scholarly journals Comparison of Volatile Organic Compound Concentrations in Ambient Air among Different Source Areas around Khon Kaen, Thailand

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1694
Author(s):  
Pornpun Sakunkoo ◽  
Saksit Phonphinyo ◽  
Naowarat Maneenin ◽  
Chananya Jirapornkul ◽  
Yuparat Limmongkon ◽  
...  
Keyword(s):  
Fine Particulate Matter ◽  
Ground Level ◽  
Ambient Air ◽  
Monitoring Site ◽  
Vehicle Exhaust ◽  
Ground Level Ozone ◽  
Volatile Organic ◽  
Khon Kaen ◽  
Control Department ◽  
Rural Sites

Volatile organic compounds (VOCs) are a complex group of chemicals that pose a direct risk to human health. They also lead to the formation of other air pollution constituents, including fine particulate matter (PM2.5) and ground level ozone (O₃). The ambient air concentrations of 19 VOCs were measured using multi-day 24 h sampling at two urban sites and two rural sites in the area of Khon Kaen, Thailand. Results showed that most VOCs were at concentrations considered acceptable according to the 24 h average standards established by the Thai Pollution Control Department. The VOC acrolein, however, was detected at concentrations (0.69–1.15 μg/m3) in excess of the 24 h average standard (0.55 μg/m3). Two other VOCs, benzene and 1,3-butadiene, were also detected at elevated levels (1.73–2.75 and 0.18–0.40 μg/m3, respectively) that indicated the potential to exceed the 1-year average standard. VOC concentrations were highest in the urban market monitoring site, suggesting that vehicle exhaust and food preparation using cooking oil at high temperatures may have been potential sources of the elevated VOCs.

Association of Low-Level Ozone with Cognitive Decline in Older Adults

2021 ◽  
Author(s):  
Ekaterina Galkina Cleary ◽  
Manuel Cifuentes ◽  
Georges Grinstein ◽  
Doug Brugge ◽  
Thomas B. Shea
Keyword(s):  
Cognitive Decline ◽  
Environmental Protection Agency ◽  
Repeated Measures ◽  
Prolonged Exposure ◽  
Fine Particulate Matter ◽  
Ground Level ◽  
Ambient Air ◽  
Ground Level Ozone ◽  
Mixed Regression ◽  
Airborne Pollutant

Increasing evidence points to an association of airborne pollutant exposure with respiratory, cardiovascular, and neurological pathology. We examined whether or not ground-level ozone or fine particulate matter ≤ 2.5 μm in diameter (PM2.5) was associated with accelerated cognitive decline. Using repeated measures mixed regression modeling, we analyzed cognitive performance of a geographically diverse sampling of individuals from the National Alzheimer’s Coordinating Center between 2004–2008. Ambient air concentrations of ozone and PM2.5 were established using a space-time Hierarchical Bayesian Model that statistically merged air monitor data and modeled air quality estimates. We then compared the ambient regional concentrations of ozone and PM2.5 with the rate of cognitive decline in residents within those regions. Increased levels of ozone correlated with an increased rate of cognitive decline, following adjustment for key individual and community-level risk factors. Furthermore, individuals harboring one or more APOE4 alleles exhibited a faster rate of cognitive decline. The deleterious association of ozone was confined to individuals with normal cognition who eventually became cognitively impaired as opposed to those who entered the study with baseline impairment. In contrast to ozone, we did not observe any correlation between ambient PM2.5 and cognitive decline at regulatory limits set by the Environmental Protection Agency. Our findings suggest that prolonged exposure to ground-level ozone may accelerate cognitive decline during the initial stages of dementia development.

Considerations on Ambient Levels of Ozone Concentrations and Relationship with NOx in an Urban Environment

2017 ◽  
Vol 68 (4) ◽  
pp. 824-829
Author(s):  
Cornel Ianache ◽  
Laurentiu Predescu ◽  
Mirela Predescu ◽  
Dumitru Dumitru
Keyword(s):  
Nitrogen Oxides ◽  
Urban Areas ◽  
Road Traffic ◽  
Temporal Distribution ◽  
Ground Level ◽  
Distinct Pattern ◽  
Weekend Effect ◽  
Monitoring Site ◽  
Ground Level Ozone ◽  
Ozone Concentrations

The serious air pollution problem has determined public concerns, worldwide. One of the main challenges for countries all over the world is caused by the elevated levels of ground-level ozone (O3) concentrations and its anthropogenic precursors. Ploiesti city, as one of the major urban area of Romania, is facing the same situation. This research aims to investigate spatial and temporal distribution characteristics of O3 in relationship with nitrogen oxides (NOx) using statistical analysis methods. Hourly O3 and NOx measurements were collected during 2014 year in Ploiesti. The results obtained showed that the ozone spatial distribution was non-normal for each month in 2014. The diurnal cycle of ground-level ozone concentrations showed a mid-day peak, while NOx diurnal variations presented 2 daily peaks, one in the morning (7:00 a.m.) and one in the afternoon (between 5:00 and 7:00 p.m.). In addition, it was observed a distinct pattern of weekly variations for O3 and NOx. Like in many other urban areas, the results indicated the presence of the �ozone weekend effect� in Ploiesti during the 2014 year, ozone concentrations being slightly higher on weekends compared to weekdays. For the same monitoring site, the nitrogen oxides were less prevalent on Saturdays and Sundays, probably due to reducing of road traffic and other pollution-generating activities on weekends than during the week.

scholarly journals Ozone formation sensitivity study using machine learning coupled with reactivity of VOC species

2021 ◽  
Author(s):  
Junlei Zhan ◽  
Yongchun Liu ◽  
Wei Ma ◽  
Xin Zhang ◽  
Xuezhong Wang ◽  
...  
Keyword(s):  
Positive Response ◽  
Meteorological Factors ◽  
Ground Level ◽  
Sensitivity Study ◽  
Computationally Efficient ◽  
Timely Manner ◽  
Ground Level Ozone ◽  
Volatile Organic ◽  
Response To Temperature ◽  
Better Than

Abstract. The formation of ground-level ozone (O3) is dependent on both atmospheric chemical processes and meteorological factors. Traditional models have difficulty assessing O3 formation sensitivity in a timely manner due to the limitations of flexibility and computational efficiency. In this study, a random forest (RF) model coupled with the reactivity of volatile organic compound (VOC) species was used to investigate the O3 formation sensitivity in Beijing from 2014 to 2016, and evaluate the relative importance (RI) of chemical and meteorological factors to O3 formation. The results showed that the O3 prediction performance using initial concentrations of VOC species (R2 = 0.87) was better than that using total VOCs (TVOCs) concentrations (R2 = 0.77). Meanwhile, the RIs of VOC species correlated well with their O3 formation potentials (OFPs). O3 formation presented a negative response to NOx, PM2.5 and relative humidity, and a positive response to temperature, solar radiation and VOCs. The O3 isopleth curves calculated by the RF model were generally comparable with those calculated by the box model. O3 formation shifted from a VOC-limited regime to a transition regime from 2014 to 2016. This study demonstrates that the RF model coupled with the initial concentrations of VOC species could provide an accurate, flexible, and computationally efficient approach for O3 sensitivity analysis.

Regulating Transportation in New Nonattainment Areas Under the 8-Hour Ozone Standard

2003 ◽  
Vol 1842 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Jonathan Makler ◽  
Arnold M. Howitt
Keyword(s):  
North Carolina ◽  
Environmental Protection Agency ◽  
Ground Level ◽  
Ambient Air ◽  
Quality Standard ◽  
Ground Level Ozone ◽  
History Of ◽  
Ambient Air Quality Standard ◽  
Institutional Challenges ◽  
Transportation Agencies

The U.S. Environmental Protection Agency promulgated a new National Ambient Air Quality Standard for ground-level ozone in July 1997, beginning a process that (after some litigation-induced delays) will soon lead to the designation of new nonattainment areas that will be subject to the transportation conformity regulations. The history of the 8-h ozone standard is reviewed, the process of designating the boundaries of new nonattainment areas is described, and the types and geographic locations of the new nonattainment areas are suggested. Drawing on previous research, the institutional challenges that will face the new and expanded nonattainment areas are explored. The experiences of Georgia, North Carolina, and Oklahoma in preparing for implementation of the new standard are presented. Finally, several recommendations for transportation agencies involved in implementing the new standards are given.

Association of Air Pollutant Exposure and Sinonasal Histopathology Findings in Chronic Rhinosinusitis

2021 ◽  
pp. 194589242199365
Author(s):  
Tirth R. Patel ◽  
Bobby A. Tajudeen ◽  
Hannah Brown ◽  
Paolo Gattuso ◽  
Phillip LoSavio ◽  
...  
Keyword(s):  
Air Pollution ◽  
Chronic Rhinosinusitis ◽  
Air Pollutants ◽  
Ground Level ◽  
Ambient Air ◽  
Ozone Exposure ◽  
Ambient Air Pollution ◽  
Sinus Surgery ◽  
Ground Level Ozone ◽  
The Impact

Background Ambient air pollution is well known to cause inflammatory change in respiratory epithelium and is associated with exacerbations of inflammatory conditions such as asthma and chronic obstructive pulmonary disease. However, limited work has been done on the impact of air pollution on pathogenesis of chronic rhinosinusitis and there are no reports in the literature of how pollutant exposure may impact sinonasal histopathology in patients with chronic rhinosinusitis. Objective This study aims to identify associations between certain histopathologic characteristics seen in sinus tissue of patients with chronic rhinosinusitis (CRS) and levels of particulate air pollution (PM2.5) and ground-level ozone in their place of residence. Methods A structured histopathology report was created to characterize the tissues of CRS patients undergoing sinus surgery. An estimate for each patient’s exposure to air pollutants including small particulate matter (PM2.5) and ground-level ozone was obtained using the Environmental Protection Agency’s (EPA) Environmental Justice Screening and Mapping Tool (EJSCREEN). Mean pollutant exposures for patients whose tissues exhibited varying histopathologic features were compared using logistic regression models. Results Data from 291 CRS patients were analyzed. Higher degree of inflammation was significantly associated with increased ozone exposure (p = 0.031). Amongst the patients with CRSwNP (n=131), presence of eosinophilic aggregates (p = 0.018) and Charcot-Leyden crystals (p = 0.036) was associated with increased ozone exposure. Conclusion Exposure to ambient air pollutants may contribute to pathogenesis of CRS. Increasing ozone exposure was linked to both higher tissue inflammation and presence of eosinophilic aggregates and Charcot-Leyden crystals in CRSwNP patients.

scholarly journals Long-term measurements of ground-level ozone in Windsor, Canada – Part I. temporal variations and trends

2018 ◽  
Author(s):  
Xiaohong Xu ◽  
Tianchu Zhang ◽  
Yushan Su
Keyword(s):  
Ground Level ◽  
Temporal Variations ◽  
Control Measures ◽  
Ground Level Ozone ◽  
Ozone Formation Potential ◽  
Volatile Organic ◽  
Increasing Trend ◽  
Annual Means ◽  
Collaborative Efforts

Abstract. This study investigates temporal variations and long-term (1996–2015) trends of ground-level O3 (ozone) and its precursors, NOx (nitrogen oxides) and volatile organic compounds in Windsor, Ontario, Canada. During the 20-year study period, NOx, non-methane hydrocarbon concentrations and ozone formation potential decreased significantly by 58 %, 61 %, and 73 %, respectively, while O3 concentrations increased by 33 % (20.3 ppb in 1996 vs. 27 ppb in 2015). Our analysis revealed that the increased annual O3 concentrations in Windsor were due to (1) decreased O3 titration (by 50 % between 1996 and 2015) owing to declining nitric oxide concentrations, which is suggested by a slightly decreasing trend of annual mean total O3 concentrations after the titration effect is removed, (2) reduced local photochemical production of O3, because of dwindling precursor emissions, and (3) increased background O3 level that has more impact on the low-to-median concentrations. The net effect of those factors is decreasing peak O3 levels during the smog season from May to September, but an overall increasing trend of annual means. These results indicate that the emission control measures are effective in reducing peak ozone concentrations. However, challenges in lowering annual O3 levels call for long-term collaborative efforts in the region and around the globe.

scholarly journals Contribution of solvents from road marking paints to tropospheric ozone formation

2016 ◽  
Vol 15 (1) ◽  
pp. 007-018 ◽  
Author(s):  
Tomasz Burghardt ◽  
Anton Pashkevich ◽  
Lidia Żakowska
Keyword(s):  
Tropospheric Ozone ◽  
Western Europe ◽  
Ground Level ◽  
Solar Irradiation ◽  
Ozone Formation ◽  
Potential Contribution ◽  
Ground Level Ozone ◽  
Ozone Formation Potential ◽  
Volatile Organic ◽  
Road Marking

Solventborne road marking paints are meaningful sources of Volatile Organic Compounds (VOCs), which under solar irradiation affect formation of tropospheric ozone, a signif cant pulmonary irritant and a key pollutant responsible for smog formation. Influence of particular VOCs on ground-level ozone formation potential, quantified in Maximum Incremental Reactivities (MIR), were used to calculate potential contribution of solvents from road marking paints used in Poland to tropospheric ozone formation. Based on 2014 data, limited only to roads administered by General Directorate for National Roads and Motorways (GDDKiA), emissions of VOCs from road marking paints in Poland were about 494 838 kg, which could lead to production of up to 1 003 187 kg of ropospheric ozone. If aromatic-free solventborne paints based on ester solvents, such as are commonly used in Western Europe, were utilised, VOC emissions would not be lowered, but potentially formed ground-level ozone could be limited by 50-70%. Much better choice from the perspective of environmental protection would be the use of waterborne road marking paints like those mandated in Scandinavia – elimination of up to 82% of the emitted VOCs and up to 95% of the potentially formed tropospheric ozone could be achieved.

scholarly journals Volatile Organic Compound Analysis by Sorbent Tube-Thermal Desorption-Gas Chromatography: A Review

2018 ◽  
Vol 7 (3.14) ◽  
pp. 165
Author(s):  
Md Firoz Khan ◽  
Mazrura Sahani ◽  
Mohd Shahrul Mohd Nadzir ◽  
Lin Chin Yik ◽  
Hossain Mohammad Syedul Hoque ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Urban Areas ◽  
Ground Level ◽  
Ambient Air ◽  
Careful Consideration ◽  
Northeast Monsoon ◽  
Oxides Of Nitrogen ◽  
Ozone Pollution ◽  
Photochemical Pollution ◽  
Volatile Organic

Volatile organic compounds (VOCs) play an important role in the generation of ground level ozone and secondary organic aerosol. Most tropical countries such as Malaysia, Singapore, Indonesia, Brunei experience high ozone pollution. Beside ozone, oxides of nitrogen (NOx) from vehicular emissions also play an important role in photochemical pollution. NOx, particularly nitric oxide (NO), helps to ‘clean up’ ozone concentrations close to traffic in the ambient air of urban areas. Thus, knowledge of the chemistry of ozone-VOCs-NOx and finding the sources of VOCs are crucial to proceed with an appropriate mitigation strategy. Thus, the detection of ozone precursors and related VOCs is thoroughly discussed. This review finds that the inertness, hydrophobicity, and the effect of the artefact materials are very significant factors to be explored in the selection of the sorbent materials. In the SEA region, relative humidity is relatively high and exceeds 90% during the northeast monsoon. Thus, the hydrophobic properties of the sampling material need careful consideration. Further to the effect of relative humidity (RH), the artefact effect of the material itself is a challenge to be optimized and multi-sorbent material in a single tube could be a viable choice to minimize the effect of the unwanted signal in the spectrum.     

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