Trends of surface ozone based on hourly concentrations in the Beijing–Tianjin–Hebei region during 2017–2021

As a typical secondary air pollutant,surface ozone has been monitored routinely since 2013 in China.Most studies on the spatiotemporal variation of ozone have been centered around the daily maximum 8-h average,with little attention paid to the trends of hourly ozone,especially hourly ozone exceedances.Focusing on hourly ozone exceedances and peak values,the spatiotemporal trends of hourly ozone at 77 sites in 13 cities of the Beijing-Tianjin-Hebei(BTH)region during 2017-2021 were analyzed in this study.The number of hours with exceedances(N_(H200))in 2019 was nearly three times that of 2021.On a five-year average,the percentage of cumulative NH200 in June accounted for up to 40.5%of all hourly exceedances.Cities in central Hebei Province had the highest cumulative annual N_(H200).June had the highest average hourly ozone exceeded multiples of 0.158.The top two cities with the highest average exceeded multiple were Tangshan(0.166)and Beijing(0.158).Tangshan and Xingtai ranked as the top two in terms of the mean of the 10 highest daily maximum ozone concentrations(MTDM),with 286.74 and 285.37μg m^(−3),respectively.The gap between the MTDM and the daily maximum of hourly ozone averaged over all sites had narrowed to 97.88μg m^(−3) in 2021,much lower than that in other years,which indicated that the stability and convergence of ozone pollution in BTH region had been enhanced in 2021 to some extent.

Impacts of global biogenic isoprene emissions on surface ozone during 2000-2019

Biogenic isoprene is an important precursor of tropospheric ozone(O_(3)).Here,a coupled chemistry-vegetation model was used to quantify the contributions of isoprene emissions to surface O_(3)pollution on the global scale during 2000-2019.The biogenic isoprene emissions showed high values in mid-low latitudes and seasonal peaks in the summer hemispheres.They promote global surface O_(3)concentrations by 1.75 ppbv annually with regional hotspots of 4.39 ppbv(8.8%)in China and 5.36 ppbv(11.1%)in the U.S.in boreal summer.In the past two decades,isoprene emissions increased by 1.32 TgC yr^(−1)(0.67%yr^(−1))in the Northern Hemisphere but decreased by 0.71 TgC yr^(−1)(0.44%yr^(−1))in the Southern Hemisphere.Such changes of isoprene made opposite contributions to the surface O_(3)trend,with 0.26 ppbv yr^(−1)in eastern China but−0.32 ppbv yr^(−1)in the southeastern U.S.due to the changes in the background regime of chemical reactions.The impact of anthropogenic changes on the O_(3)trend is consistent with that of biogenic isoprene,but two to four times stronger in magnitude.This study revealed that the effective control of anthropogenic NO_(x)emissions could mitigate regional O_(3)pollution even with the increased isoprene emissions under global warming.

Implications of the extremely hot summer of 2022 on urban ozone control in China

Frequent occurrences of extreme heat are causing severe ozone pollution over China.This study examined the driving factors of urban ozone pollution in China during the extremely hot summer of 2022 and the impact of emission control strategies using surface measurements and the GEOS-Chem model.The results show that ozone pollution was extremely severe in summer 2022,with a significant rebound by 12-15 ppbv in the North China Plain(NCP),Yangtze River Delta(YRD),and Sichuan basin(SCB),compared to 2021.Especially over the NCP,the MDA8(maximum daily 8-hourly average)ozone exceeded 160 ppbv,and the number of ozone exceedances was over 42 days.Based on an IPR(integrated process rate)analysis,the authors found that the net chemical production was the dominant factor contributing to the strong ozone increase in summer 2022.For example,in June over the NCP,the net chemical production resulted in an increase by 3.08 Gg d^(−1)(∼270%)in ozone mass change.Sensitivity simulations showed that both NO_(x)(nitrogen oxides)and VOC(volatile organic compound)reductions were important over the NCP,and NO_(x)reductions were more important than VOCs over southern China.To keep the ozone of 2022 at the same level as 2021,a joint reduction of NO_(x)and VOCs by at least 50%-60%would have been required.This study highlights the urgency to develop effective ozone management since extreme heat will become more frequent.

Significant contributions of the petroleum industry to volatile organic compounds and ozone pollution:Insights from year-long observations in the Yellow River Delta

The petroleum industry is a significant source of anthropogenic volatile organic compounds(VOCs),but up to now,its exact impact on urban VOCs and ozone(O_(3))remains unclear.This study conducted year-long VOC ob-servations in Dongying,China,a petroleum industrial region.The VOCs from the petroleum industry(oil and gas volatilization and petrochemical production)were identified by employing the positive matrix factorization model,and their contribution to O_(3) formation was quantitatively evaluated using an observation-based chemical box model.The observed annual average concentration of VOCs was 68.6±63.5 ppbv,with a maximum daily av-erage of 335.3 ppbv.The petroleum industry accounted for 66.5%of total VOCs,contributing 54.9%from oil and gas evaporation and 11.6%from petrochemical production.Model results indicated that VOCs from the petroleum industry contributed to 31%of net O_(3) production,with 21.3%and 34.2%contributions to HO_(2)+NO and RO_(2)+NO pathways,respectively.The larger impact on the RO_(2) pathway is primarily due to the fact that OH+VOCs ac-count for 86.9%of the primary source of RO_(2).This study highlights the critical role of controlling VOCs from the petroleum industry in urban O_(3) pollution,especially those from previously overlooked low-reactivity alkanes.

Medical ozone alleviates acute lung injury by enhancing phagocytosis targeting NETs via AMPK/SR-A1 axis

Acute lung injury(ALI)linked to sepsis has a high mortality rate,with limited treatment options available.In recent studies,medical ozone has shown the potential to alleviate inflammation and infection.Here,we aimed to evaluate therapeutic potential of medical ozone in a mouse model of the sepsis-induced ALI by measuring behavioral assessments,lung function,and blood flow.Protein levels were quantified by Western blotting.In vitro,we performed experiments on bone marrow-derived macrophages(BMDMs)to investigate the effect of adenosine monophosphate(AMP)-activated protein kinase(AMPK)inhibitors and agonists on their phagocytic activity.The results showed that medical ozone significantly improved the survival rate,ameliorated lung injury,and enhanced lung function and limb microcirculation in mice with ALI.Notably,medical ozone inhibited the formation of neutrophil extracellular traps(NETs),a crucial factor in the ALI development.Additionally,medical ozone counteracted the elevated levels of tissue factor,matrix metalloproteinase-9,and interleukin-1β.In the ALI mice,the effects of ozone were abolished,and BMDMs showed an impaired capacity to engulf NETs following the Sr-a1 knockout.Under normal physiological conditions,the administration of an AMPK antagonist showed similar effects on the Sr-a1 knockout,significantly inhibiting the phagocytosis of NETs by BMDMs.In contrast,AMPK agonists enhanced this phagocytic process.In conclusion,medical ozone may alleviate the sepsis-induced lung injury through the AMPK/SR-A1 pathway,thereby enhancing the phagocytosis of NETs by macrophages.

Implications of 1.5 K climate warming on warm-season ozone exposure and atmospheric oxidation capacity in China

Surface ozone(O_(3))poses significant threats to public health,agricultural crops,and plants in natural ecosystems.Global warming is likely to increase future O_(3)mainly by altering atmospheric photochemical reactions and enhancing biogenic volatile organic compound(BVOC)emissions.To assess the impacts of the future 1.5 K climate target on O_(3)concentrations and ecological O_(3)exposure in China,numerical simulations were conducted using the CMAQ(Community Multiscale Air Quality)model during April-October 2018.Ecological O_(3)exposure was estimated using six indices(i.e.,M7,M24,N100,SUM60,W126,and AOT40f).The results show that the temperature rise increases the MDA8 O_(3)(maximum daily eight-hour average O_(3))concentrations by∼3 ppb and the number of O_(3)exceedance days by 10-20 days in the North China Plain(NCP),Yangtze River Delta(YRD),and Sichuan Basin(SCB)regions.All O_(3)exposure indices show substantial increases.M24 and M7 in eastern and southern China will rise by 1-3 ppb and 2-4 ppb,respectively.N100 increases by more than 120 h in the surrounding regions of Beijing.SUM60 increases by greater than 9 ppm h^(−1),W126 increases by greater than 15 ppm h^(−1)in Shaanxi and SCB,and AOT40f increases by 6 ppm h^(−1)in NCP and SCB.The temperature increase also promotes atmospheric oxidation capacity(AOC)levels,with the higher AOC contributed by OH radicals in southern China but by NO_(3)radicals in northern China.The change in the reaction rate caused by the temperature increase has a greater influence on O_(3)exposure and AOC than the change in BVOC emissions.

Effects of Chlorine and Chlorine Monoxide on Stratospheric Ozone Depletion

This paper presents a system approach of mass balance calculations of ozone and other species under diffusion-convection-reaction processes to study the impacts of major ozone-depleting chemicals, chlorine (Cl) and chlorine monoxide (ClO), and the effect of photolysis on ozone concentrations, ozone depletion, total ozone abundance, and ozone layer along the altitude in the stratosphere. The calculated ozone concentrations and profile of the layer followed a similar trend and were generally in good agreement with the measurements above the tropical area. The calculated peak of the layer was at the same mid-stratosphere at Z = 30 km with a peak concentration and total ozone abundance about 20% higher than the measured peak concentration of 8.0 ppm and total abundance of 399 DU. In the presence of Cl and ClO, the calculated ozone concentrations and total abundance were substantially reduced. Cl generally depleted more uniformly of ozone across the altitude, while ClO reduced substantially the ozone in the upper stratosphere and thus shifted the peak of the layer to a much lower elevation at Z = 14 km. Although both ClO and Cl are active ozone-depleting chemicals, ClO was found to have a more pronounced impact on ozone depletion and distribution than Cl. The possible explanations of these interesting phenomena were discussed and elaborated. The approach and calculations in this paper were shown to be useful in providing an initial insight into the structure and behavior of the complex ozone layer.

Study on the spatial and temporal evolutionary characteristics of ozone concentration and the impact of human activities in China in 2019

Ozone(O_(3))pollution has a profound impact on human health,vegetation development,and the ecological environment,making it a critical focus of global academic research.In recent years,O_(3)pollution in China has been on a steady rise,with ozone emerging as the sole conventional pollutant to consistently increase in concentration without any decline.This study conducted a quantitative analysis of O_(3)concentrations across 367 Chinese cities in 2019,examining spatial autocorrelation and local clustering of O_(3)levels,and investigated the diverse relationships between human activity factors and O_(3)concentration.The seasonal fluctuation of O_(3)exhibited the“M-type”pattern,with peak concentrations in winter and the lowest levels in summer.The center of O_(3)pollution migrated southeastward,with the area of highest concentration progressively shifting south along the eastern coast.Moreover,O_(3)concentration showed a strong positive correlation with population density,road freight volume,and industrial emissions,suggesting that human activities,vehicle emissions,and industrial operations are significant contributors to O_(3)production.The results provide comprehensive information on the characteristics,causes,and occurrence mechanism of O_(3)in Chinese cities that can be utilized by global government departments to formulate strategies to prevent and control O_(3)pollution.

Surface ozone in global cities:A synthesis of basic features,exposure risk,and leading meteorological driving factors

Long-term exposure to high surface ozone(O_(3))concentrations,a complex oxidative atmospheric pollutant,can adversely impact human health.Based on O_(3)monitoring data from 261 cities worldwide in 2020,generalized additive model(GAM)and spatial data analysis(SDA)methods were applied in this study to quantitatively evaluate the spatiotemporal distribution of O_(3)concentration,exposure risk,and dominant meteorological factors.Results indicated that over 40%of the cities worldwide were exposed to harmful O_(3)concentration ranges(40-60μg/m^(3)),with most cities distributed in China and India.Moreover,significant seasonal variations in global O_(3)concentrations were observed,presenting as summer(45.6μg/m^(3))>spring(47.3μg/m^(3))>autumn(38.0μg/m^(3))>winter(33.6μg/m^(3)).Exposure analysis revealed that approximately 12.2%of the population in 261 cities were exposed to an environment with high O_(3)concentrations(80-160μg/m^(3)),with about 36.32 million people in major countries.Thus,the persistent increase in high O_(3)levels worldwide is a critical factor contributing to threats to human health.Furthermore,GAM results indicated temperature,relative humidity,and wind speed as primary determinants of O_(3)variability.The synergy of meteorological factors is critical for understanding O_(3)changes.Our findings are important for enforcing robust air quality policies and mitigating public risk.

Calculations and Sensitivity Analysis of Chlorine-,NO_(x)-,and Bromine-Depleting Cycles of Stratospheric Ozone

This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the stratosphere.By considering all fourteen photolysis,ozone-generating,and-depleting chemical reactions,the model calculated the transient,spatial changes of ozone under different physical-chemical-radiative conditions.Validation against the measured data demonstrated good accuracy,close match of our model with the observed ozone concentrations at both 20°S and 90°N locations.The deviation in the average concentration was less than 1% and in ozone profiles less than 17%.The impacts of various chlorine-(Cl),nitrogen oxides-(NO_(x)),and bromine-(Br)depleting cycles on ozone concentrations and distribution were investigated.The chlorine catalytic depleting cycle was found to exhibit the most significant impact on ozone dynamics,confirming the key role of chlorine in the problem of ozone depletion.Sensitivity analysis was conducted with levels of 25%,50%,100%,200%,and 400% of the baseline value.The combined cycles(Cl+NO_(x)+Br)showed the most significant influence on ozone behavior.The total ozone abundance above the South Pole could decrease by a small 3%,from 281 DU(Dubson Units)to 273 DU for the 25% level,or by a huge thinning of 60%to 114 DU for the 400% concentration level.When the level of chlorine gases increased beyond 200%,it would cause ozone depletion to a level of ozone hole(below 220 DU).The 2D Ozone Model presented in this paper demonstrates robustness,convenience,efficiency,and executability for analyzing complex ozone phenomena in the stratosphere.

Effect of Ozone Treatment on Microbiological Properties of Stored Wheat

In this study, ozone gas was applied to samples of durum wheat stored in four experimental groups (durum wheat without any treatment for comparison, durum wheat treated with ozone, purified durum wheat, and purified durum wheat treated with ozone). Two groups were treated with ozone gas at 3 ppm concentration for 1 hour. Groups were then placed in air-tight glass jars and stored for 6 months at variable temperatures between 24.7°C to 34.8°C. Microbiological (total count bacteria, yeast/molds and coliform) and physical properties (moisture, color and ash) evaluated. Ozone application statistically caused a significant reduction in the numbers of bacteria, yeast, molds and coliforms. Ozone application, washing process and storage temperature are the major factors affecting the microbial counts. No significant differences were determined in moisture and ash contents of samples after ozone treatment. The color measurement results showed that color values of wheat samples were affected by ozone treatment, storage and washing.

Ozone Sterilizer for Treatment and Health Care

Ozone is a green broad-spectrum bactericidal disinfectant, and a trace amount of ozone in the atmosphere makes many viruses and bacteria lose their biochemical activity and infectivity. Nature produces trace amounts of ozone in the air through lightning to purify the ecological environment. The product of ozone decomposition is oxygen, without secondary pollution. Ozone sterilizer is widely used in the epidemic prevention and control of intensive breeding farms and achieved remarkable results. If the concentration and action time of ozone can be accurately controlled, then ozone can quickly eliminate pathogens, without harming the normal cells in the human body. How to use medical ozone for epidemic prevention, treatment and health care is a subject worthy of serious study, which should arouse the attention of the experts in the field.

Forecast Method of Ozone Concentration in Yulin City Based on Meteorological Conditions

Based on the monitoring data of ozone(O 3)concentration,conventional meteorological data and reanalysis products in Yulin City from 2018 to 2019,the weather situation of O 3 pollution was classified through case analysis and mathematical statistics.At 500 hPa,the weather situation was divided into continental high pressure type,subtropical high type and mixed type.At 850 hPa,it was divided into southwest air flow type,east air flow type and south air flow type.The correlation between meteorological element and O 3 concentration were analyzed,and factors with good correlation such as temperature,air pressure and wind speed were selected to establish regression equations.The fitting effect was good,and O 3 concentration could be objectively predicted.

2-D Modeling and Calculations of Stratospheric Ozone and Influences of Convection, Diffusion, and Time

An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical reaction equations was developed, validated, and used for studying the ozone concentrations, distribution and peak of the layer, ozone depletion and total ozone abundance in the stratosphere. The calculated ozone concentrations and profile at both the Equator and a 60˚N location were found to follow closely with the measured data. The calculated average ozone concentration was within 1% of the measured average, and the deviation of ozone profiles was within 14%. The monthly evolution of stratospheric ozone concentrations and distribution above the Equator was studied with results discussed in details. The influences of slow air movement in both altitudinal and radial directions on ozone concentrations and profile in the stratosphere were explored and discussed. Parametric studies of the influences of gas diffusivities of ozone DO3 and active atomic oxygen DO on ozone concentrations and distributions were also studied and delineated. Having both influences through physical diffusion and chemical reactions, the diffusivity (and diffusion) of atomic oxygen DO was found to be more sensitive and important than that of ozone DO3 on ozone concentrations and distribution. The 2-D ozone model present in this paper for stratospheric ozone and its layer and depletion is shown to be robust, convenient, efficient, and executable for analyzing the complex ozone phenomena in the stratosphere. .

Preserving the Ozone Layers: Battling Illegal Trade in Ozone-Depleting Substances

The depletion of the ozone layer, a vital shield protecting the Earth from harmful ultraviolet (UV) radiation, is now a worldwide environmental concern. Human activities, particularly the release of ozone depleting substances (ODS), have led to the thinning of this protective layer over recent decades. Simultaneously, illegal trade has emerged as a global challenge, giving rise to economic issues, losses of tax revenue, heightened criminal activities, health risks, and environmental hazards. The depletion of the ozone layer, a critical shield protecting the Earth from harmful ultraviolet (UV) radiation, has become a global environmental concern. This paper delves into the legal dimensions surrounding ozone-depleting substances (ODS), their impact on the ozone layer, and the subsequent risk of skin cancer. As countries navigate international agreements, domestic regulations, and enforcement mechanisms, the intricate interplay between legal frameworks and the health implications of ozone layer depletion comes to the forefront. The paper highlights particular instances of illegal trade in ozone depleting substances, drawing from data reported by the parties to the Montreal Protocol. Notably, China stands out as a significant source of contraband ODS, with other countries such as Bulgaria, Lithuania, Poland, and France reporting numerous cases. Analyzing these case instances offers insights into the efficacy of legal frameworks and enforcement measures. The paper offers a comprehensive set of recommendations to strengthen global control and enforcement against the illegal trade of ozone depleting substances. These recommendations span diverse aspects such as production monitoring, customs collaboration, mutual verification, cross-border agreements, public-private partnerships, international cooperation, detection equipment, global regulatory standards, resource allocation, public awareness campaigns, alternative substance development, and controlling the trade at its source. By applying these recommendations and enhancing enforcement measures, we aim to protect the ozone layer and create a healthier and safer world for future generations and achieve sustainable development goals.

Characteristics of Ozone Variations in Lhasa in Recent Years

The variation characteristics of ozone in Lhasa in recent years were analyzed by using Brewer spectrometer observation data. The results showed that ozone was mainly distributed in 15-35 km in atmosphere in Lhasa; the peak value by inversion was in 21-25 km; by comparison of ozone vertical distribution in Lhasa, it can be concluded that ozone differs insignificantly in middle-to-high layers in stratosphere and the distribution is similar over 36 km. The difference can be observed from the fact that ozone concentration is higher in winter and spring compared with summer and autumn from ground to the height at 21 km. In recent 4 years, annual average of total ozone in Lhasa was of little variations and extreme values of ozone appeared in winter and spring. Monthly averages were lower in August and September, and the lower value of ozone kept longer in 2008 for 23 d.

基于Ozone算法的GPS大地坐标变换

基于Ozone算法的GPS大地坐标变换,采用WGS-84地心坐标系。其基本参数包括椭球体长/短半轴和体扁率、地球引力常数及自转角速度等。该算法无需迭代,即可由大地直角坐标直接求出地理坐标。其算例只考虑经纬度二维情况可满足精度要求,并提高数据处理效率。

Promotional effect of spherical alumina loading with manganese-based bimetallic oxides on nitric-oxide deep oxidation by ozone

Nitric oxide （NO） deep oxidation to dinitrogen pentoxide （N2O5） by ozone together with wet scrub-bing has become a promising technology for nitrogen-oxide （NOx） removal in industrial boilers. Catalysts were introduced to enhance the N2O5 formation rate with less ozone injection and leakage. A series of monometallic catalysts （manganese, cobalt, cerium, iron, copper, and chromium） as pre-pared by the sol-gel method were tested. The manganese oxides achieved an almost 80% conver-sion efficiency at an ozone （O3）/NO molar ratio of 2.0 in 0.12 s. The crystalline structure and porous parameters were determined. The thermodynamic reaction threshold of NO conversion to N2O5 is oxidation with an O3/NO molar ratio of 1.5. Spherical alumina was selected as the support to achieve the threshold, which was believed to improve the catalytic activity by increasing the surface area and the gas-solid contact time. Based on the manganese oxides, cerium, iron, chromium, cop-per, and cobalt were introduced as promoters. Cerium and iron improved the deep-oxidation effi-ciency compared with manganese/spherical alumina, with less than 50 mg/m3 of outlet NO ＋ nitro-gen oxide, and less than 25 mg/m3 of residual ozone at an O3/NO molar ratio of 1.5. The other three metal oxides inhibited catalytic activity. X-ray diffraction, nitrogen adsorption, hydrogen tempera-ture-programmed reduction, and X-ray photoelectron spectroscopy results indicate that the cata-lytic activity is affected by the synergistic action of NOx oxidation and ozone decomposition.

Treatment of Landfill Leachate by Stripping and Catalytic Ozone Oxidation

In order to investigate the effect of stripping and catalytic ozone oxidation technology on COD and ammonia nitrogen removal after coagulation and sedimentation, the efficiency of ozone oxidation and catalytic ozone oxidation were compared. The experimental results showed that： stripping and catalytic ozone oxidation technology has a significant effect on landfill leachate treatment. The removal rate of the COD and NH3-N can reach 88.60% and 98.00% under the initial concentration of COD and NH3-N were 2053.35 mg/L and l 123. 76 mg/L separately.

Effects of Ozone Stress on Physiological and Biochemical Characteristics Dwarfing Rootstock M9T337

[Objective] To investigate the effects of different ozone concentrations （30, 60, 80, 100 and 120 μg/L） on the physiological and biochemical characteristics of M9T337, so as to provide theoretical basis for breeding anti-ozone dwarfing root- stocks. [Method] The effects of different concentrations of ozone on chlorophyll con- tent, antioxidant enzyme activity, malondialdehyde （MDA） and soluble protein content of M9T337 were studied by potting dwarfing rootstock M9T337 as test material. [Result] With the increase of ozone concentration, the content of chlorophyll in M9T337 leaves decreased gradually. The activity of SOD （superoxide dismutase） and CAT （catalase） increased first and then decreased, while POD （Peroxidase） ac- tivity and MDA （malondialdehyde） content were gradually increased. [Conclusion] The comprehensive analysis of the indicators indicated that the potted M9T337 could tolerate the low concentration （〈80 μg/L） ozone stress in the short time （〈3 h）, and it would cause serious injury to M9T337 when the ozone concentration ex- ceeded 80 μg/L.