the magnitude and spatial extent of ambient mercury pollution in the arid Four Corners area was accomplished, which included the observation of a strong regional signature in the GOM dry deposition data set. GOM dry deposition rate estimates ranged from 0.4-1.0 ng/m 2 h at the six Four Corners area monitoring sites, while the GOM dry deposition rate estimate at the eastern Oklahoma monitoring site was lower at 0.2 ng/m 2 h. The highest GOM dry deposition estimates were recorded during the spring and summer while the lowest GOM dry deposition estimates were recorded during the fall and winter. During the second year of this study the highest annual GOM dry deposition estimate so far measured in the United States (U.S.) with smooth-edge surrogate surface passive samplers, 10 889 ng/m 2 , was recorded at the Mesa Verde National Park site, a site at which the twoyear cumulative GOM dry deposition estimate exceeded the mercury wet deposition estimate. GOM dry deposition estimates during the second year of the study were statistically significantly higher than the first year of the study at six of the seven sites. The data from this study provide a two-year baseline of GOM dry deposition data in the Four Corners area and eastern Oklahoma immediately before the current implementation of new U.S. power plant and boiler mercury control regulations which will significantly reduce mercury emissions from those two sectors of local and regional anthropogenic mercury emission sources.

Research paper thumbnail of Evaluation of land use regression models for NO2 in El Paso, Texas, USA

The Science of the total environment, Jan 15, 2012

Developing suitable exposure estimates for air pollution health studies is problematic due to spa... more Developing suitable exposure estimates for air pollution health studies is problematic due to spatial and temporal variation in concentrations and often limited monitoring data. Though land use regression models (LURs) are often used for this purpose, their applicability to later periods of time, larger geographic areas, and seasonal variation is largely untested. We evaluate a series of mixed model LURs to describe the spatial-temporal gradients of NO(2) across El Paso County, Texas based on measurements collected during cool and warm seasons in 2006-2007 (2006-7). We also evaluated performance of a general additive model (GAM) developed for central El Paso in 1999 to assess spatial gradients across the County in 2006-7. Five LURs were developed iteratively from the study data and their predictions were averaged to provide robust nitrogen dioxide (NO(2)) concentration gradients across the county. Despite differences in sampling time frame, model covariates and model estimation meth...

Research paper thumbnail of Spatial analysis and land use regression of VOCs and NO2 from school-based urban air monitoring in Detroit/Dearborn, USA

Science of The Total Environment, 2009

Passive ambient air sampling for nitrogen dioxide (NO(2)) and volatile organic compounds (VOCs) w... more Passive ambient air sampling for nitrogen dioxide (NO(2)) and volatile organic compounds (VOCs) was conducted at 25 school and two compliance sites in Detroit and Dearborn, Michigan, USA during the summer of 2005. Geographic Information System (GIS) data were calculated at each of 116 schools. The 25 selected schools were monitored to assess and model intra-urban gradients of air pollutants to evaluate impact of traffic and urban emissions on pollutant levels. Schools were chosen to be statistically representative of urban land use variables such as distance to major roadways, traffic intensity around the schools, distance to nearest point sources, population density, and distance to nearest border crossing. Two approaches were used to investigate spatial variability. First, Kruskal-Wallis analyses and pairwise comparisons on data from the schools examined coarse spatial differences based on city section and distance from heavily trafficked roads. Secondly, spatial variation on a finer scale and as a response to multiple factors was evaluated through land use regression (LUR) models via multiple linear regression. For weeklong exposures, VOCs did not exhibit spatial variability by city section or distance from major roads; NO(2) was significantly elevated in a section dominated by traffic and industrial influence versus a residential section. Somewhat in contrast to coarse spatial analyses, LUR results revealed spatial gradients in NO(2) and selected VOCs across the area. The process used to select spatially representative sites for air sampling and the results of coarse and fine spatial variability of air pollutants provide insights that may guide future air quality studies in assessing intra-urban gradients.

Research paper thumbnail of Techniques to assess cross-border air pollution and application to a US-Mexico border region

Science of The Total Environment, 2001

A year-long assessment of cross-border air pollution was conducted in the eastmost section of the... more A year-long assessment of cross-border air pollution was conducted in the eastmost section of the US-Mexico border region, known as the Lower Rio Grande Valley, in South Texas. Measurements were conducted on the US Ž . Ž . side and included fine particle mass PM and elemental composition, volatile organic compounds VOCs and 2.5 meteorology. Wind sector analyses of chemical tracers and diagnostic ratios, in addition to principal component Ž . analysis PCA , were initially applied to assess cross-border and overall air shed influences. Linear-angular w Ž .

Research paper thumbnail of Application of a dual fine particle sequential sampler, a tapered element oscillating microbalance, and other air monitoring methods to assess transboundary influences of PM2.5

Field Anal Chem Technol, 1999

Transboundary influences of particulate matter less than or equal to 2.5 m in aerodynamic diamete... more Transboundary influences of particulate matter less than or equal to 2.5 m in aerodynamic diameter (PM 2.5 ) have been investigated in a U.S.-Mexican border region with the use of a dual fine particle sequential sampler (DFPSS) and a tapered element oscillating microbalance (TEOMா). Daily measurements of PM 2.5 were conducted with the DFPSS. Short-term variations in the concentration of PM 2.5 were measured and analyzed on site with the use of a tapered element oscillating microbalance (TEOMா) to assess episodic emissions that may have crossed the border. Fine particle carbon measurements, taken with a dichotomous sampler, and meteorological measurements were also performed. Ambient monitoring with these sampling methods was conducted for 1 year at three fixed sites very close to the border of the Lower Rio Grande Valley. Elemental tracer analyses and wind sector analyses were performed to assess transboundary influences. Ad hoc sampler comparisons were also presented. Presentation of advantages and limitations of sampling methods in this study can help establish a baseline for assessing future air quality conditions of a transboundary nature in the Valley.

Research paper thumbnail of Lower Rio Grande Valley transboundary air pollution project (TAPP). Project report 1996--1997

Research paper thumbnail of Application of a dual fine particle sequential sampler, a tapered element oscillating microbalance, and other air monitoring methods to assess transboundary influences of PM2.5

Field Analytical Chemistry & Technology, 1999

Transboundary influences of particulate matter less than or equal to 2.5 m in aerodynamic diamete... more Transboundary influences of particulate matter less than or equal to 2.5 m in aerodynamic diameter (PM 2.5 ) have been investigated in a U.S.-Mexican border region with the use of a dual fine particle sequential sampler (DFPSS) and a tapered element oscillating microbalance (TEOMா). Daily measurements of PM 2.5 were conducted with the DFPSS. Short-term variations in the concentration of PM 2.5 were measured and analyzed on site with the use of a tapered element oscillating microbalance (TEOMா) to assess episodic emissions that may have crossed the border. Fine particle carbon measurements, taken with a dichotomous sampler, and meteorological measurements were also performed. Ambient monitoring with these sampling methods was conducted for 1 year at three fixed sites very close to the border of the Lower Rio Grande Valley. Elemental tracer analyses and wind sector analyses were performed to assess transboundary influences. Ad hoc sampler comparisons were also presented. Presentation of advantages and limitations of sampling methods in this study can help establish a baseline for assessing future air quality conditions of a transboundary nature in the Valley.

Research paper thumbnail of 172 Methods for Semivolatile Organics in Air and Housedust Used in the Spring 1993 Lower Rio Grande Valley Environmental Scoping Study

Research paper thumbnail of Spatial analysis of volatile organic compounds in South Philadelphia using passive samplers

Journal of the Air & Waste Management Association, 2016

Select volatile organic compounds (VOCs) were measured in the vicinity of a petroleum refinery an... more Select volatile organic compounds (VOCs) were measured in the vicinity of a petroleum refinery and related operations in South Philadelphia, Pennsylvania, USA using passive air sampling and laboratory analysis methods. Two-week, time-integrated samplers were deployed at seventeen sites which were aggregated into five site groups of varying distances from the refinery. Benzene, toluene, ethylbenzene, and xylene isomers (BTEX) and styrene concentrations were higher near the refinery's fenceline than for groups at the refinery's south edge, mid-distance, and farther removed locations. The near fenceline group was significantly higher than the refinery's north edge group for benzene and toluene but not for ethylbenzene or xylene isomers; styrene was lower at the near fenceline group versus the north edge group. For BTEX and styrene, the magnitude of estimated differences generally increased when proceeding through groups ever farther away from the petroleum refining. Perchloroethylene results were not suggestive of an influence from refining. These results suggest that emissions from the refinery complex contribute to higher concentrations of BTEX species and styrene in the vicinity of the plant with this influence declining as distance from the petroleum refining increases. Passive sampling methodology for VOCs as discussed here is employed in recently-enacted U.S. Environmental Protection Agency Methods 325A/B for determination of benzene concentrations at refinery fenceline locations. Spatial gradients of VOC concentration near the refinery fenceline were discerned in an area containing traffic and other VOC-related sources. Though limited, these findings can be useful in application of the method at such facilities to ascertain source influence.

Research paper thumbnail of Volatile organic compounds at two oil and natural gas production well pads in Colorado and Texas using passive samplers

Journal of the Air & Waste Management Association (1995), Jan 15, 2016

A pilot study was conducted in application of the U.S. Environmental Protection Agency (EPA) Meth... more A pilot study was conducted in application of the U.S. Environmental Protection Agency (EPA) Methods 325A/B variant for monitoring volatile organic compounds (VOCs) near two oil and natural gas (ONG) production well pads in the Texas Barnett Shale formation and Colorado Denver-Julesburg Basin (DJB) along with a traffic-dominated site in downtown Denver. As indicated in the EPA Method, VOC concentrations were measured for 14-day sampling periods using passive-diffusive tube samplers with Carbopack X sorbent at fenceline perimeter and other locations. VOCs were significantly higher at the DJB well pad versus Barnett well pad and were likely due to higher production levels at the DJB well pad during the study. Benzene and toluene were significantly higher at the DJB well pad versus downtown Denver. Except for perchloroethylene, VOCs measured at passive sampler locations (PSs) along the perimeter of the Barnett well pad were significantly higher than PSs farther away. At the DJB well pa...

Research paper thumbnail of A concept of risk apportionment of air emission sources for risk reduction considerations

Http Dx Doi Org 10 1080 09593339209385193, Dec 17, 2008

ABSTRACT

Research paper thumbnail of Spatial analysis and land use regression of VOCs and NO2 from school-based urban air monitoring in Detroit/Dearborn, USA

Science of the Total Environment, Sep 1, 2009

Passive ambient air sampling for nitrogen dioxide (NO(2)) and volatile organic compounds (VOCs) w... more Passive ambient air sampling for nitrogen dioxide (NO(2)) and volatile organic compounds (VOCs) was conducted at 25 school and two compliance sites in Detroit and Dearborn, Michigan, USA during the summer of 2005. Geographic Information System (GIS) data were calculated at each of 116 schools. The 25 selected schools were monitored to assess and model intra-urban gradients of air pollutants to evaluate impact of traffic and urban emissions on pollutant levels. Schools were chosen to be statistically representative of urban land use variables such as distance to major roadways, traffic intensity around the schools, distance to nearest point sources, population density, and distance to nearest border crossing. Two approaches were used to investigate spatial variability. First, Kruskal-Wallis analyses and pairwise comparisons on data from the schools examined coarse spatial differences based on city section and distance from heavily trafficked roads. Secondly, spatial variation on a finer scale and as a response to multiple factors was evaluated through land use regression (LUR) models via multiple linear regression. For weeklong exposures, VOCs did not exhibit spatial variability by city section or distance from major roads; NO(2) was significantly elevated in a section dominated by traffic and industrial influence versus a residential section. Somewhat in contrast to coarse spatial analyses, LUR results revealed spatial gradients in NO(2) and selected VOCs across the area. The process used to select spatially representative sites for air sampling and the results of coarse and fine spatial variability of air pollutants provide insights that may guide future air quality studies in assessing intra-urban gradients.

Research paper thumbnail of Development and Evaluation of Land-Use Regression Models Using Coupled Regional and Local Scale Air Quality Models in New Haven, Connecticut

Air Pollution and Health, Mar 22, 2010

Research paper thumbnail of Near-road measurements for nitrogen dioxide and its association with traffic exposure zones

Atmospheric Pollution Research, 2015

Research paper thumbnail of Field Method Comparison between Passive Air Samplers and Continuous Monitors for VOCs and NO2 in El Paso, Texas

This study evaluates the performance of Model 3300 Ogawa Passive Nitrogen Dioxide (NO 2 ) Sampler... more This study evaluates the performance of Model 3300 Ogawa Passive Nitrogen Dioxide (NO 2 ) Samplers and 3M 3520 Organic Vapor Monitors (OVMs) by comparing integrated passive sampling concentrations to averaged hourly NO 2 and volatile organic compound (VOC) measurements at two sites in El Paso, TX. Sampling periods were three time intervals (3-day weekend, 4-day weekday, and 7-day weekly) for three consecutive weeks. OVM concentrations were corrected for ambient pressure to account for higher elevation. Precise results (Ͻ5% relative standard deviation, RSD) were found for NO 2 measurements from collocated Ogawa samplers. Reproducibility was lower from duplicate OVMs for BTEX (benzene, toluene, ethylbenzene, and xylene isomers) VOCs (Ն7% RSD for 2-day samples) with better precision for longer sampling periods. Comparison of Ogawa NO 2 samplers with chemiluminescence measurements averaged over the same time period suggested potential calibration problems with the chemiluminescence analyzer. For BTEX species, generally good agreement was obtained between OVMs and automated-gas chromatograph (auto-GC) measurements. The OVMs successfully tracked increasing levels of VOCs recorded by the auto-GCs. However,

Research paper thumbnail of Evaluation of land use regression models for nitrogen dioxide and benzene in Four US cities

TheScientificWorldJournal, 2012

Spatial analysis studies have included the application of land use regression models (LURs) for h... more Spatial analysis studies have included the application of land use regression models (LURs) for health and air quality assessments. Recent LUR studies have collected nitrogen dioxide (NO(2)) and volatile organic compounds (VOCs) using passive samplers at urban air monitoring networks in El Paso and Dallas, TX, Detroit, MI, and Cleveland, OH to assess spatial variability and source influences. LURs were successfully developed to estimate pollutant concentrations throughout the study areas. Comparisons of development and predictive capabilities of LURs from these four cities are presented to address this issue of uniform application of LURs across study areas. Traffic and other urban variables were important predictors in the LURs although city-specific influences (such as border crossings) were also important. In addition, transferability of variables or LURs from one city to another may be problematic due to intercity differences and data availability or comparability. Thus, develop...

Research paper thumbnail of Reduced Forced Vital Capacity In Childhood Associated With Exposures To Petroleum-Related Compounds At Birth Residence

C47. NEW DEVELOPMENTS IN AIR POLLUTION EPIDEMIOLOGY AND EXPOSURE ASSESSMENT, 2010

... S. Mukerjee , AH Williams , L. Smith LM Neas1 2 1 3 US Environmental Protection Agency, Chape... more ... S. Mukerjee , AH Williams , L. Smith LM Neas1 2 1 3 US Environmental Protection Agency, Chapel Hill, NC, United States of America, US Environmental Protection Agency, Research Triangle 1 2 Park, NC, United States of America, Alion Science and Technology, Inc ...

Research paper thumbnail of Seasonal effects in land use regression models for nitrogen dioxide, coarse particulate matter, and gaseous ammonia in Cleveland, Ohio

Atmospheric Pollution Research, 2012

Research paper thumbnail of Comparison of modeled traffic exposure zones using on-road air pollution measurements

Atmospheric Pollution Research, 2015

Research paper thumbnail of Mobile Source Air Pollution Is Associated With Several Cardiopulmonary Outcomes In A Large Cardiac Catheterization Cohort

B51. AIR POLLUTION AND TEMPERATURE: CARDIOVASCULAR EFFECTS, 2012

ABSTRACT CATHGEN is a large (N = 9334) sequentially-sampled cohort of patients presenting to the ... more ABSTRACT CATHGEN is a large (N = 9334) sequentially-sampled cohort of patients presenting to the Duke University Cardiac Catheterization Laboratory from 2001-2011. With residential location for 8079 (86.5%) of cohort individuals, we have created a powerful resource to understand the relation between environmental exposures and cardiovascular disease (CVD). In this study we used 843 CATHGEN participants in the tri-county area of Durham, Wake, and Orange counties, NC (DWO) to identify associations between mobile source air pollution and 61 specific metabolites from a targeted metabolic profiling panel. We used distance to the nearest primary or secondary roadway (DTR) as a proxy for mobile source air pollution and adjusted each association for race, sex, smoking status, and socioeconomic status. Metabolite concentrations were log-transformed before analysis. In DWO we saw multiple associations between DTR and both short and long-chain acylcarnitines. DTR was associated with an increase in the short-chain acylcarnitines C5:1 (β = 0.087 P = 0.033) and C5-OH/C3-DC (β = 0.777, P = 0.016). Plasma concentrations of acylcarnitine C18:2 were lower among study participants living closer to roadways (β = -0.056, P = 0.008). We saw modest associations between DTR and acylcarnitines C14-OH/C12-DC (β = 0.250, P = 0.063), C18:1 (β = -0.036, P = 0.051), and C18-OH/C16-DC (β = 0.645, P = 0.056). C18:2, C14-OH/C12-DC, C18:1, and C18-OH/C16-DC are all related to β-oxidation. We saw negative associations with distance to roadways for C18:2 and C18:1 acylcarnitines and positive associations with DTR for C14-OH/C12-DC and C18-OH/C16-DC. β-oxidation is an important source of energy in the mitochondria and altered concentrations of β-oxidation related acylcarnitines are often markers of mitochondrial dysfunction. Further studies are needed to explore the relationship between β-oxidation related acylcarnitines and mobile source air pollution. Our two remaining associations were C5:1 and C5-OH/C3-DC. C5:1 is related to branched chain amino acid metabolism. In published analyses branched chain amino acids were associated with coronary artery disease (CAD) prevalence, with higher plasma concentrations of branched chain amino acids seen in CAD cases as compared to controls. In conclusion we examined a targeted metabolic panel of 61 metabolites for association with distance to roadways, a proxy for mobile source air pollution. We saw associations between specific long-chain β-oxidation related acylcarnitines as well as with two short-chain acylcarnitines, one related to branched chain amino acid metabolism. Using the clinical and molecular data available in CATHGEN we will explore these associations further to determine if specific genes and pathways related to these acylcarnitines are also associated with mobile source air pollution. Circulation. 2013; 127: AP182

Research paper thumbnail of Gaseous oxidized mercury dry deposition measurements in the Four Corners Area and Eastern Oklahoma, U.S.A

Atmospheric Pollution Research, 2013

Gaseous oxidized mercury (GOM) dry deposition measurements using surrogate surface passive sample... more Gaseous oxidized mercury (GOM) dry deposition measurements using surrogate surface passive samplers were collected in the Four Corners area and eastern Oklahoma from August, 2009-August, 2011. Using data from a six site area network, a characterization of the magnitude and spatial extent of ambient mercury pollution in the arid Four Corners area was accomplished, which included the observation of a strong regional signature in the GOM dry deposition data set. GOM dry deposition rate estimates ranged from 0.4-1.0 ng/m 2 h at the six Four Corners area monitoring sites, while the GOM dry deposition rate estimate at the eastern Oklahoma monitoring site was lower at 0.2 ng/m 2 h. The highest GOM dry deposition estimates were recorded during the spring and summer while the lowest GOM dry deposition estimates were recorded during the fall and winter. During the second year of this study the highest annual GOM dry deposition estimate so far measured in the United States (U.S.) with smooth-edge surrogate surface passive samplers, 10 889 ng/m 2 , was recorded at the Mesa Verde National Park site, a site at which the twoyear cumulative GOM dry deposition estimate exceeded the mercury wet deposition estimate. GOM dry deposition estimates during the second year of the study were statistically significantly higher than the first year of the study at six of the seven sites. The data from this study provide a two-year baseline of GOM dry deposition data in the Four Corners area and eastern Oklahoma immediately before the current implementation of new U.S. power plant and boiler mercury control regulations which will significantly reduce mercury emissions from those two sectors of local and regional anthropogenic mercury emission sources.

Research paper thumbnail of Evaluation of land use regression models for NO2 in El Paso, Texas, USA

The Science of the total environment, Jan 15, 2012

Developing suitable exposure estimates for air pollution health studies is problematic due to spa... more Developing suitable exposure estimates for air pollution health studies is problematic due to spatial and temporal variation in concentrations and often limited monitoring data. Though land use regression models (LURs) are often used for this purpose, their applicability to later periods of time, larger geographic areas, and seasonal variation is largely untested. We evaluate a series of mixed model LURs to describe the spatial-temporal gradients of NO(2) across El Paso County, Texas based on measurements collected during cool and warm seasons in 2006-2007 (2006-7). We also evaluated performance of a general additive model (GAM) developed for central El Paso in 1999 to assess spatial gradients across the County in 2006-7. Five LURs were developed iteratively from the study data and their predictions were averaged to provide robust nitrogen dioxide (NO(2)) concentration gradients across the county. Despite differences in sampling time frame, model covariates and model estimation meth...

Research paper thumbnail of Spatial analysis and land use regression of VOCs and NO2 from school-based urban air monitoring in Detroit/Dearborn, USA

Science of The Total Environment, 2009

Passive ambient air sampling for nitrogen dioxide (NO(2)) and volatile organic compounds (VOCs) w... more Passive ambient air sampling for nitrogen dioxide (NO(2)) and volatile organic compounds (VOCs) was conducted at 25 school and two compliance sites in Detroit and Dearborn, Michigan, USA during the summer of 2005. Geographic Information System (GIS) data were calculated at each of 116 schools. The 25 selected schools were monitored to assess and model intra-urban gradients of air pollutants to evaluate impact of traffic and urban emissions on pollutant levels. Schools were chosen to be statistically representative of urban land use variables such as distance to major roadways, traffic intensity around the schools, distance to nearest point sources, population density, and distance to nearest border crossing. Two approaches were used to investigate spatial variability. First, Kruskal-Wallis analyses and pairwise comparisons on data from the schools examined coarse spatial differences based on city section and distance from heavily trafficked roads. Secondly, spatial variation on a finer scale and as a response to multiple factors was evaluated through land use regression (LUR) models via multiple linear regression. For weeklong exposures, VOCs did not exhibit spatial variability by city section or distance from major roads; NO(2) was significantly elevated in a section dominated by traffic and industrial influence versus a residential section. Somewhat in contrast to coarse spatial analyses, LUR results revealed spatial gradients in NO(2) and selected VOCs across the area. The process used to select spatially representative sites for air sampling and the results of coarse and fine spatial variability of air pollutants provide insights that may guide future air quality studies in assessing intra-urban gradients.

Research paper thumbnail of Techniques to assess cross-border air pollution and application to a US-Mexico border region

Science of The Total Environment, 2001

A year-long assessment of cross-border air pollution was conducted in the eastmost section of the... more A year-long assessment of cross-border air pollution was conducted in the eastmost section of the US-Mexico border region, known as the Lower Rio Grande Valley, in South Texas. Measurements were conducted on the US Ž . Ž . side and included fine particle mass PM and elemental composition, volatile organic compounds VOCs and 2.5 meteorology. Wind sector analyses of chemical tracers and diagnostic ratios, in addition to principal component Ž . analysis PCA , were initially applied to assess cross-border and overall air shed influences. Linear-angular w Ž .