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1.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(6): 981-986, 2021 Nov.
Article in Chinese | MEDLINE | ID: mdl-34841765

ABSTRACT

Objective: To explore the health risks of the interactive effects between PM2.5 and ozone on cardiovascular mortality in Chengdu. Methods: Daily data on the mortality of cardiovascular diseases, including data for both men and women, during 2014-2016 were collected. The meteorological data, the daily average of particulate matter with aerodynamic diameter less than 2.5 micrometers (PM2.5), and the daily ozone 8 h maximum concentration (O 3 8-h max) in Chengdu of the same period were also collected. Generalized Additive Models (GAMs) were adopted to explore the respective adverse health effects of PM2.5 and O 3 8-h max and the synergistic effects between PM2.5 and O 3 8-h max on the mortality of cardiovascular diseases in the city. Results: The highest health risks of PM2.5 and O 3 8-h max for mortality of cardiovascular diseases were found to be the strongest for the cumulative effect of the lag of one day (lag01). For every 10 µg/m 3 increment in the mass concentration of PM2.5 (lag01), the associated increase in risks for total, male, and female cardiovascular mortalities was 0.35%, 0.26% and 0.38%, respectively. For every 10 µg/m 3 increment in the mass concentration of O 3 8-h max (lag01), the associated increase in risks for total, male, and female cardiovascular mortalities was 0.66%, 0.43%, and 1.05%, respectively. The total, male, and female cardiovascular mortalities all reached their maximum values when high concentration of PM2.5 coexisted with high concentrations of O 3 8-h max. Conclusion: There was a synergistic amplification effect between high concentrations of PM2.5 and high concentrations of O 3 8-h max on cardiovascular mortality.


Subject(s)
Air Pollutants , Cardiovascular Diseases , Ozone , Air Pollutants/adverse effects , Cardiovascular Diseases/etiology , China/epidemiology , Environmental Exposure/adverse effects , Female , Humans , Male , Ozone/adverse effects , Ozone/analysis , Particulate Matter/adverse effects
2.
Environ Monit Assess ; 193(12): 844, 2021 Nov 27.
Article in English | MEDLINE | ID: mdl-34837538

ABSTRACT

Bengaluru, also considered India's Silicon Valley, has seen steady growth in population over the years. Bengaluru's rapid development has resulted in dwindling reservoirs, increased traffic congestion, high levels of air pollution, and, to some measure, a rise in summer temperatures. As a result of these changes in urban form over the last decade, anthropogenic heat fluxes for ozone production have increased. However, an observational study on the effects of growing urbanisation on trace gases in Bengaluru for various seasons and periods of the day is missing. Hence, in situ measurements of O3, NO, NO2, and NOX concentrations were carried out at Bengaluru, India, from January 2015 to December 2018. The data were examined for diurnal and interannual variations in trace gas mixing concentrations. The diurnal trend in O3 exhibits unimodal behaviour. Changes in photochemistry, local meteorology, and the planetary boundary layer's distinctive features cause a rise in the value of concentrations and lead to a peak. In contrast, the diurnal trend in NO, NO2, and NOX displayed a bimodal peak due to the combined effect of vehicular emissions and the planetary boundary layer. The link involving the oxidant OX (O3 + NO2) and NOx levels were investigated to determine the NOx-independent regional and NOx-dependent local contributions to OX in the atmosphere. Daytime contributions are higher than night-time contributions, according to the present study. The observed anomalies could be the consequence of photochemical processes that produce OX.


Subject(s)
Air Pollutants , Air Pollution , Ozone , Air Pollutants/analysis , Air Pollution/analysis , Environmental Monitoring , India , Nitrogen , Nitrogen Oxides/analysis , Oxides , Ozone/analysis , Seasons
3.
Sensors (Basel) ; 21(22)2021 Nov 10.
Article in English | MEDLINE | ID: mdl-34833532

ABSTRACT

Methane is a major greenhouse gas and a precursor of tropospheric ozone, and most of its sources are linked to anthropogenic activities. The sources of methane are well known and its monitoring generally involves the use of expensive gas analyzers with high operating costs. Many studies have investigated the use of low-cost gas sensors as an alternative for measuring methane concentrations; however, it is still an area that needs further development to ensure reliable measurements. In this work a low-cost platform for measuring methane within a low concentration range was developed and used in two distinct environments to continuously assess and improve its performance. The methane sensor was the Figaro TGS2600, a metal oxide semiconductor (MOS) based on tin dioxide (SnO2). In a first stage, the monitoring platform was applied in a small ruminant barn after undergoing a multi-point calibration. In a second stage, the system was used in a wastewater treatment plant together with a multi-gas analyzer (Gasera One Pulse). The calibration of low-cost sensor was based on the relation of the readings of the two devices. Temperature and relative humidity were also measured to perform corrections to minimize the effects of these variables on the sensor signal and an active ventilation system was used to improve the performance of the sensor. The system proved to be able to measure low methane concentrations following reliable spatial and temporal patterns in both places. A very similar behavior between both measuring systems was also well noticeable at WWTP. In general, the low-cost system presented good performance under several environmental conditions, showing itself to be a good alternative, at least as a screening monitoring system.


Subject(s)
Methane , Ozone , Calibration , Semiconductors , Temperature
4.
Sci Total Environ ; 805: 150418, 2022 Jan 20.
Article in English | MEDLINE | ID: mdl-34818816

ABSTRACT

Carcinogenic N, N-Dimethylnitrosamine (NDMA) has been reported to generate significantly during ozonation of fuel additive unsymmetrical dimethylhydrazine (UDMH), the combined ozone/Peroxy-Monosulfate (O3/PMS) technology was tried for reducing its formation in this study. The influence of PMS dosages, ozone concentrations, pH, Br- and humic acid (HA) on NDMA formation from UDMH were investigated. In addition, the reduction mechanisms were explored by intermediates identification and Gaussian calculation. The results demonstrated that O3/PMS technology was effective on NDMA reduction, reaching an efficiency of 81% with 80 µM PMS. Higher NDMA reduction rates were achieved by O3/PMS with increasing pH within the scope of research (from 5 to 9), achieving a maximum of 69.9% at pH 9. The presence of bromide ion facilitated NDMA generation during ozonation, but the reduction efficiency by O3/PMS slightly improved from 66.3% to 70.6%. The presence of HA reduced NDMA formation in O3/PMS system. The contribution of SO4•- on NDMA reduction accounted for ~64%, which was higher than that of •OH (41.4%); however, its promotion role on conversing UDMH to NDMA was lower than O3. Therefore, the technology could reduce NDMA formation effectively. In addition, the results of Gaussian calculation manifested that the N atom in -NH2 group of UDMH was easily attacked not only by •OH but also by O3, so it is the key path that determines final NDMA formation. This study would provide reference for reducing NDMA formation during ozonation of UDMH-containing water matrixes.


Subject(s)
Ozone , Water Pollutants, Chemical , Water Purification , Dimethylhydrazines , Dimethylnitrosamine , Oxidation-Reduction , Technology , Water Pollutants, Chemical/analysis
5.
Braz Dent J ; 32(4): 19-30, 2021.
Article in English | MEDLINE | ID: mdl-34787248

ABSTRACT

This study investigated the bleaching effectiveness and the physicochemical effects on enamel of violet light and ozone, associate or not to hydrogen peroxide, compared to 35%-hydrogen peroxide. Enamel-dentin blocks from human molars were randomly allocated to receive one of the following bleaching protocols (n=15): (HP) 35%-hydrogen peroxide, (VL) violet light, (OZ) ozone, the association between hydrogen peroxide with ozone (OZ+HP) or violet light (VL+HP). All protocols were performed in two sessions with a 48h interval. Color (spectrophotometer) and mineral composition (Raman spectroscopy) were measured before and after the bleaching. Color changes were calculated by ΔEab, ΔE00, and whitening index (WI). The surface roughness was measured with an atomic force microscope. Data were analyzed by One-way or Two-way repeated measure ANOVA followed by the Tukey's test (α = 0.05). The lowest color change values (either measured by WI, ΔEab, or ΔE00) were observed for VL and OZ used with no HP. Violet light associate with HP was unable to improve the color changes observed for the peroxide alone, in combination with OZ and HP, the highest color changes were verified. Regardless of bleaching protocol, the bleached enamel presented higher contents of PO4 and CO3 -2 than those observed at baseline. All bleaching protocols resulted in similar enamel surface roughness. Both the VL and the OZ caused reduced effects on the enamel color change when used alone. The ozone therapy improved the bleaching effect in the group that received the association of HP.


Subject(s)
Ozone , Tooth Bleaching Agents , Tooth Bleaching , Color , Dental Enamel , Humans , Hydrogen Peroxide
6.
Environ Monit Assess ; 193(12): 808, 2021 Nov 16.
Article in English | MEDLINE | ID: mdl-34783908

ABSTRACT

The plant response to elevated ozone stress reveals inter-species and intra-species disparity. Ozone-induced crop yield loss is predicted to increase in the future, posing a threat to the world economy. This study aims to evaluate the cultivar specific variation in rice exposed to elevated ozone. Fifteen short-duration rice cultivars were exposed to 50 ppb ozone for 30 days at reproductive stage. The physiological, biochemical, growth and yield traits of all test cultivars were significantly affected in response to elevated ozone. On an average, ozone stress decreased the tiller number by 22.52%, number of effective tillers by 30.43%, 1000 grain weight by 0.62% and straw weight by 23.83% over control. Spikelet sterility increased by 19.26% and linear multiregression 3D model significantly fits the spikelet sterility and photosynthetic traits with the R2 of 0.74 under elevated ozone. Principal Component Analysis with total variance of 57.5% categorized 15 rice cultivars into four major groups, i.e., ozone sensitive (MDU6, TRY(R)2 and ASD16), moderately ozone sensitive (ASD18, ADT43, and MDU5), moderately ozone tolerant (ADT37, ADT(R)45, TPS5, Anna(R)4, PMK(R)3, and ADT(R)48), and ozone tolerant (CO51, CO47, and ADT36). This study indicates that the different responses of rice cultivars to elevated ozone stress through a change in plant physiology, biochemical, growth, and yield traits and the results directed to provide scientific information on plant adaptations to ozone stress and helps in efforts to search ozone tolerant gene for plant breeding.


Subject(s)
Oryza , Ozone , Edible Grain , Environmental Monitoring , Ozone/toxicity , Plant Breeding
7.
Int J Environ Res Public Health ; 18(21)2021 11 05.
Article in English | MEDLINE | ID: mdl-34770158

ABSTRACT

Health effects related to exposure to air pollution such as ozone (O3) have been documented. The World Health Organization has recommended the use of the Sum of O3 Means Over 35 ppb (SOMO35) to perform Health Impact Assessments (HIA) for long-term exposure to O3. We estimated the avoidable mortality associated with long-term exposure to tropospheric O3 in 14 cities in Mexico using information for 2015. The economic valuation of avoidable deaths related to SOMO35 exposure was performed using the willingness to pay (WTP) and human capital (HC) approaches. We estimated that 627 deaths (95% uncertainty interval (UI): 227-1051) from respiratory diseases associated with the exposure to O3 would have been avoided in people over 30 years in the study area, which confirms the public health impacts of ambient air pollution. The avoidable deaths account for almost 1400 million USD under the WTP approach, whilst the HC method yielded a lost productivity estimate of 29.7 million USD due to premature deaths. Our findings represent the first evidence of the health impacts of O3 exposure in Mexico, using SOMO35 metrics.


Subject(s)
Air Pollutants , Air Pollution , Ozone , Air Pollutants/analysis , Air Pollutants/toxicity , Air Pollution/analysis , Air Pollution/statistics & numerical data , Environmental Exposure , Humans , Mexico/epidemiology , Ozone/analysis , Ozone/toxicity , Particulate Matter/analysis
8.
Environ Monit Assess ; 193(12): 790, 2021 Nov 11.
Article in English | MEDLINE | ID: mdl-34762170

ABSTRACT

This study presents the characteristics of ground level atmospheric ozone (O3) over the rural mid-Brahmaputra Valley region of the northeastern India. Ozone and oxides of nitrogen (NOx = NO + NO2) concentration data were obtained from continuous measurement of O3 and NOx housed at the MAPAN-AQM station at Tezpur University. The meteorological parameters were obtained from the same station. The diel, monthly, and seasonal variations of O3 were studied. The O3-NOx photostationary state (PS) was carefully examined and it was found that the net O3 concertation deviated substantially from the PS during the winter season. The deviation could be attributed to local biomass burning, biogenic VOC emission from forest and agriculture, and long-range transport of peroxyacyl nitrate (PAN). The long-range transport has been ascertained by examining the ventilation coefficients (VC), which correlated with the steep growth of net O3 concentrations in the morning hours. The HYSPLIT air mass back trajectories were used in concentration-weighted trajectory (CWT) analyses of O3 to assess the long-range regional transport of O3 precursors, which positively influenced local O3 concentrations.


Subject(s)
Air Pollutants , Ozone , Air Pollutants/analysis , Environmental Monitoring , Humans , India , Nitrogen Oxides/analysis , Ozone/analysis
9.
Proc Natl Acad Sci U S A ; 118(46)2021 11 16.
Article in English | MEDLINE | ID: mdl-34753820

ABSTRACT

The COVID-19 global pandemic and associated government lockdowns dramatically altered human activity, providing a window into how changes in individual behavior, enacted en masse, impact atmospheric composition. The resulting reductions in anthropogenic activity represent an unprecedented event that yields a glimpse into a future where emissions to the atmosphere are reduced. Furthermore, the abrupt reduction in emissions during the lockdown periods led to clearly observable changes in atmospheric composition, which provide direct insight into feedbacks between the Earth system and human activity. While air pollutants and greenhouse gases share many common anthropogenic sources, there is a sharp difference in the response of their atmospheric concentrations to COVID-19 emissions changes, due in large part to their different lifetimes. Here, we discuss several key takeaways from modeling and observational studies. First, despite dramatic declines in mobility and associated vehicular emissions, the atmospheric growth rates of greenhouse gases were not slowed, in part due to decreased ocean uptake of CO2 and a likely increase in CH4 lifetime from reduced NO x emissions. Second, the response of O3 to decreased NO x emissions showed significant spatial and temporal variability, due to differing chemical regimes around the world. Finally, the overall response of atmospheric composition to emissions changes is heavily modulated by factors including carbon-cycle feedbacks to CH4 and CO2, background pollutant levels, the timing and location of emissions changes, and climate feedbacks on air quality, such as wildfires and the ozone climate penalty.


Subject(s)
Air Pollution , Atmosphere/chemistry , COVID-19/psychology , Greenhouse Gases , Models, Theoretical , COVID-19/epidemiology , Carbon Dioxide , Climate Change , Humans , Methane , Nitrogen Oxides , Ozone
10.
Neurologia (Engl Ed) ; 36(9): 673-680, 2021.
Article in English | MEDLINE | ID: mdl-34752345

ABSTRACT

INTRODUCTION: Chronic exposure to low doses of ozone causes oxidative stress and loss of regulation of the inflammatory response, leading to progressive neurodegeneration. OBJECTIVE: We studied the effect of chronic exposure to low doses of ozone on IL-17A concentration and expression in neurons, microglia, astrocytes, and T cells in the rat hippocampus. METHODS: We used 72 Wistar rats, divided into 6 groups (n=12): a control group (no ozone exposure) and 5 groups exposed to ozone (0.25ppm, 4h daily) for 7, 15, 30, 60, and 90 days. We processed 6 rats from each group to quantify IL-17A by ELISA; the remaining 6 were processed for immunohistochemistry (against IL-17A and GFAP, Iba1, NeuN, and CD3). RESULTS: The ELISA study data showed a significant increase in IL-17A concentrations in the 7-, 15-, 30-, and 60-day exposure groups, with regard to the control group (P<.05). Furthermore, they indicate that hippocampal neurons were the cells showing greatest immunoreactivity against IL-17A between 60 and 90 days of exposure to ozone; we also observed an increase in activated astrocytes in the 30- and 60-day exposure groups. CONCLUSION: Exposure to ozone in rats induces an increase in IL-17A expression, mainly in hippocampal neurons, accompanied by hippocampal astrocyte activation during chronic neurodegeneration, similar to that observed in Alzheimer disease in humans.


Subject(s)
Hippocampus , Interleukin-17 , Ozone , Animals , Hippocampus/metabolism , Interleukin-17/metabolism , Microglia/metabolism , Ozone/adverse effects , Rats , Rats, Wistar
11.
Environ Monit Assess ; 193(12): 782, 2021 Nov 09.
Article in English | MEDLINE | ID: mdl-34751845

ABSTRACT

The water discarded from the quarantine station inspecting aquatic products can be served as an influx channel of invasive microorganisms to our own ecosystem. This study thus compared the viability of three different pathogenic bacteria (Escherichia coli, Vibrio harveyi, and Enterococcus faecalis) in either seawater or freshwater after their disinfection. For that, they were treated by ozonation (2.08 mM of ozone), ultraviolet irradiation (UVC-254), or thermal treatment (90℃) for 10 min, during which their resultant viability was monitored using colorimetric ATP assay, colony counting, and real-time quantitative RT-PCR. From this, ATP measurement and real-time quantitative RT-PCR have proved to be a much stronger correlation built in the fraction of each of their assays versus the colony counting, although they differed in the type of disinfection implemented. Especially, ATP assay was the most sensitively influenced by high levels of total residual oxidants (TRO) undesirably produced during the ozonation of V. harveyi and E. faecalis in seawater, although easily and shortly measured within 1 h, with higher accuracy. Aside from that, the real-time quantitative RT-PCR had a stronger correlation versus either that of seawater ozonation or thermal treatment. It is decided referring to measurement time and convenience in the field that ATP assay can be more reliably used in bacterial cell viability measurement in the quarantine after the ozonation in seawater to specifically allow the bacterial deactivation, not to overwhelmingly produce TRO due to the residual ozone provided.


Subject(s)
Ozone , Vibrio , Water Purification , Disinfection , Ecosystem , Environmental Monitoring , Microbial Viability , Oxidants , Quarantine , Water
12.
Environ Pollut ; 292(Pt B): 118454, 2022 Jan 01.
Article in English | MEDLINE | ID: mdl-34737024

ABSTRACT

Measurements of vertical distribution of volatile organic compounds (VOCs) have attracted wide attentions, which could help to understand atmospheric oxidation mechanism and provide implications for VOC control. This study measured the non-methane hydrocarbons (NMHCs) and oxygenated VOCs (OVOCs) simultaneously for the first time at three different heights, namely ground, 118 m and 488 m, in the Canton Tower located in the urban core of the Pearl River Delta (PRD). The results show that NMHCs decreased while some OVOC species such as formaldehyde and acetaldehyde increased with increasing height. It was mainly attributed to the dilution and chemical loss of NMHCs but secondary production of OVOCs during vertical transport. Ratio analysis and receptor modeling indicate that vehicle exhausts (47%) and fuel evaporation (39%) were major sources of the total NMHCs. Interestingly, industry contributed much more at 118 m, probably affected by organic gas discharge from the high chimney of industrial factories. The chemical reactivities in terms of OH radical loss rate (LOH), ozone formation potential (OFP) and secondary organic aerosol potential (SOAP) were lowest at 118 m, smaller than those influenced by high fresh NMHC emissions at ground and strong formation of secondary species (e.g. OVOCs) at 488 m. OH exposure estimated by isoprene and m,p-xylene/ethylbenzene was different depending on their time scale of vertical turbulent mixing and chemical loss. OVOC species measured at different heights were positively correlated with Ox (R = 0.48-0.87), indicating that OVOCs were largely contributed by secondary formation in photochemical process. The tower measurements of NMHCs and OVOCs provided a unique opportunity to investigate the VOC distribution and chemical behaviors, which could give important information for understanding O3 and PM2.5 pollution mechanism in the PRD region with fast developing urban setting and substantially changing air quality.


Subject(s)
Air Pollutants , Ozone , Volatile Organic Compounds , Air Pollutants/analysis , China , Environmental Monitoring , Hydrocarbons/analysis , Methane , Ozone/analysis , Rivers , Volatile Organic Compounds/analysis
13.
Sci Rep ; 11(1): 21336, 2021 10 29.
Article in English | MEDLINE | ID: mdl-34716393

ABSTRACT

Air quality improvements pollution changes due to COVID-19 restrictions have been reported for many urban developments and large metropolitan areas, but the respective impacts at rural and remote zones are less frequently analysed. This study evaluated air pollution changes across all Portugal (68 stations) considering all urban, suburban and rural zones. PM10, PM2.5, NO2, SO2, ozone was analysed in pre-, during, and post-lockdown period (January-May 2020) and for a comparison also in 2019. NO2 was the most reduced pollutant in 2020, which coincided with decreased traffic. Significant drop (15-71%) of traffic related NO2 was observed specifically during lockdown period, being 55% for the largest and most populated region in country. PM was affected to a lesser degree (with substantial differences found for largely populated areas (Lisbon region ~ 30%; North region, up to 49%); during lockdown traffic-related PM dropped 10-70%. PM10 daily limit was exceeded 50% less in 2020, with 80% of exceedances before lockdown period. SO2 decreased by 35%, due to suspended industrial productions, whereas ozone concentrations slightly (though not significantly) increased (83 vs. 80 µg m-3).


Subject(s)
Air Pollution/analysis , COVID-19/prevention & control , Quarantine/methods , Rural Population , SARS-CoV-2 , Suburban Population , Urban Population , Air Pollutants/analysis , COVID-19/epidemiology , COVID-19/virology , Environmental Monitoring/methods , Humans , Nitrogen Dioxide/analysis , Ozone/analysis , Particulate Matter/analysis , Portugal/epidemiology , Sulfur Dioxide/analysis
14.
Chemosphere ; 285: 131355, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34710962

ABSTRACT

Volatile organic compounds (VOCs) are widely recognized to affect the environment and human health. This review provides a comprehensive presentation of the types and levels of VOCs, their sources and potential effects on human health and the environment based on past and current observations made at tropical sites. Isoprene was found to be the dominant biogenic VOC in the tropics. Tropical broad leaf evergreen trees are the main emitters of isoprene, making up more than 70% of the total emissions. The VOCs found in the tropical remote marine atmosphere included isoprene (>100 ppt), dimethyl sulfide (≤100 ppt) and halocarbons, i.e. bromoform (≤8.4 ppt), dibromomethane (≤2.7 ppt) and dibromochloromethane (≤1.6 ppt). VOCs such as benzene, toluene, ethylbenzene and xylene (BTEX) are the most monitored anthropogenic VOCs and are present mainly due to motor vehicles emissions. Additionally, biomass burning contributes to anthropogenic VOCs, especially high molecular weight VOCs, e.g. methanol and acetonitrile. The relative contributions of VOC species to ozone are determined through the level of the Ozone Formation Potential (OFP) of different species. Emissions of VOCs (e.g. very short-lived halogenated gases) in the tropics are capable of contributing to stratospheric ozone depletion. BTEX has been identified as the main types of VOCs that are associated with the cancer risk in urban areas in tropical regions. Finally, future studies related to VOCs in the tropics and their associated health risks are needed to address these concerns.


Subject(s)
Air Pollutants , Ozone , Volatile Organic Compounds , Air Pollutants/analysis , China , Environmental Monitoring , Humans , Ozone/analysis , Toluene/analysis , Volatile Organic Compounds/analysis
15.
PLoS One ; 16(10): e0256324, 2021.
Article in English | MEDLINE | ID: mdl-34710139

ABSTRACT

Because of the continuous rise of foodborne illnesses caused by the consumption of raw fruits and vegetables, effective post-harvest anti-microbial strategies are necessary. The aim of this study was to evaluate the anti-microbial efficacy of ozone (O3) against two common causes of fresh produce contamination, the Gram-negative Escherichia coli O157:H7 and Gram-positive Listeria monocytogenes, and to relate its effects to potential mechanisms of xenobiosis by transcriptional network modeling. The study on non-host tomato environment correlated the dose × time aspects of xenobiosis by examining the correlation between bacterial survival in terms of log-reduction and defense responses at the level of gene expression. In E. coli, low (1 µg O3/g of fruit) and moderate (2 µg O3/g of fruit) doses caused insignificant reduction in survival, while high dose (3 µg/g of fruit) caused significant reduction in survival in a time-dependent manner. In L. monocytogenes, moderate dose caused significant reduction even with short-duration exposure. Distinct responses to O3 xenobiosis between E. coli and L. monocytogenes are likely related to differences in membrane and cytoplasmic structure and components. Transcriptome profiling by RNA-Seq showed that primary defenses in E. coli were attenuated after exposure to a low dose, while the responses at moderate dose were characterized by massive upregulation of pathogenesis and stress-related genes, which implied the activation of defense responses. More genes were downregulated during the first hour at high dose, with a large number of such genes getting significantly upregulated after 2 hr and 3 hr. This trend suggests that prolonged exposure led to potential adaptation. In contrast, massive downregulation of genes was observed in L. monocytogenes regardless of dose and exposure duration, implying a mechanism of defense distinct from that of E. coli. The nature of bacterial responses revealed by this study should guide the selection of xenobiotic agents for eliminating bacterial contamination on fresh produce without overlooking the potential risks of adaptation.


Subject(s)
Anti-Bacterial Agents/pharmacology , Escherichia coli O157/drug effects , Foodborne Diseases/prevention & control , Listeria monocytogenes/drug effects , Lycopersicon esculentum/microbiology , Ozone/pharmacology , Bacterial Load/drug effects , Food Microbiology , Foodborne Diseases/microbiology , Fruit/microbiology , Gene Expression Profiling , Gene Expression Regulation, Bacterial/drug effects , Microbial Viability/drug effects , Proof of Concept Study , RNA, Bacterial/genetics , RNA-Seq , Transcriptome/drug effects , Transcriptome/genetics , Vegetables/microbiology
16.
Huan Jing Ke Xue ; 42(11): 5075-5085, 2021 Nov 08.
Article in Chinese | MEDLINE | ID: mdl-34708947

ABSTRACT

Ground-level ozone pollution(O3) and climate change have become key global problems threatening the environment and sustainable development of urban forests. At present, various studies have assessed the O3 impacts on trees; however, it is difficult to accurately evaluate the complex ecological effects caused by multiple factors on the natural urban environment. In this paper, the interactions between O3 and carbon dioxide(CO2), drought, nitrogen deposition, and warming, as well as the effects of the physiology, biochemistry, and growth of urban trees in China were reviewed. Elevated CO2 could alleviate the negative effects of elevated O3 on the photosynthetic metabolism, antioxidant system, and growth of trees. There is a complex interaction between O3 and drought, which may synergistically aggravate, alleviate, or have no effect on trees. However, there was no correlation between O3 and N deposition, only a significant interaction between elevated temperatures and O3, which slowed down the adverse effects of O3 on tree growth and photosynthesis. Finally, suggestions are put forward to manage and sustainable develop urban forests in China under future climate change and air pollution.


Subject(s)
Air Pollution , Ozone , Air Pollution/adverse effects , China , Forests , Ozone/toxicity , Plant Leaves , Trees
17.
Huan Jing Ke Xue ; 42(11): 5162-5168, 2021 Nov 08.
Article in Chinese | MEDLINE | ID: mdl-34708955

ABSTRACT

A volatile organic compounds(VOCs) emission source classification and accounting system from domestic sources in China was established for the period between 2010 and 2018. Suggestions for the prevention and treatment of VOCs from domestic sources were developed and proposed. The results showed that the total VOCs emission inventory from domestic sources in China in 2018 was 2518 kt. Architectural decoration, asphalt road paving, cooking, and rural household biomass use source were the four largest contributors, accounting for 69.22% of the total emissions. Chemical household products and urban and rural coal use contributed equally, accounting for 10.43% and 9.98%, respectively, whilst car repair accounted for 7.75%. Shandong, Sichuan, Henan, Guangdong, Jiangsu, and Hebei were the six provinces that contributed the most(36.01%). During the 2010-2018 period, China's domestic VOCs emissions increased at a rate of 0.43%, and after reaching a peak in 2013, the emissions began to decline at a rate of 2.23%. The reason for the decline was that, on the one hand, the cleaner energy consumption of residents made a contribution to the gradual reduction of domestic coal and biomass consumption. On the other hand, the gradual saturation of housing construction in some areas, which led to a decrease in the annual construction of the country. It is recommended to promote the comprehensive management of architectural decoration, cooking methods, and car repair, while paying attention to the VOCs emissions from asphalt road paving. Meanwhile, continue to optimize the energy use structure of domestic sources, and promote the pollution control of civil coal and household biomass combustion in accordance with local regulations and multiple measures.


Subject(s)
Air Pollutants , Ozone , Volatile Organic Compounds , Air Pollutants/analysis , China , Environmental Monitoring , Ozone/analysis , Volatile Organic Compounds/analysis
18.
Huan Jing Ke Xue ; 42(11): 5193-5200, 2021 Nov 08.
Article in Chinese | MEDLINE | ID: mdl-34708958

ABSTRACT

The emission characteristics of VOCs from three typical rubber manufacture industries were studied by GC-MS/FID. Maximum incremental reactivity(MIR) and fractional aerosol coefficient(FAC) were employed to evaluate the ozone formation potential(OFP) and secondary organic aerosol(SOA) formation potential. The results show that the VOC types emitted from the manufacturing of rubber products mainly include alkanes, ketones, aldehydes, alcohols, and benzene series. For traditional rubber products manufactured through rubber mixing and vulcanization, the main pollutants are ketones and alcohols, whereas for production processes involving gluing and painting, the main pollutants belong to the benzene series. In terms of ozone impact, the traditional processes contribute to ozone formation mainly through oxygenated hydrocarbons. In industries that utilize adhesives and paints, the extensive use of these organic solvents lead to a significantly higher contribution of the benzene series than other VOC species to ozone formation; the benzene series account for 82.9% of the total contribution. In terms of SOA impact, the benzene series are the main contributor to SOA, whereas the contribution of VOCs from traditional processes is small; hence, SOA primarily originates from the gluing and painting processes. Therefore, in traditional production of rubber products through rubber mixing and vulcanization, the emission of oxygenated hydrocarbons should be preferentially controlled, whereas for rubber industries utilizing gluing and painting processes, the emission of benzene series should be preferentially controlled.


Subject(s)
Air Pollutants , Ozone , Volatile Organic Compounds , Air Pollutants/analysis , China , Environmental Monitoring , Ozone/analysis , Rubber , Volatile Organic Compounds/analysis
19.
Huan Jing Ke Xue ; 42(11): 5180-5192, 2021 Nov 08.
Article in Chinese | MEDLINE | ID: mdl-34708957

ABSTRACT

In recent years, fine particulate matter(PM2.5) and ozone(O3) have become the main air pollutants in cities in China. Volatile organic compounds(VOCs) are one of the important precursors of PM2.5, O3, and secondary organic aerosols. The establishment of VOCs emission inventory is therefore of great significance for controlling the amount of PM2.5 and O3. To date, the coefficient method has been used, which has error transmission of activity level, parameter and model, leading to the uncertainty of emission inventory. Multivariate uncertainty quantitative analysis of VOCs emission inventory provides an accurate alternative which has not been reported in China. The bottom-up method is adopted to collect the activity level of each enterprise. The variables of pollution control measures are obtained from surveys conducted with enterprises. The VOCs emission inventory of Qingdao from industrial source is established using an optimized coefficient method. The uncertainty of the VOCs inventory on the impact of univariate and multivariate variables is simulated by combining the Monte Carlo method(MC) with Latin hypercube sampling method(LHS). The results show that the total VOCs emissions were 44700 tons from industrial sources in 2019(unoptimized coefficient method:31100 tons).The rubber and plastic industries, metal products, and oil/coal/other fuel processing contributed more VOCs, which accounted for 40.26% of the total emissions. The uncertainty of multivariate simulation is higher than that of single variable. The uncertainty from process(-9.72%-230.51%) and solvent using source(-14.14%-122.77%) is significantly higher than uncertainty from combustion source(-15.62%-36.41%). The main sectors affecting the uncertainty of the VOCs inventory include:the chemical, papermaking, and textile industries(emission factors); metal, automobile manufacturing, and chemical industries(removal rate, facility operating rate); industries of petroleum processing and ferrous metal smelting(too few samples). VOCs emissions are mainly distributed in the east of the West Coast New district, north of Dazhu Mountain, south of Jimo district, north of Chengyang district, northeast of Jiaozhou district, built-up area of Pingdu district, and southeast of Laixi district.


Subject(s)
Air Pollutants , Ozone , Volatile Organic Compounds , Air Pollutants/analysis , China , Environmental Monitoring , Monte Carlo Method , Ozone/analysis , Uncertainty , Volatile Organic Compounds/analysis
20.
Huan Jing Ke Xue ; 42(11): 5201-5209, 2021 Nov 08.
Article in Chinese | MEDLINE | ID: mdl-34708959

ABSTRACT

Ambient volatile organic compounds(VOCs) were determined by GC 5000 online gas chromatography in three functional areas of Shenyang, namely industrial, traffic, and mixed cultural and educational areas. The pollution characteristics of VOCs in these functional areas during the heating and non-heating periods were analyzed, and the ozone formation potential(OFP) was estimated by using maximum incremental reactivity(MIR). The results show that the average mass concentration of VOCs is(82.19±54.99) µg·m-3 in Shenyang, of which the concentration in industrial areas is significantly higher than that in traffic and cultural and educational mixed areas, and the heating period is higher. The traffic and mixed cultural and educational areas have bi-modal characteristics due to the morning and evening traffic, and the industrial area has multiple peaks affected by the irregular operation hours. The proportion of VOCs in traffic and mixed cultural and educational areas shows the order of alkanes>aromatic hydrocarbons>alkenes>alkynes, but the proportion of alkynes in industrial areas is higher than that of alkenes. The benzene to toluene(B/T) and ethane to acetylene(E/A) ratios reflects that traffic and mixed cultural and educational areas were affected by both vehicle exhaust emissions and fuel combustion. The industrial zone is therefore affected by complex sources, and there are more aged air masses during the heating period than non-heating period. The average OFP contribution of atmospheric VOCs in Shenyang is 232.89 µg·m-3. The contribution of alkenes is largest for all functional areas, and the aromatic component also contributes more due to the high concentration of industrial areas.


Subject(s)
Air Pollutants , Ozone , Volatile Organic Compounds , Air Pollutants/analysis , China , Environmental Monitoring , Ozone/analysis , Vehicle Emissions/analysis , Volatile Organic Compounds/analysis
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