南京市硫酸盐化速率地方标准的制定

研究ＳＯ＿２与硫酸盐化速率的相关关系，以ＧＢ３０９５－８２（大气环境质量标准）中的ＳＯ２标准为基础，并借鉴国外先进国家的标准和硫酸盐化速率植物试验的成果，结合南京市大气环境质量现状，制定适合于南京地区的大气硫酸盐化速率建议标准．     

沈阳市冬季环境空气质量统计预报模型建立及应用

利用沈阳市2013年1—2月大气自动监测数据和同期气象资料,选取19项预报因子,采用逐步回归方法建立了沈阳市冬季环境空气质量统计预报模型,预报项目包括细颗粒物(PM2.5)、可吸入颗粒物(PM10)、二氧化硫(SO2)、二氧化氮(NO2)、一氧化碳(CO)日均浓度及臭氧(O3)日最大8 h平均浓度。2013年11月至2014年1月,应用该模型并结合人为经验修订,开展了沈阳市环境空气质量预报工作,预报结果与实测结果的对比验证结果表明,环境空气预测结果级别准确率达到79.1%,首要污染物准确率为73.6%。     

Vertical ozone distributions observed using tethered ozonesondes in a coastal industrial city, Kaohsiung, in southern Taiwan

This work presents the vertical distributions of ozone and meteorological parameters observed with tethered ozonesondes and meteorological radiosondes in the lower atmosphere during an ozone episode on March 25–27, 2003, in Kaohsiung City in southern Taiwan. Kaohsiung is a coastal industrial city with inland mountain ranges to the east. Extremely complicated ozone structures were identified that spanned day and night during the experimental period. During afternoons, the lower atmosphere was divided into two stratified air layers with substantially different ozone concentrations. On the episode day (March 26), average ozone concentration in the near-ground layer was 85 ppb and the aloft layer was 140 ppb. A very high ozone peak of 199 ppb measured aloft likely resulted from an elevated large point source. Several no-ozone air layers, distributed throughout 400–750 m, were observed to transport onshore during the nigh. As well, elevated ozone layers peaking at 60–90 ppb and 90–160 ppb were detected below and above the no-ozone air layers, respectively. These complicated ozone structures were likely formed through titration of plumes from large point sources and the circulations of sea breezes or combined sea-breeze/mountain flows in the study area.     

Monitoring of Particle Mass and Number in Urban Air

Measurements of aerosol particles in the air of an urban area in the UK have been made. Ambient air was sampled and the particulates measured after passing through a size selective PM₁₀ inlet. Particle mass was measured using a Tapered Element Oscillating Microbalance (TEOM). Particle number and size distributions were obtained using an Electrical Aerosol Analyser (EAA) and an Aerodynamic Particle Sizer (APS). Measurements were also made of local meteorological parameters. Fine particle number concentrations were found to show better temporal agreement, including diurnal variation, with particle mass concentrations than the coarser particle number concentrations.     

A Simple Model for Urban Background Pollution

A simple urban background pollution model is presented. Contributions from the individual area sources, subdivided into a grid net of a resolution of 2km × 2km, are integrated along the wind direction path assuming linear dispersion with the distance to the receptor point. Horizontal dispersion is accounted for by averaging the calculated concentrations over a certain, wind speed dependent wind direction sector, centred on the average wind direction. Formation of the nitrogen dioxide due to oxidation of nitrogen monoxide by ozone is calculated using a simple chemical model based on assumption of a photochemical equilibrium on the time scale of the pollution transport across the city area. The rate of entrainment of fresh rural ozone is governed by this time scale. The model is suitable for calculations of urban background when the dominating source is the road traffic. For this source the emissions take place at ground level, and a good approximation is to treat the emissions as area sources, but with an initial vertical dispersion determined by the height of the buildings.     

沈阳臭氧污染时空分布特征及变化趋势

以沈阳2013—2015年臭氧(O_3)监测数据为基础,从地域差异及时间变化上分析了沈阳O_3浓度变化特征。结果表明:沈阳城市外围O_3浓度高于城市中心;O_3浓度变化具有明显季节特征,夏季O_3浓度最高,冬季最低;O_3浓度日变化呈单峰分布,谷值出现在06:00,峰值出现在14:00;O_3浓度出现明显"周末效应",周末白天O_3浓度高于工作日O_3浓度,夜间差异不大。     

应用稳健统计方法对环境空气臭氧自动监测现场比对核查结果的分析研究

根据2015年9个城市53台现场臭氧分析仪的现场比对核查结果,比较研究了稳健统计方法和一般统计方法在评价国控网臭氧自动监测数据准确性和精密性上的应用。研究表明:稳健统计能够在不剔除异常数据的前提下降低异常值对正确评价臭氧自动监测数据质量的影响,适合评价现场比对核查结果;采用Hubers方法进行稳健统计,2015年国控网臭氧日常浓度点相对偏差的95%置信区间约为-0.1%至4.5%,95%预测区间为-14.0%~18.3%,变异系数约为9.5%,数据质量仍有提升空间。     

Variation of Surface Ozone in the Ambient Air of Auckland, New Zealand

A study has been performed on the characteristics and behavior of surface ozone concentrations at four monitoring sites in Auckland, New Zealand (37 degrees S, 174.8 degrees E) for a four-year period (October 1997-October 2001). One monitoring site (rural) was located upwind of the Auckland urban complex, a second downwind (rural-coastal), and a third within the urban area, while the fourth was an elevated urban-city site located 250 m up the Sky Tower in the central city. In contrast to the high elevation site, the diurnal behaviour of ozone at the three low elevation sites followed a typical solar radiation cycle with high ozone during the day and low nocturnal values. The effect of NO(x) titration was distinct at the urban sites. There was also a seasonal variability in the measured ozone levels with high concentrations in spring and a significant summer minimum. The observed surface ozone concentrations in Auckland were significantly lower than other cities of the world, although a potential for high oxidant formation existed. Observed ozone episodes appear to have been either generated locally or the precursors transported via the prevailing southwest wind. A unique feature of Auckland's air quality is the dilution of polluted city air due to the mixing of east-coast air into the clean west-coast circulation leading to the overall lower average concentrations in summer. A second feature is the potential interaction between sea salt particles and ozone that may provide an additional ozone loss mechanism.     

Measuring reactive nitrogen emissions from point sources using visible spectroscopy from aircraft

Accurate measurements of nitrogen dioxide (NO2), a key trace gas in the formation and destruction of tropospheric ozone, are important in studies of urban pollution. Nitrogen dioxide column abundances were measured during the Texas Air Quality Study 2000 using visible absorption spectroscopy from an aircraft. The method allows for quantification of the integrated total number of nitrogen dioxide molecules in the polluted atmosphere and is hence a useful tool for measuring plumes of this key trace gas. Further, we show how such remote-sensing observations can be used to obtain information on the fluxes of nitrogen dioxide into the atmosphere with unique flexibility in terms of aircraft altitude, and the height and extent of mixing of the boundary layer. Observations of nitrogen dioxide plumes downwind of power plants were used to estimate the flux of nitrogen oxide emitted from several power plants in the Houston and Dallas metropolitan areas and in North Carolina. Measurements taken over the city of Houston were also employed to infer the total flux from the city as a whole.     

气象条件对沈阳市环境空气臭氧浓度影响研究

利用2013年沈阳市环境空气监测点位臭氧监测数据,分析沈阳臭氧浓度变化特征,结合气象资料分析了其对臭氧浓度的影响。结果表明,沈阳市不同区域臭氧浓度变化特征基本一致。臭氧浓度日变化呈单峰趋势,最大值出现在14:00左右,最小值出现在6:00左右;臭氧浓度变化具有明显的季节特征,夏季臭氧浓度最高,春秋次之,冬季最低;臭氧浓度受温度、风速、湿度、能见度、天气情况影响,臭氧浓度变化是多因素共同作用的结果。     

A study of ground-level ozone pollution, ozone precursors and subtropical meteorological conditions in central Taiwan

Hourly concentrations of ozone (O(3)), 55 volatile organic compounds (VOCs, ozone precursors) and nitrogen oxides (NOx) were measured at an upwind urban site, a downwind suburban site, and a rural site in central Taiwan, from January 2003 to December 2006. VOC and NOx mean concentrations showed a gradient from high to low across the urban (56 ppb and 34 ppb), suburban (38 ppb and 27 ppb) and rural sites (25 ppb and 21 ppb) but a reverse gradient in ozone across these sites (24, 27, and 29 ppb, respectively). Although there was about twice the difference in VOC concentrations between the urban and rural sites, nearly 65% ozone formation potential was contributed to by the same 9 VOCs. Seasonal patterns showed peak ozone levels in autumn and minima in summer at the urban site, but minima in winter at the downwind suburban and rural sites. Ozone precursor levels, on the other hand, were lowest in summer and highest in winter. The diurnal pattern showed that ozone levels peaked one hour later at the rural site than at the urban site. The ethylbenzene to m,p-xylene ratio, an indicator of the age of the air mass, increased from 0.4 at the urban site to 0.6 at the suburban site and 0.8 at the rural site during daily peak ozone times. This finding suggests the transport of ozone and precursors from upwind to downwind producing elevated ozone levels in the suburban and rural areas. Ozone episodes occurred mostly in days with a mean midday UV index of 6.5 (1 UV index=100 J m(-2)) and wind speed at 1.3 m s(-1) at all three sites.     

衡阳市区和衡山背景站臭氧浓度变化规律的对比分析

选取衡阳市区和衡山背景站臭氧自动监测数据,分析两地的臭氧污染特征。对空气质量的优良率情况、臭氧作为首要污染物的变化情况、臭氧浓度的日变化特征、典型时段的浓度变化特征、臭氧浓度的月际变化特征和臭氧与PM_(2.5)的关联情况等进行了分析。结果表明,多云及阴雨天气时,衡阳市区的臭氧浓度日变化幅度大于衡山背景站。夏季,衡阳市区和衡山背景站的臭氧浓度的日变化特征规律差异较大,臭氧浓度分布比较分散,前者为典型的单峰形,后者则波动平缓。冬季,日变化幅度不大,但衡阳市区的臭氧浓度明显低于衡山背景站。衡山背景站和衡阳市区的臭氧基本同步变化,但日均值高于衡阳市区。     

湖北臭氧分布特征及其管控措施

采用地面站点观测、卫星观测以及UWCM 0-D箱子模型模拟的方法研究湖北2013—2015年臭氧时空分布特征,并探讨其管控措施。从地面站点观测看出,时间分布上,这3年臭氧年平均浓度经历先下降后上升的过程,总体呈上升趋势,而二氧化氮年平均浓度则呈现持续下降的趋势;空间分布上,湖北各区域臭氧浓度分布不均匀,呈现东高西低的递减分布趋势。从卫星观测数据看出,2015年湖北的臭氧柱浓度高于2013、2014年同期。从空间分布来看,臭氧的柱浓度是从东北到西南、从省外到省内逐渐递减,因此推测,除了本地生成,湖北的臭氧有一部分是来源于省外传输。最大臭氧生成量法显示,烯烃(乙烯和丙烯)对湖北夏天臭氧生成量的贡献远大于其他挥发性有机化合物。箱子模型模拟的结果显示,湖北应该通过控制挥发性有机化合物的排放来降低臭氧生成速率,控制氮氧化物反而使臭氧生成速率提高。     

Analysis of Long-term Measurements of Airborne Concentrations of Sulphur Dioxide and SO42- in the Rural United Kingdom

During the last two decades, the importance of sulphur dioxide as a pollutant has moved away from its association with suspended particulate matter, to it being a precursor of SO ₄ ^2- aerosol (acidic e.g. sulphuric acid, or neutralised e.g. ammonium sulphate). Co-located concentration data of sulphur dioxide and SO ₄ ^2- , at nine monitoring sites situated in predominantly rural areas in the United Kingdom, collected over the time period 1979–1995, have been analysed. The time series for both species are discussed for the sites. Further analysis has shown that there is a degree of correlation between sulphur dioxide and SO ₄ ^2- for most of the sites considered. This correlation is of approximately the same level for most of the sites taken independently and together, and in most cases the slopes and intercepts associated with the simple empirical model equations arising from the correlation analysis, are of the same order of magnitude. The implementation of these site-dependent model equations within dispersion models for the prediction of the concentration of airborne sulphate aerosol from knowledge of sulphur dioxide concentration is discussed. Furthermore, the correlation analysis revealed the influence of transported sulphate aerosol on the local concentration, especially during high concentration episodes.     

Exposure estimates for the Houston Area Asthma Study

Procedures for determining exposure extimates for the Houston Area Asthma Study are discussed. Two residential clusters of asthmatics in the Houston area have been studied as part of an overall attempt to assess the health effects of air pollution in the Texas Gulf Coast area. Air pollutant exposure data have been produced according to a three-tier monitoring scheme, i.e. (1) continuous data from centrally-located fixed stations, (2) residential indoor/outdoor measurements, and (3) personal monitoring. This air monitoring network should yield estimates of individual exposures for use in health effect correlations.The fixed sites and mobile continuously monitor ambient levels of ozone, nitrogen oxides, sulfur dioxide, carbon monoxide, and meteorological parameters (wind speed, wind direction, temperature, dew point, solar irradiation, and precipitation). Continuous sequential integrated sampling is preformed for total suspended particulates (TSP) and, inhalable particulates (IP) (total of < 2.5m and 2.5–15.0 m) by dichotomous samplers for 24 hr samplers), aldehydes (bubblers), and aeroallergens (intermittent rotorod samplers). In addition to gravimetric determinations, particulate filters are routinely analyzed for sulfate, nitrate, and (every third day) trace elements. Personal monitoring includes ozone, respirable particles, nitrogen dioxide and formaldehyde. A quality assurance/control program that meets specifications established in the EPA Quality Assurance Handbook for air pollution measurement systems was implemented. Examples of results consisting of unvalidated preliminary data from the monitoring for ozone for three participants is presented and approaches to determining exposure estimates are discussed for both an integrated exposure estimate and short time period exposure estimate.(These studies have been funded by the U.S. Environmental Protection Agency through Cooperative Agreement CR 807108010 and Grant R 808738010. Statements made in this article should not be taken as Agency policy.)     

Assessment of ozone effects on local rice cultivar by portable ozone fumigation system in Hanoi, Vietnam

This study examined the effects of troposphere ozone (O3) on rice by developing a portable ozone fumigation system and applied to the field in Hanoi, Vietnam. The system was nearly identical to the open top chamber but designed to easily and cheaply assess the O3 sensitivity of local agricultural crops in the actual field. The rice (Oryza sativa L.) was exposed to ozone during the flowering stage at peri-urban experimental site of Hanoi. The fumigation protocols covered five different levels, namely; non-filtered air (ambient) as the control treatment, 32, 62, 85 and 113 ppb in 7-h mean. It was found that observed impacts corresponded well to similar open-top chamber studies in other Asian countries. The methodology and the system left a large room for improvement and called for very careful interpretation and pre-conditions (e.g. low ambient O3 concentration). However, the portable O3 exposure in the field might open a door to the less developed countries to implement the phytotoxic risk assessment of the local agricultural species.     

Dependence of Ozone Biomonitoring on Meteorological Conditions of Different Sites in Catalonia (N.E. Spain)

Evaluation of visual symptoms of ozone damage was conducted in the network of bioindicator rural stations of Catalonia (NE Spain) every 14 days from May to October. Damage rates of ozone (and consequently, ozone biomonitoring capacity of bioindicators) were found to vary highly in time and space depending on the local environmental and meteorological conditions. Lower ozone damage to foliage was produced when meteorological conditions favour stomata resistance. Modulatory effects of meteorological conditions need to be considered in biomonitoring and when modeling plant ozone doses and damage.     

Seasonal variation in the acute effects of ozone on premature mortality among elderly Japanese

We conducted a multicity time-series study using monitoring data to assess seasonal patterns of short-term ozone–mortality association among elderly aged 65 years and over in Japan. Daily exposure to ambient ozone was computed using hourly measurements of photochemical oxidants available at multiple monitoring stations in each city. Effects of ozone on daily all-cause non-accidental, cardiovascular, and respiratory mortality were estimated using distributed lag linear models, controlling for confounding by temporal, day of the week, temperature, and flu epidemics. City-level effect estimates were combined using inverse variance meta-analysis. In spring and autumn, a 10-ppbv increase of daily maximum 8-h average ozone concentration in the previous 3 days was associated with 0.69 % (95 % confidence interval (CI): 0.27–1.10), 1.07 % (0.34–1.82), and 1.77 % (0.78–2.77) increases in daily all-cause, cardiovascular, and respiratory mortality, respectively. Forward displacement of respiratory mortality was large during the cold season despite lower ozone concentration. Results were generally independent of fine particulate matter and nitrogen dioxide. Findings suggest significant mortality effects of short-term ozone exposure among the elderly during the moderate season. Those with underlying respiratory diseases were susceptible, even during winter.     

跨漂时间对空气自动监测站二氧化硫准确度的影响

利用国家环保部标准样品研究所已知标准气体,选取绵阳市的三个城市空气自动监测站进行二氧化硫实验分析。结果表明,EC9850B二氧化硫监测仪跨漂后仪器响应快速升至最高值然后逐渐升高趋向稳定,通过连续跨漂的监测数据与已知标准气体的符合性确定仪器跨漂35min后基本稳定,并在标准气体中值附近波动,据此开始记录数据,准确度高,数据有效且质量可控。     

Measurements of Ozone Concentrations in Zagreb

Ozone concentrations were measured in Zagreb at four sites from May 1999 to April 2001 in order to categorize the air quality with respect to ozone. In the summer of 2000, the ozone measurements were also extended to four sites in the suburbs of Zagreb. Methods of active and passive sampling with nitrite ion as a reagent were used. In the northern part of the town ozone was analyzed by an automatic device. Automatic device measurements in the years 1999 and 2000 showed that hourly averages of ozone concentrations did not exceed the Croatian recommended value of the 98th percentile (180 g m^–3). Over the two-year period, 24-h averages occasionally exceed 110 g m^–3 in city center and in the northern part of the town. Regardless of these isolated examples, ozone was well within acceptable concentrations. Ozone concentrations measured in summer 2000 were higher in the suburbs of Zagreb than in the city. The 98th percentile values higher than 110 g m^–3 were recorded at three sites.