Volatile Organic Compounds in the atmosphere of the Great Athens area: The case of a port site close to Piraeus, Greece

2020 ◽  
Author(s):  
Eleni Liakakou ◽  
Anastasia Panopoulou ◽  
Georgios Grivas ◽  
Stéphane Sauvage ◽  
Theodora Kritikou ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Ambient Air ◽  
Road Transport ◽  
Pollution Monitoring ◽  
Low Wind Speed ◽  
General Terms ◽  
Volatile Organic ◽  
Transport Ship ◽  
The Impact

<p>VOCs are key atmospheric constituents for both health and climate issues and further knowledge is still needed about their sources and fate. The presence of volatile organic compounds in ambient air is strongly dependent on the site characteristics and a harbor area undergoes many source typologies such as road transport, ship emissions and contaminants of commercial activities, the shipbuilding zone and other operating facilities. The current work was implemented at the recently established Atmospheric Pollution Monitoring Station of the Municipality of Keratsini-Drapetsona located in the close vicinity of the Piraeus port. Since December 2018 an automatic gas chromatograph with flame ionization detector (FID) continuously monitors at a 30 minutes time resolution non methane hydrocarbons (NMHCs) focusing on hazardous compounds (aromatics) and strong precursors (aromatics, monoterpenes) of secondary pollutants like ozone and secondary organic aerosols. High levels of benzene were observed, especially during the morning to noon period, and the mean concentration of both benzene and toluene were two-folded in summer (July and August 2019) compared to winter (January and February 2019). Ethylbenzene follows the same pattern, whereas xylenes presented comparable levels during the cold and warm periods. Preliminary results based on source apportionment techniques are presented. In general terms the NMHC levels present their maximum under the impact of low wind speed, addressing thus the role of local emission sources, which are further investigated by the ratios used as tracking tools of processes of different origin (e.g. the traffic related ratio of toluene/benzene).</p>

scholarly journals Characteristics of marine shipping emissions at berth: profiles for particulate matter and volatile organic compounds

2018 ◽  
Vol 18 (13) ◽  
pp. 9527-9545 ◽  
Author(s):  
Qian Xiao ◽  
Mei Li ◽  
Huan Liu ◽  
Mingliang Fu ◽  
Fanyuan Deng ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mass Spectrometer ◽  
Elemental Carbon ◽  
Atmospheric Stability ◽  
Diesel Oil ◽  
Human Populations ◽  
Volatile Organic ◽  
Before And After ◽  
The Impact

Abstract. Emissions from ships at berth play an important role regarding the exposure of high density human populations to atmospheric pollutants in port areas; however, these emissions are not well understood. In this study, volatile organic compounds (VOCs) and particle emissions from 20 container ships at berth were sampled and analyzed during the “fuel switch” period at Jingtang Port in Hebei Province, China. VOCs and particles were analyzed using a gas chromatography-mass spectrometer (GC-MS) and a single particle aerosol mass spectrometer (SPAMS), respectively. VOC analysis showed that alkanes and aromatics, especially benzene, toluene and heavier compounds e.g., n-heptane, n-octane and n-nonane, dominated the total identified species. Secondary organic aerosol (SOA) yields and ozone (O3) forming potential were 0.017 ± 0.007 g SOA g−1 VOCs and 2.63 ± 0.37 g O3 g−1 VOCs, respectively. Both positive and negative ion mass spectra from individual ships were derived and the intensity of specific ions were quantified. Results showed that elemental carbon (35.74 %), elemental carbon–organic carbon mixtures (33.95 %) and Na-rich particles (21.12 %) were major classes, comprising 90.7 % of the particles observed. Particles from ship auxiliary engines were in the 0.2 to 2.5 µm size range, with a peak occurring at around 0.4 µm. The issue of using vanadium (V) as tracer element was examined, and it was found that V was not a proper tracer of ship emissions when using low sulfur content diesel oil. The average percentage of sulfate particles observed in shipping emissions before and after switching to marine diesel oil remained unchanged at 24 %. Under certain wind conditions, when berths were upwind of emission sources, the ratios before and after 1 January were 35 and 27 % respectively. The impact of atmospheric stability was discussed based on PM2.5 and primary pollutant (carbon monoxide) concentration. With a background of frequent haze episodes and complex mechanisms of particulate accumulation and secondary formation, the impact of atmospheric stability is believed to have been weak on the sulfate contribution from shipping emissions. The results from this study provide robust support for port area air quality assessment and source apportionment.

scholarly journals Sensitivity of biogenic volatile organic compounds to land surface parameterizations and vegetation distributions in California

2016 ◽  
Vol 9 (5) ◽  
pp. 1959-1976 ◽  
Author(s):  
Chun Zhao ◽  
Maoyi Huang ◽  
Jerome D. Fast ◽  
Larry K. Berg ◽  
Yun Qian ◽  
...  
Keyword(s):  
Air Quality ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Land Surface ◽  
Aerosol Formation ◽  
Biogenic Volatile Organic Compounds ◽  
Vegetation Map ◽  
Near Surface ◽  
Volatile Organic ◽  
The Impact

Abstract. Current climate models still have large uncertainties in estimating biogenic trace gases, which can significantly affect atmospheric chemistry and secondary aerosol formation that ultimately influences air quality and aerosol radiative forcing. These uncertainties result from many factors, including uncertainties in land surface processes and specification of vegetation types, both of which can affect the simulated near-surface fluxes of biogenic volatile organic compounds (BVOCs). In this study, the latest version of Model of Emissions of Gases and Aerosols from Nature (MEGAN v2.1) is coupled within the land surface scheme CLM4 (Community Land Model version 4.0) in the Weather Research and Forecasting model with chemistry (WRF-Chem). In this implementation, MEGAN v2.1 shares a consistent vegetation map with CLM4 for estimating BVOC emissions. This is unlike MEGAN v2.0 in the public version of WRF-Chem that uses a stand-alone vegetation map that differs from what is used by land surface schemes. This improved modeling framework is used to investigate the impact of two land surface schemes, CLM4 and Noah, on BVOCs and examine the sensitivity of BVOCs to vegetation distributions in California. The measurements collected during the Carbonaceous Aerosol and Radiative Effects Study (CARES) and the California Nexus of Air Quality and Climate Experiment (CalNex) conducted in June of 2010 provided an opportunity to evaluate the simulated BVOCs. Sensitivity experiments show that land surface schemes do influence the simulated BVOCs, but the impact is much smaller than that of vegetation distributions. This study indicates that more effort is needed to obtain the most appropriate and accurate land cover data sets for climate and air quality models in terms of simulating BVOCs, oxidant chemistry and, consequently, secondary organic aerosol formation.

scholarly journals Seasonal and Spatial Variation of Volatile Organic Compounds in Ambient Air of Almaty City, Kazakhstan

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1592
Author(s):  
Olga P. Ibragimova ◽  
Anara Omarova ◽  
Bauyrzhan Bukenov ◽  
Aray Zhakupbekova ◽  
Nassiba Baimatova
Keyword(s):  
Air Pollution ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Power Plants ◽  
Ambient Air ◽  
Spatial Variations ◽  
Primary Sources ◽  
Volatile Organic ◽  
Seasonal And Spatial Variations ◽  
Before And After

Air pollution is one of the primary sources of risk to human health in the world. In this study, seasonal and spatial variations of multiple volatile organic compounds (VOCs) were measured at six sampling sites in Almaty, Kazakhstan. The seasonal and spatial variations of 19 VOCs were evaluated in 2020, including the periods before and after COVID-19 lockdown. The concentrations of 9 out of 19 VOCs had been changed significantly (p < 0.01) during 2020. The maximum concentrations of total VOCs (TVOCs) were observed on 15, 17, and 19 January and ranged from 233 to 420 µg m−3. The spatial distribution of TVOCs concentrations in the air during sampling seasons correlated with the elevation and increased from southern to northern part of Almaty, where Combined Heat and Power Plants are located. The sources of air pollution by VOCs were studied by correlations analysis and BTEX ratios. The ranges of toluene to benzene ratio and benzene, toluene, and ethylbenzene demonstrated two primary sources of BTEX in 2020: traffic emissions and biomass/biofuel/coal burning. Most of m-, p-xylenes to ethylbenzene ratios in this study were lower than 3 in all sampling periods, evidencing the presence of aged air masses at studied sampling sites from remote sources.

scholarly journals Underway seawater and atmospheric measurements of volatile organic compounds in the Southern Ocean

2020 ◽  
Vol 17 (9) ◽  
pp. 2593-2619 ◽  
Author(s):  
Charel Wohl ◽  
Ian Brown ◽  
Vassilis Kitidis ◽  
Anna E. Jones ◽  
William T. Sturges ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Southern Ocean ◽  
Organic Compounds ◽  
Dimethyl Sulfide ◽  
Ambient Air ◽  
Atmospheric Measurements ◽  
Mixing Ratios ◽  
Volatile Organic ◽  
Air Mixing ◽  
Net Flux

Abstract. Dimethyl sulfide and volatile organic compounds (VOCs) are important for atmospheric chemistry. The emissions of biogenically derived organic gases, including dimethyl sulfide and especially isoprene, are not well constrained in the Southern Ocean. Due to a paucity of measurements, the role of the ocean in the atmospheric budgets of atmospheric methanol, acetone, and acetaldehyde is even more poorly known. In order to quantify the air–sea fluxes of these gases, we measured their seawater concentrations and air mixing ratios in the Atlantic sector of the Southern Ocean, along a ∼ 11 000 km long transect at approximately 60∘ S in February–April 2019. Concentrations, oceanic saturations, and estimated fluxes of five simultaneously sampled gases (dimethyl sulfide, isoprene, methanol, acetone, and acetaldehyde) are presented here. Campaign mean (±1σ) surface water concentrations of dimethyl sulfide, isoprene, methanol, acetone, and acetaldehyde were 2.60 (±3.94), 0.0133 (±0.0063), 67 (±35), 5.5 (±2.5), and 2.6 (±2.7) nmol dm−3 respectively. In this dataset, seawater isoprene and methanol concentrations correlated positively. Furthermore, seawater acetone, methanol, and isoprene concentrations were found to correlate negatively with the fugacity of carbon dioxide, possibly due to a common biological origin. Campaign mean (±1σ) air mixing ratios of dimethyl sulfide, isoprene, methanol, acetone, and acetaldehyde were 0.17 (±0.09), 0.053 (±0.034), 0.17 (±0.08), 0.081 (±0.031), and 0.049 (±0.040) ppbv. We observed diel changes in averaged acetaldehyde concentrations in seawater and ambient air (and to a lesser degree also for acetone and isoprene), which suggest light-driven production. Campaign mean (±1σ) fluxes of 4.3 (±7.4) µmol m−2 d−1 DMS and 0.028 (±0.021) µmol m−2 d−1 isoprene are determined where a positive flux indicates from the ocean to the atmosphere. Methanol was largely undersaturated in the surface ocean with a mean (±1σ) net flux of −2.4 (±4.7) µmol m−2 d−1, but it also had a few occasional episodes of outgassing. This section of the Southern Ocean was found to be a source and a sink for acetone and acetaldehyde this time of the year, depending on location, resulting in a mean net flux of −0.55 (±1.14) µmol m−2 d−1 for acetone and −0.28 (±1.22) µmol m−2 d−1 for acetaldehyde. The data collected here will be important for constraining the air–sea exchange, cycling, and atmospheric impact of these gases, especially over the Southern Ocean.

scholarly journals Target Analysis of Volatile Organic Compounds in Exhaled Breath for Lung Cancer Discrimination from Other Pulmonary Diseases and Healthy Persons

Metabolites ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 317
Author(s):  
Michalis Koureas ◽  
Paraskevi Kirgou ◽  
Grigoris Amoutzias ◽  
Christos Hadjichristodoulou ◽  
Konstantinos Gourgoulianis ◽  
...  
Keyword(s):  
Machine Learning ◽  
Computed Tomography ◽  
Lung Cancer ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Ambient Air ◽  
Breath Analysis ◽  
Exhaled Breath ◽  
Healthy Controls ◽  
Volatile Organic

The aim of the present study was to investigate the ability of breath analysis to distinguish lung cancer (LC) patients from patients with other respiratory diseases and healthy people. The population sample consisted of 51 patients with confirmed LC, 38 patients with pathological computed tomography (CT) findings not diagnosed with LC, and 53 healthy controls. The concentrations of 19 volatile organic compounds (VOCs) were quantified in the exhaled breath of study participants by solid phase microextraction (SPME) of the VOCs and subsequent gas chromatography-mass spectrometry (GC-MS) analysis. Kruskal–Wallis and Mann–Whitney tests were used to identify significant differences between subgroups. Machine learning methods were used to determine the discriminant power of the method. Several compounds were found to differ significantly between LC patients and healthy controls. Strong associations were identified for 2-propanol, 1-propanol, toluene, ethylbenzene, and styrene (p-values < 0.001–0.006). These associations remained significant when ambient air concentrations were subtracted from breath concentrations. VOC levels were found to be affected by ambient air concentrations and a few by smoking status. The random forest machine learning algorithm achieved a correct classification of patients of 88.5% (area under the curve—AUC 0.94). However, none of the methods used achieved adequate discrimination between LC patients and patients with abnormal computed tomography (CT) findings. Biomarker sets, consisting mainly of the exogenous monoaromatic compounds and 1- and 2- propanol, adequately discriminated LC patients from healthy controls. The breath concentrations of these compounds may reflect the alterations in patient’s physiological and biochemical status and perhaps can be used as probes for the investigation of these statuses or normalization of patient-related factors in breath analysis.

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