The NARSTO_EPA_SS_HOUSTON_NO3_SO4_C_DATA files contain continuous measurements of PM2.5 nitrate, PM2.5 sulfate, and PM2.5 carbon collected during August 12, 2000 through November 5, 2001 at the Aldine, Deer Park, and LaPorte Houston Supersite monitoring locations. Nitrate measurements were collected using the R&P 8400N Method. Sulfate and carbon measurements were collected using the Prototype ADI Particulate Sulfate and Carbon Monitor Method.The Houston Supersite is one of several Supersites that was established in urban areas within the United States by the U.S. Environmental Protection Agency (EPA) to better understand the measurement, sources, and health effects of suspended particulate matter (PM). The overall goals were to characterize the composition and identify the sources of particulate matter in Southeastern Texas, to develop and test new methods for characterizing fine particulate matter, and to collect data on the physical and chemical characterization of fine particulate matter that can be used to support exposure and health effects studies.NARSTO (formerly North American Research Strategy for Tropospheric Ozone) is a public/private partnership, whose membership spans government, the utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission is to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are available.

The NARSTO_EPA_SS_LOS_ANGELES_PM25_NITRATE data were collected between July 2001 and January 2002. At Claremont and Rubidoux (Los Angeles County, California), Cascaded Integrated Collection and Vaporization System for Particulate Nitrate (ICVS for Nitrate) was used in a mobile trailer to collect PM2.5 particulate nitrate data during July 11, 2001 to January 11, 2002. The ICVS for Nitrate measured PM2.5 particulate nitrate data that cover sizes from 0.1-2.5um in every 10 minutes.The overall objective of the Los Angeles Supersite in Southern California Particle Center and Supersite (SCPCS) is to conduct monitoring and research that contributes to a better understanding of the measurement, sources, size distribution, chemical composition and physical state, spatial and temporal variability, and linkages to health effects of airborne particulate matter in the Los Angeles Basin.The U.S. EPA Particulate Matter (PM) Supersites Program was an ambient air monitoring research program designed to provide information of value to the atmospheric sciences, and human health and exposure research communities. Eight geographically diverse projects were chosen to specifically address these EPA research priorities: (1) to characterize PM, its constituents, precursors, co-pollutants, atmospheric transport, and its source categories that affect the PM in any region; (2) to address the research questions and scientific uncertainties about PM source-receptor and exposure-health effects relationships; and (3) to compare and evaluate different methods of characterizing PM including testing new and emerging measurement methods.NARSTO (formerly North American Research Strategy for Tropospheric Ozone) is a public/private partnership, whose membership spans government, the utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission is to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are available.

The NARSTO_EPA_SS_LOS_ANGELES_PM25_NITRATE data were collected between July 2001 and January 2002. At Claremont and Rubidoux (Los Angeles County, California), Cascaded Integrated Collection and Vaporization System for Particulate Nitrate (ICVS for Nitrate) was used in a mobile trailer to collect PM2.5 particulate nitrate data during July 11, 2001 to January 11, 2002. The ICVS for Nitrate measured PM2.5 particulate nitrate data that cover sizes from 0.1-2.5um in every 10 minutes.The overall objective of the Los Angeles Supersite in Southern California Particle Center and Supersite (SCPCS) is to conduct monitoring and research that contributes to a better understanding of the measurement, sources, size distribution, chemical composition and physical state, spatial and temporal variability, and linkages to health effects of airborne particulate matter in the Los Angeles Basin.The U.S. EPA Particulate Matter (PM) Supersites Program was an ambient air monitoring research program designed to provide information of value to the atmospheric sciences, and human health and exposure research communities. Eight geographically diverse projects were chosen to specifically address these EPA research priorities: (1) to characterize PM, its constituents, precursors, co-pollutants, atmospheric transport, and its source categories that affect the PM in any region; (2) to address the research questions and scientific uncertainties about PM source-receptor and exposure-health effects relationships; and (3) to compare and evaluate different methods of characterizing PM including testing new and emerging measurement methods.NARSTO (formerly North American Research Strategy for Tropospheric Ozone) is a public/private partnership, whose membership spans government, the utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission is to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are available.

The NARSTO_EPA_SS_HOUSTON_TEXAQS2000_PM_FTIR measurement data consist of absolute absorbance areas for organonitrates, sulfate, aliphatic carbon and carbonyl compounds for size segregated particulate matter collected using a Herring Low Pressure Impactor (LPI). These data were collected during August and September 2000 at the Houston PM Supersite locations (LaPorte, HRM3, and Aldine) during the Texas Air Quality Study 2000 (TexAQS).The Houston Supersite is one of several Supersites that was established in urban areas within the United States by the U.S. Environmental Protection Agency (EPA) to better understand the measurement, sources, and health effects of suspended particulate matter (PM). The overall goals were to characterize the composition and identify the sources of particulate matter in Southeastern Texas, to develop and test new methods for characterizing fine particulate matter, and to collect data on the physical and chemical characterization of fine particulate matter that can be used to support exposure and health effects studies.NARSTO (formerly North American Research Strategy for Tropospheric Ozone) is a public/private partnership, whose membership spans government, the utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission is to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are available.

The NARSTO_EPA_SS_FRESNO_PM25_NO3_SO4 is the North American Research Strategy for Tropospheric Ozone (NARSTO) Environmental Protection Agency (EPA) Supersite (SS) Fresno, Particulate Matter (PM) 2.5 Particulate Nitrate and Sulfate Data. This data set contains measurements taken from two nitrate monitors and one sulfate monitor operated at the Fresno Supersite. The sample collection time for all instruments was 8 minutes. The sample analysis time was 2 minutes. Data were output once every 10 minutes. The Rupprecht and Patashnick (R&P) Ambient Particulate Nitrate Monitor measured the amount of particulate nitrate in an air sample at a nearly continuous rate. The Rupprecht and Patashnick (R&P) Ambient Particulate Sulfate Monitor measured the amount of particulate sulfate in an air sample at a nearly continuous rate. The ambient aerosol was collected by impaction on a small metallic strip. At the end of collection, the strip was heated to vaporize and decompose the particulate matter into oxides which were then measured. The Fresno Supersite is one of several Supersites established in urban areas within the United States by the EPA to better understand the measurement, sources, and health effects of suspended particulate matter (PM). The site is located at 3425 First Street, approximately 1 km north of the downtown commercial district. First Street was a four-lane artery with moderate traffic levels. Commercial establishments, office buildings, churches, and schools were located north and south of the monitor. Medium-density single-family homes and some apartments were located in the blocks to the east and west of First Street. The Fresno Supersite began operation in May of 1999.The EPA PM Supersites Program was an ambient air monitoring research program designed to provide information of value to the atmospheric sciences, and human health and exposure research communities. Eight geographically diverse projects were chosen to specifically address the following EPA research priorities: (1) to characterize PM, its constituents, precursors, co-pollutants, atmospheric transport, and its source categories that affect the PM in any region; (2) to address the research questions and scientific uncertainties about PM source-receptor and exposure-health effects relationships; and (3) to compare and evaluate different methods of characterizing PM including testing new and emerging measurement methods. NARSTO, which has since disbanded, was a public/private partnership, whose membership spanned across government, utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission was to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are still available.

The NARSTO_SOS_SC_UPSTATE_PM25_COMPOSITION data were collected during July 2001 and January of 2002 to elucidate the seasonal variability of the aerosols. Samples were collected at a rural location in South Carolina, beginning and ending at midnight in order to associate each sampling event with a calendar day. In all, 40 samples per month were collected (including blanks).The purpose of the study was to determine experimentally the concentration and chemical composition of fine particulate matter (PM2.5, particles with a diameter less than 2.5 um) in South Carolina. The collection of PM2.5 samples on Teflon filters was carried out using a cyclone-based system. Ion chromatography analysis for anions and cations was performed, as well as x-ray fluorescence (XRF) analysis for crustal metals. PM2.5 samples on quartz filters were also collected in order to determine the organic and elemental carbon (EC/OC) particle concentration.The average concentration for PM2.5 during July of 2001 was 20.85 mg/m3. The major components of the aerosol were organic compounds (38.5%) and sulfates (34.7%). During January of 2002, the average concentration for PM2.5 was 9.4 mg/m3. Again, the major components of the aerosol were organic compounds (64.1%) and sulfates (21.9%).NARSTO (formerly North American Research Strategy for Tropospheric Ozone) is a public/private partnership, whose membership spans government, the utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission is to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are available.

The NARSTO_EPA_SS_ST_LOUIS_AIR_CHEM_PM_MET_DATA were obtained between April 11, 2001 and July 21, 2003 during the St. Louis - Midwest Supersite program.The overall goal of the St. Louis - Midwest Supersite was to conduct aerosol physical and chemical measurements needed by the health effects community, the atmospheric science community and the regulatory community to properly assess the impact of particulate matter exposure on human health and to develop control strategies to mitigate these effects. Metropolitan St. Louis is a major population center well isolated from other urban centers of even moderate size, and is impacted by both distant and local sources. Local industry includes manufacturing,refining, and chemical plants. St. Louis is climatologically representative of the country's eastern interior, affected by a wide range of synoptic weather patterns and free of localized influences from the Great Lakes, Ocean, Gulf, and mountains. It accordingly provides an ideal environment for studying the sources, transport, and properties of ambient particles.The initial data types included:1) 5-minute PM 2.5 black carbon (880 nm) and uv-absorbing carbon (370 nm) measured by a Magee Scientific Aethalometer (Model AE-21).2) 1-hour PM 2.5 elemental carbon and blank-corrected organic carbon from semicontinuous thermo-optical analysis by the ACE-ASIA method.3) 24-hour PM 2.5 elemental carbon and organic carbon (both blank-corrected) from integrated filter with offline thermo-optical analysis by the ACE-ASIA method.4) 30-minute PM 2.5 metal composition from samples collected with a Semicontinuous Elements in Aerosol Sampler (SEAS) II.5) 5-minute meteorological data (wind, temperature, RH, solar radiation, atmospheric pressure, and precipitation) measured with a Climatronics anemometer, wind vane, thermocouple, lithium chloride sensor, pyranometer, barometer, and tipping bucket.6) 24-hour PM 1.0 filter mass concentration measured by sharp cut cyclone and gravimetric analysis.7) 1-hour PM 2.5 mass measured by an Andersen Continuous Ambient Mass Monitoring System (CAMMS).8) 24-hour PM 2.5 and PM 10 filter mass by Harvard Impactors and laboratory gravimetric analysis.The U.S. EPA Particulate Matter (PM) Supersites Program was an ambient air monitoring research program designed to provide information of value to the atmospheric sciences, and human health and exposure research communities. Eight geographically diverse projects were chosen to specifically address these EPA research priorities: (1) to characterize PM, its constituents, precursors, co-pollutants, atmospheric transport, and its source categories that affect the PM in any region; (2) to address the research questions and scientific uncertainties about PM source-receptor and exposure-health effects relationships; and (3) to compare and evaluate different methods of characterizing PM including testing new and emerging measurement methods. NARSTO (formerly North American Research Strategy for Tropospheric Ozone) is a public/private partnership, whose membership spans government, the utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission is to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are available.

The NARSTO_EPA_SS_HOUSTON_NH3_HNO3_is the North American Research Strategy for Tropospheric Ozone (NARSTO) Environmental Protection Agency (EPA) Supersite (SS) Houston, Ammonia and Nitric Acid Data product. It contains 24-hour integrated measurements of ammonia and nitric acid collected during September 30, 2000 through May 22, 2001 at the Houston Regional Monitoring (HRM) Site 3, Aldine, and Deer Park Houston Supersite monitoring locations. Samples were collected using a coated annular diffusion denuder downstream of a Teflon filter and analyzed by ion chromatography. Data set change history: Measurements of ammonia and nitric acid were quantified as ammonium and nitrate using ion chromatography. Effective August 27, 2004, the TABLE COLUMN NAME and TABLE COLUMN CAS IDENTIFIER values in the main data table were changed from ammonium and nitrate to ammonia and nitric acid to clarify that these are gas-phase measurements. The data set name was changed from NARSTO EPA_SS_HOUSTON Ammonium and Nitrate Data to NARSTO EPA_SS_HOUSTON Ammonia and Nitric Acid Data. No data values were changed. The Houston Supersite is one of several Supersites that was established in urban areas within the United States by the EPA to better understand the measurement, sources, and health effects of suspended particulate matter (PM). The overall goals were to characterize the composition and identify the sources of PM in Southeastern Texas, to develop and test new methods for characterizing fine PM, and to collect data on the physical and chemical characterization of fine PM that can be used to support exposure and health effects studies. NARSTO, which has since disbanded, was a public/private partnership, whose membership spanned across government, utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission was to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are still available.

The NARSTO_EPA_SS_HOUSTON_TEXAQS2000_PM25_ORG_DATA is North American Research Strategy for Tropospheric Ozone (NARSTO) Environmental Protection Agency (EPA) Supersite (SS) Houston, Texas Air Quality Study 2000 (TexAQS2000) Particulate Matter (PM) 2.5 Organic Speciation Data. This file contains 24-hour integrated organic speciation of fine particulate matter (PM2.5) collected August 15, 2000 through September 30, 2000 at the HRM Site 3, Aldine, and La Porte Houston Supersite monitoring locations during TexAQS2000. The filters were extracted with hexane and benzene: isopropanol. Polar compounds were analyzed after derivatization with either diazomethane or bis-trimethylsilyl-trifluoroacetamide. All compounds were quantified by gas chromatography-mass spectrometry. The Houston Supersite is one of several Supersites that was established in urban areas within the United States by the U.S. Environmental Protection Agency (EPA) to better understand the measurement, sources, and health effects of suspended particulate matter (PM). The overall goals were to characterize the composition and identify the sources of particulate matter in Southeastern Texas, to develop and test new methods for characterizing fine particulate matter, and to collect data on the physical and chemical characterization of fine particulate matter that can be used to support exposure and health effects studies.NARSTO, which has since disbanded, was a public/private partnership, whose membership spanned across government, utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission was to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are still available.

The NARSTO_EPA_SS_LOS_ANGELES_PM25_CARBON data were collected between January and May 2002. At Claremont (Los Angeles County, California), Cascaded Integrated Collection and Vaporization System for Particulate Carbon (ICVS for Carbon) was used in a mobile trailer to collect PM2.5 particulate carbon data during January 14, 2002 to May 24, 2002. The ICVS for Carbon measured PM2.5 particulate carbon data that cover sizes from 0.1-2.5um in every 10 minutes.The overall objective of the Los Angeles Supersite in Southern California Particle Center and Supersite (SCPCS) is to conduct monitoring and research that contributes to a better understanding of the measurement, sources, size distribution, chemical composition and physical state, spatial and temporal variability, and linkages to health effects of airborne particulate matter in the Los Angeles Basin.The U.S. EPA Particulate Matter (PM) Supersites Program was an ambient air monitoring research program designed to provide information of value to the atmospheric sciences, and human health and exposure research communities. Eight geographically diverse projects were chosen to specifically address these EPA research priorities: (1) to characterize PM, its constituents, precursors, co-pollutants, atmospheric transport, and its source categories that affect the PM in any region; (2) to address the research questions and scientific uncertainties about PM source-receptor and exposure-health effects relationships; and (3) to compare and evaluate different methods of characterizing PM including testing new and emerging measurement methods.NARSTO (formerly North American Research Strategy for Tropospheric Ozone) is a public/private partnership, whose membership spans government, the utilities, industry, and academe throughout Mexico, the United States, and Canada. The primary mission is to coordinate and enhance policy-relevant scientific research and assessment of tropospheric pollution behavior; activities provide input for science-based decision-making and determination of workable, efficient, and effective strategies for local and regional air-pollution management. Data products from local, regional, and international monitoring and research programs are available.