scholarly journals Effects of emission reductions on organic aerosol in the southeastern United States

2016 ◽  
Vol 16 (1) ◽  
pp. 215-238 ◽  
Author(s):  
C. L. Blanchard ◽  
G. M. Hidy ◽  
S. Shaw ◽  
K. Baumann ◽  
E. S. Edgerton
Keyword(s):  
Biomass Burning ◽  
Motor Vehicle ◽  
Organic Aerosol ◽  
Combustion Products ◽  
Emission Reductions ◽  
Southeastern Us ◽  
Motor Vehicle Emissions ◽  
Combustion Processes ◽  
The City

Abstract. Long-term (1999 to 2013) data from the Southeastern Aerosol Research and Characterization (SEARCH) network are used to show that anthropogenic emission reductions led to important decreases in fine-particle organic aerosol (OA) concentrations in the southeastern US On average, 45 % (range 25 to 63 %) of the 1999 to 2013 mean organic carbon (OC) concentrations are attributed to combustion processes, including fossil fuel use and biomass burning, through associations of measured OC with combustion products such as elemental carbon (EC), carbon monoxide (CO), and nitrogen oxides (NOx). The 2013 mean combustion-derived OC concentrations were 0.5 to 1.4 µg m−3 at the five sites operating in that year. Mean annual combustion-derived OC concentrations declined from 3.8 ± 0.2 µg m−3 (68 % of total OC) to 1.4 ± 0.1 µg m−3 (60 % of total OC) between 1999 and 2013 at the urban Atlanta, Georgia, site (JST) and from 2.9 ± 0.4 µg m−3 (39 % of total OC) to 0.7 ± 0.1 µg m−3 (30 % of total OC) between 2001 and 2013 at the urban Birmingham, Alabama (BHM), site. The urban OC declines coincide with reductions of motor vehicle emissions between 2006 and 2010, which may have decreased mean OC concentrations at the urban SEARCH sites by > 2 µg m−3. BHM additionally exhibits a decline in OC associated with SO2 from 0.4 ± 0.04 µg m−3 in 2001 to 0.2 ± 0.03 µg m−3 in 2013, interpreted as the result of reduced emissions from industrial sources within the city. Analyses using non-soil potassium as a biomass burning tracer indicate that biomass burning OC occurs throughout the year at all sites. All eight SEARCH sites show an association of OC with sulfate (SO4) ranging from 0.3 to 1.0 µg m−3 on average, representing  ∼  25 % of the 1999 to 2013 mean OC concentrations. Because the mass of OC identified with SO4 averages 20 to 30 % of the SO4 concentrations, the mean SO4-associated OC declined by  ∼  0.5 to 1 µg m−3 as SO4 concentrations decreased throughout the SEARCH region. The 2013 mean SO4 concentrations of 1.7 to 2.0 µg m−3 imply that future decreases in mean SO4-associated OC concentrations would not exceed  ∼  0.3 to 0.5 µg m−3. Seasonal OC concentrations, largely identified with ozone (O3), vary from 0.3 to 1.4 µg m−3 ( ∼  20 % of the total OC concentrations).

scholarly journals Effects of emission reductions on organic aerosol in the southeastern United States

2015 ◽  
Vol 15 (12) ◽  
pp. 17051-17092 ◽  
Author(s):  
C. L. Blanchard ◽  
G. M. Hidy ◽  
S. Shaw ◽  
K. Baumann ◽  
E. S. Edgerton
Keyword(s):  
Biomass Burning ◽  
Motor Vehicle ◽  
Organic Aerosol ◽  
Combustion Products ◽  
Emission Reductions ◽  
Southeastern Us ◽  
Motor Vehicle Emissions ◽  
Combustion Processes ◽  
The City

Abstract. Long-term (1999 to 2013) data from the Southeastern Aerosol Research and Characterization (SEARCH) network are used to characterize the effects of anthropogenic emission reductions on fine particle organic aerosol (OA) concentrations in the southeastern US. On average, 45 % (range 25 to 63 %) of the 1999 to 2013 mean organic carbon (OC) concentrations are attributed to combustion processes, including fossil-fuel use and biomass burning, through associations of measured OC with combustion products such as elemental carbon (EC), carbon monoxide (CO), and nitrogen oxides (NOx). The 2013 mean combustion-derived OC concentrations were 0.5 to 1.4 μg m−3 at the five sites operating in that year. Mean annual combustion-derived OC concentrations declined from 3.8 ± 0.2 μg m−3 (68 % of total OC) to 1.4 ± 0.1 μg m−3 (60 % of total OC) between 1999 and 2013 at the urban Atlanta, Georgia, site (JST) and from 2.9 ± 0.4 μg m−3 (39 % of total OC) to 0.7 ± 0.1 μg m−3 (30 % of total OC) between 2001 and 2013 at the urban Birmingham, Alabama, site (BHM). The urban OC declines coincide with reductions of motor-vehicle emissions between 2006 and 2010, which may have decreased mean OC concentrations at the urban SEARCH sites by > 2 μg m−3. BHM additionally exhibits a decline in OC associated with SO2 from 0.4 ± 0.04 μg m−3 in 2001 to 0.2 ± 0.03 μg m−3 in 2013, interpreted as the result of reduced emissions from industrial sources within the city. Analyses using non-soil potassium as a biomass-burning tracer indicate that biomass-burning OC occurs throughout the year at all sites. All eight SEARCH sites show an association of OC with sulfate (SO4) ranging from 0.3 to 1.0 μg m−3 on average, representing ~ 25 % of the 1999 to 2013 mean OC concentrations. Because the mass of OC associated with SO4 averages 20 to 30 % of the SO4 concentrations, the mean SO4-associated OC declined by ~ 0.5 to 1 μg m−3 as SO4 decreased throughout the SEARCH region. The 2013 mean SO4 concentrations of 1.7 to 2.0 μg m−3 imply that future decreases in mean SO4-associated OC concentrations would not exceed ~ 0.3 to 0.5 μg m−3. Seasonal OC concentrations, largely associated with ozone (O3), vary from 0.3 to 1.4 μg m−3 (~ 20 % of the total OC concentrations).

Long-Term Trends in Motor Vehicle Emissions in U.S. Urban Areas

2013 ◽  
Vol 47 (17) ◽  
pp. 10022-10031 ◽  
Author(s):  
Brian C. McDonald ◽  
Drew R. Gentner ◽  
Allen H. Goldstein ◽  
Robert A. Harley
Keyword(s):  
Urban Areas ◽  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Motor Vehicle Emissions ◽  
Long Term Trends

scholarly journals Ozone response to emission reductions in the southeastern United States

2018 ◽  
Vol 18 (11) ◽  
pp. 8183-8202 ◽  
Author(s):  
Charles L. Blanchard ◽  
George M. Hidy
Keyword(s):  
Environmental Protection Agency ◽  
Study Data ◽  
Nox Emissions ◽  
Emission Rates ◽  
Emission Reductions ◽  
Mixing Ratios ◽  
Southeastern Us ◽  
Surface Measurements ◽  
Nitrate Deposition

Abstract. Ozone (O3) formation in the southeastern US is studied in relation to nitrogen oxide (NOx) emissions using long-term (1990s–2015) surface measurements of the Southeastern Aerosol Research and Characterization (SEARCH) network, U.S. Environmental Protection Agency (EPA) O3 measurements, and EPA Clean Air Status and Trends Network (CASTNET) nitrate deposition data. Annual fourth-highest daily peak 8 h O3 mixing ratios at EPA monitoring sites in Georgia, Alabama, and Mississippi exhibit statistically significant (p < 0.0001) linear correlations with annual NOx emissions in those states between 1996 and 2015. The annual fourth-highest daily peak 8 h O3 mixing ratios declined toward values of ∼ 45–50 ppbv and monthly O3 maxima decreased at rates averaging ∼ 1–1.5 ppbv yr−1. Mean annual total oxidized nitrogen (NOy) mixing ratios at SEARCH sites declined in proportion to NOx emission reductions. CASTNET data show declining wet and dry nitrate deposition since the late 1990s, with total (wet plus dry) nitrate deposition fluxes decreasing linearly in proportion to reductions of NOx emissions by ∼ 60 % in Alabama and Georgia. Annual nitrate deposition rates at Georgia and Alabama CASTNET sites correspond to 30 % of Georgia emission rates and 36 % of Alabama emission rates, respectively. The fraction of NOx emissions lost to deposition has not changed. SEARCH and CASTNET sites exhibit downward trends in mean annual nitric acid (HNO3) concentrations. Observed relationships of O3 to NOz (NOy–NOx) support past model predictions of increases in cycling of NO and increasing responsiveness of O3 to NOx. The study data provide a long-term record that can be used to examine the accuracy of process relationships embedded in modeling efforts. Quantifying observed O3 trends and relating them to reductions in ambient NOy species concentrations offers key insights into processes of general relevance to air quality management and provides important information supporting strategies for reducing O3 mixing ratios.

scholarly journals BIOMONITORING PENCEMARAN UDARA MENGGUNAKAN BIOINDIKATOR LICHENES DI KOTA MADIUN

2015 ◽  
Vol 2 (2) ◽  
Author(s):  
Anikhotul Ihrom ◽  
Ani Sulistyarsi
Keyword(s):  
Air Pollution ◽  
Atomic Absorption ◽  
Random Sampling ◽  
Air Pollutants ◽  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Sampling Technique ◽  
Motor Vehicle Emissions ◽  
Lead In Air ◽  
The City

Bioindicators can be used to determine levels of air pollution of an area by analyzing the content of pollutants lead in bioindicators. Lichenes growing on the bark as bioindicators for measuring the concentration of lead in air pollutants resulting from motor vehicle emissions. The aim of research to determine differences in the levels of lead (Pb) using bioindicators Lichenes Madiun. Samples were taken by random sampling technique. Pb content measurement using Atomic Absorption Spectrophotometer (AAS). The results showed Pb levels in different areas of the City of Madiun there are significant differences. Traffic levels affect the levels of Pb .

Review of Urban Secondary Organic Aerosol Formation from Gasoline and Diesel Motor Vehicle Emissions

2017 ◽  
Vol 51 (3) ◽  
pp. 1074-1093 ◽  
Author(s):  
Drew R. Gentner ◽  
Shantanu H. Jathar ◽  
Timothy D. Gordon ◽  
Roya Bahreini ◽  
Douglas A. Day ◽  
...  
Keyword(s):  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Aerosol Formation ◽  
Motor Vehicle Emissions ◽  
Secondary Organic Aerosol Formation

scholarly journals Molecular Markers in Ambient Air Associated with Biomass Burning in Morelos, México

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 491
Author(s):  
Mónica Ivonne Arias-Montoya ◽  
Rebecca López-Márquez ◽  
Mario Alfonso Murillo-Tovar ◽  
Jorge Antonio Guerrero-Alvarez ◽  
Josefina Vergara-Sánchez ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Forest Fires ◽  
Glutaric Acid ◽  
Dicarboxylic Acids ◽  
Ambient Air ◽  
Organic Aerosol ◽  
Photochemical Activity ◽  
Aerodynamic Diameter ◽  
Positive Correlations ◽  
The City

Atmospheric particles with an aerodynamic diameter less than or equal to 2.5 micrometers (PM2.5) were collected at two sites located in the urban area of the city of Cuernavaca (Morelos) during a season when a large number of forest fires occurred. Three dicarboxylic acids (malonic, glutaric and succinic) and levoglucosan were analyzed by liquid chromatography coupled with mass spectrometry (ESI-Q-TOF) and soluble potassium (K+) was analyzed by ion chromatography. The concentration of PM2.5 increased on the days when the highest number of forest fires occurred. A strong correlation was observed between levoglucosan and K+, confirming the hypothesis that both are tracers of biomass burning (r = 0.57, p < 0.05). Levoglucosan (average 367.6 ng m−3, Site 2) was the most abundant compound, followed by succinic acid (average 101.7 ng m−3, Site 2), glutaric acid (average 63.2 ng m−3, Site 2), and malonic acid (average 46.9 ng m−3, Site 2), respectively. The ratio of C3/C4 concentrations ranged from 0.5 to 1.2, with an average of 0.8, which suggests great photochemical activity in the Cuernavaca atmosphere. The ratio of K+/levoglucosan concentrations (0.44) indicates that open fires are the main source of these tracers. The positive correlations between PM2.5 and levoglucosan and succinic and malonic acids suggest that such compounds are contributing to secondary organic aerosol particle formation.

scholarly journals Secondary Organic Aerosol Formation from in-Use Motor Vehicle Emissions Using a Potential Aerosol Mass Reactor

2014 ◽  
Vol 48 (19) ◽  
pp. 11235-11242 ◽  
Author(s):  
Daniel S. Tkacik ◽  
Andrew T. Lambe ◽  
Shantanu Jathar ◽  
Xiang Li ◽  
Albert A. Presto ◽  
...  
Keyword(s):  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Aerosol Formation ◽  
Aerosol Mass ◽  
Motor Vehicle Emissions ◽  
Secondary Organic Aerosol Formation

scholarly journals Kadar Logam Timbal (Pb) dalam Darah Penjual Klepon

2017 ◽  
Vol 3 (2) ◽  
pp. 47
Author(s):  
Yayuk Kustiningsih ◽  
Noni Fitriyanti ◽  
Nurlailah Nurlailah
Keyword(s):  
Motor Vehicle ◽  
Negative Impact ◽  
Blood Lead ◽  
Combustion Products ◽  
Lead In Blood ◽  
Cross Sectional ◽  
Motor Vehicle Emissions ◽  
Lead Metal ◽  
Cross Sectional Design ◽  
Descriptive Survey

<p style="text-align: justify;">A kelepon seller is one of the groups susceptible to metal pollution from motor vehicle emissions from the tetraethyl-Pb and tetramethyl-Pb combustion products that are always added to motor vehicle fuel. Lead metal has a negative impact on the environment including human health. The first effect of chronic Pb poisoning before reaching the target organ is the presence of hemoglobin synthesis disorder so that the hemoglobin level decreases.The effect of lead poisoning in the blood can occur if the Pb content is more 70 ug/dl or 0.7 ppm which will lead to anemia. This study aims to determine a level of lead metal in the blood of kelepon seller that exceeds the threshold. Descriptive survey research method with cross-sectional design on the sample from 15 respondents. The lead metal (Pb) in the blood is measured using an Atomic Absorption Spectrophotometer (SSA) device. The result of the research shows that there are 13 respondents (86,7%) whose Pb metal content exceeds the blood lead threshold that is 20 ug / dL or 0,20 ppm. The highest level of lead in the blood of the respondents was 0.73 ppm and the lowest was 0.10 ppm. Two respondents with lead in blood less than 0.20 ppm are known to always use personal protective equipment while working, even though the working time is 6-10 hours/day. It is advisable to conduct further research by examining Hb levels and abnormalities of erythrocytes in the blood of the kelepon seller and conducting similar research </p>

scholarly journals A new method for long-term source apportionment with time-dependent factor profiles and uncertainty assessment using SoFi Pro: application to one year of organic aerosol data

2020 ◽  
Author(s):  
Francesco Canonaco ◽  
Anna Tobler ◽  
Gang Chen ◽  
Yulia Sosedova ◽  
Jay Gates Slowik ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Biomass Burning ◽  
Organic Aerosol ◽  
Uncertainty Assessment ◽  
Aerosol Mass ◽  
Concentration Peak ◽  
Rolling Window ◽  
Improved Performance ◽  
One Year

Abstract. A new methodology for performing long-term source apportionment (SA) using positive matrix factorization (PMF) is presented. The method is implemented within the SoFi Pro software package and uses the multilinear engine (ME-2) as a PMF solver. The technique is applied to a one-year aerosol chemical speciation monitor (ACSM) dataset from downtown Zurich, Switzerland. The measured organic aerosol mass spectra were analyzed by PMF using a small (14 days) and rolling PMF window to account for the temporal evolution of the sources. The rotational ambiguity is explored and the uncertainty of the PMF solutions were estimated. Factor/tracer correlations for averaged seasonal results from the rolling window analysis are higher than those retrieved from conventional PMF analyses of individual seasons, highlighting the improved performance of the rolling window algorithm for long-term data. In this study four to five-factors were tested for every PMF window. Factor profiles for primary organic aerosol from traffic (HOA), cooking (COA) and biomass burning (BBOA) were constrained. Secondary organic aerosol was represented by either the combination of semi-volatile and low-volatility organic aerosol (SV-OOA and LV-OOA, respectively), or by a single OOA when this separation was not robust. This scheme leads to roughly 40 000 PMF runs. Full visual inspection of all these PMF runs is unrealistic and is replaced by predefined user-selected criteria, which allow factor sorting and PMF run acceptance/rejection. The selected criteria for traffic (HOA) and biomass burning (BBOA) were the correlation with equivalent black carbon (eBCtr) and the explained variation of m/z 60, respectively. COA was assessed by the prominence of a lunchtime concentration peak within the diurnal cycle. SV-OOA and LV-OOA were evaluated based on the fraction of m/z 43 and m/z 44 in their respective factor profiles. Seasonal pre-tests revealed a non-continuous separation of OOA into SV-OOA and LV-OOA, in particular during the warm seasons. Therefore, a differentiation between four-factor solutions (HOA, COA, BBOA and OOA) and five-factor solutions (HOA, COA, BBOA, SV-OOA and LV-OOA) was also conducted based on the criterion for SV-OOA. HOA and COA contribute between 0.4–0.7 μg m−3 (7.8–9.0 %) and 0.7–1.2 μg m−3 (12.2–15.7 %) on average throughout the year, respectively. BBOA shows a strong yearly cycle with the lowest mean concentrations in summer (0.6 μg m−3, 12.0 %), slightly higher mean concentrations during spring and fall (1.0 and 1.5 μg m−3, or 15.6 and 18.6 %, respectively), and highest mean concentrations during winter (1.9 μg m−3, 25.0 %). In summer, OOA is separated into SV-OOA and LV-OOA, with mean concentrations of 1.4 μg m−3 (26.5 %) and 2.2 μg m−3 (40.3 %), respectively. For the remaining seasons the seasonal concentrations of SV-OOA, LV-OOA and OOA range from 0.3–1.1 μg m−3 (3.4–15.9 %), 0.6–2.2 μg m−3 (7.7–33.7 %) and 0.9–3.1 μg m−3 (13.7–39.9 %), respectively. The relative PMF errors modelled for this study for HOA, COA, BBOA, LV-OOA, SV-OOA and OOA are on average ±34 %, ±27 %, ±30, ±11 %, ±25 % and ±12 %, respectively.

scholarly journals Aerosol characterization over the southeastern United States using high resolution aerosol mass spectrometry: spatial and seasonal variation of aerosol composition, sources, and organic nitrates

2015 ◽  
Vol 15 (7) ◽  
pp. 10479-10552 ◽  
Author(s):  
L. Xu ◽  
S. Suresh ◽  
H. Guo ◽  
R. J. Weber ◽  
N. L. Ng
Keyword(s):  
Seasonal Variation ◽  
Organic Aerosol ◽  
Organic Nitrates ◽  
Short Term ◽  
Brown Carbon ◽  
Aerosol Mass ◽  
Southeastern Us ◽  
Rural Sites ◽  
Urban Sites

Abstract. We deployed a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and an Aerosol Chemical Speciation Monitor (ACSM) to characterize the chemical composition of submicron non-refractory particles (NR-PM1) in the southeastern US. Measurements were performed in both rural and urban sites in the greater Atlanta area, GA and Centreville, AL for approximately one year, as part of Southeastern Center of Air Pollution and Epidemiology study (SCAPE) and Southern Oxidant and Aerosol Study (SOAS). Organic aerosol (OA) accounts for more than half of NR1 mass concentration regardless of sampling sites and seasons. Positive matrix factorization (PMF) analysis of HR-ToF-AMS measurements identified various OA sources, depending on location and season. Hydrocarbon-like OA (HOA) and cooking OA (COA) have important but not dominant contributions to total OA in urban sites. Biomass burning OA (BBOA) concentration shows a distinct seasonal variation with a larger enhancement in winter than summer. We find a good correlation between BBOA and brown carbon, indicating biomass burning is an important source for brown carbon, although an additional, unidentified brown carbon source is likely present at the rural Yorkville site. Isoprene-derived OA (Isoprene-OA) is only deconvolved in warmer months and contributes 18–36% of total OA. The presence of Isoprene-OA factor in urban sites is more likely from local production in the presence of NOx than transport from rural sites. More-oxidized and less-oxidized oxygenated organic aerosol (MO-OOA and LO-OOA, respectively) are dominant fractions (47–79%) of OA in all sites. MO-OOA correlates well with ozone in summer, but not in winter, indicating MO-OOA sources may vary with seasons. LO-OOA, which reaches a daily maximum at night, correlates better with estimated nitrate functionality from organic nitrates than total nitrates. Based on the HR-ToF-AMS measurements, we estimate that the nitrate functionality from organic nitrates contributes 63–100% of total measured nitrates in summer. Further, the contribution of organic nitrates to total OA is estimated to be 5–12% in summer, suggesting that organic nitrates are important components in the ambient aerosol in the southeastern US. The spatial distribution of OA is investigated by comparing simultaneous HR-ToF-AMS measurements with ACSM measurements at two different sampling sites. OA is found to be spatially homogeneous in summer, possibly due to stagnant air mass and a dominant amount of regional SOA in the southeastern US. The homogeneity is less in winter, which is likely due to spatial variation of primary emissions. We observed that the seasonality of OA concentration shows a clear urban/rural contrast. While OA exhibits weak seasonal variation in the urban sites, its concentration is higher in summer than winter for rural sites. This observation from our year-long measurements is consistent with 14 years of organic carbon (OC) data from the SouthEastern Aerosol Research and Characterization (SEARCH) network. The comparison between short-term measurements with advanced instruments and long-term measurements of basic air quality indicators not only tests the robustness of the short-term measurements but also provides insights in interpreting long-term measurements. We find that OA factors resolved from PMF analysis on HR-ToF-AMS measurements have distinctly different diurnal variations. The compensation of OA factors with different diurnal trends is one possible reason for the repeatedly observed, relatively flat OA diurnal profile in the southeastern US. In addition, analysis of long-term measurements shows that the correlation between OC and sulfate is substantially higher in summer than winter. This seasonality could be partly due to the effects of sulfate on isoprene SOA formation as revealed by the short-term, intensive measurements.

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