小气候对临汾市空气污染的影响机制探讨

通过研究临汾市的地形结构、气候特点,本文得出该地区小气候主要为山谷风、地形逆温和城市热岛。系统分析这些小气候的成因及特点,初步探讨小气候对临汾市空气污染的影响机制。研究显示:三种小气候均在不同程度上加剧了临汾市空气污染的广度和深度。其中山谷风加剧了临汾市区、矿区和郊区的空气污染重叠,使污染物不停地聚集到上层大气,造成多次污染;地形逆温则阻碍了空气的垂直对流运动,妨碍了烟尘、污染物、水汽凝结物的扩散;热岛环流产生堆积效应,使得郊区产生的污染通过环流进一步影响城市。此外,本文给出了改善城市小气候的若干建议。     

主成份分析研究天津市硫酸盐等空气污染

用主成份分析法研究了天津市1980年秋冬两季空气中硫酸盐等的污染,共分析342个样本,每个样本包括17个变量。发现天津市严重的硫酸盐空气污染出现在冬天早晨小风、静风时,总颗粒物、二氧化硫、氮氧化物等在城市下风方向聚积起来的空气污染烟幕中。识别出四个空气污染主要大气物理化学过程,各过程及其对硫酸盐变化的贡献率分别为:聚积过程57.9％、非甲烷烃6.5％、季节变化5.0％、相对湿度3.7％.推测一次排放和/或二氧化硫在颗粒物表面上的非均相似化氧化过程是天津市形成硫酸盐空气污染的主要过程。推算出二氧化硫转化成硫酸盐的表观一级转化速率为6.2±2.0％小时~(-1)或9.3±2.2％小时~(-1),视二氧化硫沉降速率的取值。     

城市森林生态系统滞纳空气颗粒物功能向生态系统服务的转化率

生态系统服务是生态系统功能中有利于人类福祉的部分,生态系统功能向服务的转化研究成为未来生态系统服务评估的重要发展方向.以大气环境污染较为严重的北京市和陕西省关中地区的城市森林生态系统为例,利用气溶胶再形成法,研究不同树种和污染区城市森林生态系统滞纳空气颗粒物能力,探讨其向服务的转化率问题.结果表明,城市森林生态系统中不同树种滞纳空气颗粒物功能向服务的转化率存在差异,雪松最高,达95%,而白皮松最低,仅为47%,树种滞纳颗粒物能力与转化率没有必然联系,电镜扫描结果显示与叶表微观结构特征如气孔大小或多少、绒毛长短、蜡质层有无等有关.空气污染强度不同的多个城市中,转化率为宝鸡西安咸阳韩城杨凌渭南铜川,空气污染严重的城市转化率较高,空气质量优越且颗粒物含量少的城市,转化率相对较低.因此,叶片表面结构和树种所处地区的空气污染程度共同决定了城市森林生态系统滞纳空气颗粒物功能向服务的转化率;空气质量较差地区应增加绿地面积、提高植被覆盖率,有针对性地选择转化率较高的树种.     

天空蓝色饱和程度与城市空气质量等级的相关性

以大气散射理论为基础,结合颜色学、大气环境监测及城市空气质量日报等相关原理,从理论分析与实证研究2个方面证实了天空蓝色饱和程度与城市空气质量等级之间存在着显著的负相关性,即:天空蓝色饱和程度越低,空气污染等级越高,空气质量状况越差;天空蓝色饱和程度越高,空气污染等级较低,空气质量状况越好;通过相关及回归分析与检验,制得“城市空气质量等级目测色卡”,适用于晴朗天气肉眼观察天空颜色,进而目测估计空气质量等级状况,以采取必要防护措施。     

表观遗传学机制与空气污染的健康效应

空气污染是一个全球性的问题,并且具有深远的环境影响。暴露于空气污染会对人体健康产生许多不同的影响,理解空气污染的健康效应又是一个复杂命题,既要考虑不同类型的污染物同时也要考虑相关疾病的复杂性。然而越来越多的研究表明,表观遗传学在空气污染相关疾病的发生、发展中发挥着重要的作用。空气污染物可引起DNA甲基化、组蛋白修饰和miRNA表达等表观遗传学改变,这种改变往往发生在疾病产生的早期,因此相关研究不仅可以了解疾病的发病机制,而且还为疾病早期诊断和预防筛选可能的标志物。本文综述了表观遗传学的几种修饰方式和空气污染物造成不良健康损伤机制的一些研究进展。     

城市环境管理：后续行动

前面有一期《产业与环境》（Volume 23, No.1－2）是关于城市环境管理（UEM）的.这确实是一个越来越复杂的挑战，因此这里再提供另外一个观点.在历史上，城市曾经是经济和社会发展的推动力.城市化和高收入、改善健康、提高文化、提高生活质量和其他福利相联系.但是城市化在带来福利的同时，却对环境和社会造成了损害.这些损害包括多种多样的问题，从缺乏清洁饮用水到城市空气污染、温室气体的排放，等等.除了经济活动，庞大的人口大军也是城市增长的原因.今天推动城市化的一些主要力量是工作从农业到工业的转移和城市地区经济机会的集中.…     

苏州市区空气污染对园林香樟,枫香植物生长的影响

本文测定了苏州市园林和效区香樟、枫香的光合作用、叶绿素含量、新梢长度、叶片长度与叶片宽度等生长因子,发现市区园林植物生长均受到抑制,其原因是空气污染造成的。提出了调整产业结构、集中供热、点源和面源控制、地面扬尘以及汽车气控制的整治措施,加以根治苏州区空气污染,改善城市生态环境。     

EDXRF法分析空气滤膜

随着对居民区和工业区空气污染监测日益的要求,空气,水和土壤污染已经成为环境保护局,相关实验室,城市发展当局和卫生部门的主要分析项目.     

常州市2007年降水酸度及离子含量特征

降水是对大气污染物的一个快速有效的净化过程.降水的化学成分取决于云团的净化过程,以及大气中的气相气溶胶和颗粒物气溶胶.由于汽车尾气以及工业污染,导致气溶胶成分的复杂性,从而增加了降水化学成分的复杂性.为了了解一个城市的空气污染情况,必需深入地研究它的降水.尽管我国南方的SO2和NOX排放量小于北方,但是我国南方的酸雨状况明显比北方严重,特别是华东地区和西南地区.常州市地处长三角的中心地带.长三角区域内各个城市降水化学的研究报道多集中于上海和南京等大城市.     

北京市天然气公交车的发展现状及前景

随着石油资源短缺、城市空气污染问题的日益严重,天然气汽车作为一种实用的低排放汽车逐渐得到了重视和应用。本文首先通过汽车与能源、汽车与环境两个方面,分析说明了北京市发展天然气汽车的重要性;然后简要介绍了北京市天然气公交车的发展现状、未来几年的发展规划,最后指出了实现发展规划的条件和政策。     

Water spray geoengineering to clean air pollution for mitigating haze in China’s cities

In the past 30 years, China has suffered from air pollution and heavy haze created by fast industrial growth and economic expansion. This article reviews the techniques for remediation of air pollution. Then, I propose a geoengineering method for mitigating air pollution and haze in China’s cities by using water to scavenge air pollution. Here, water should be sprayed into the atmosphere like watering garden. The scientific rationale and mechanism for the geoengineering scheme are explained. It is found that precipitation scavenging coefficients are very sensitive to the size distributions of both aerosol and raindrops, and rain intensity. I found that the water spray geoengineering method can reduce the PM_2.5 pollution in the atmosphere very efficiently to 35 μg m^?3 level in a very short time period from few minutes to hours or days, depending on the precipitation characteristics. In addition, the water spray geoengineering method has excellent advantages such as rapidity, already available technology, low cost, and a nature-like process. This proposed geoengineering scheme can be one of the answers for fighting air pollution in the cities globally.     

建立南京、镇江、扬州三市大气污染联防联控机制探讨

随着城市规模的快速扩张,区域内城市连片开发和建设,受大气环流及大气化学的双重作用,城市之间大气污染物交叉流动、相互传输,使相邻几个城市的大气污染相互影响,区域性大气污染问题越来越严重.该文以南京、镇江、扬州三市为例,通过分析区域性大气污染问题及其成因,认为建立宁、镇、扬大气污染联防联控机制十分必要,对于改善区域大气环境质量,促进区域经济社会可持续发展有重要意义.     

Air quality improvement in Los Angeles—perspectives for developing cities

Air quality improvement in Los Angeles can inform air quality policies in developing cities. Emission control efforts, their results, costs and health benefits are briefly summarized. Today's developing cities face new challenges including regional pollution. Air quality issues in Beijing are briefly compared and contrasted with Los Angeles. Opportunities for co-benefits for climate and air quality improvement are identified. Air quality improvement in Los Angeles, California is reviewed with an emphasis on aspects that may inform air quality policy formulation in developing cities. In the mid-twentieth century the air quality in Los Angeles was degraded to an extent comparable to the worst found in developing cities today; ozone exceeded 600 ppb and annual average particulate matter <10 mm reached ~150 mg·m⁻³. Today's air quality is much better due to very effective emission controls; e.g., modern automobiles emit about 1% of the hydrocarbons and carbon monoxide emitted by vehicles of 50 years ago. An overview is given of the emission control efforts in Los Angeles and their impact on ambient concentrations of primary and secondary pollutants; the costs and health benefits of these controls are briefly summarized. Today's developing cities have new challenges that are discussed: the effects of regional pollution transport are much greater in countries with very high population densities; often very large current populations must be supplied with goods and services even while economic development and air quality concerns are addressed; and many of currently developing cities are located in or close to the tropics where photochemical processing of pollution is expected to be more rapid than at higher latitudes. The air quality issues of Beijing are briefly compared and contrasted with those of Los Angeles, and the opportunities for co-benefits for climate and air quality improvement are pointed out.     

Air pollution and its control in China

The rapid growth of China’s economy has led to severe air pollution characterized by acid rain, severe pollution in cities, and regional air pollution. High concentrations are found for various pollutants such as sulfur dioxides (SO₂), nitrogen oxides (NO_x), and fine particulates. Great efforts have thus been undertaken for the control of air pollution in the country. This paper discusses the development and application of appropriate technologies for reducing the major pollutants produced by coal and vehicles, and investigates air quality modeling as an important support for policy-making.     

‘Effortless Perfection:’ Do Chinese cities manipulate air pollution data?

This paper uses unique data on daily air pollution concentrations over the period 2001–2010 to test for manipulation in self-reported data by Chinese cities. First, we employ a discontinuity test to detect evidence consistent with data manipulation. Then, we propose a panel matching approach to identify the conditions under which irregularities may occur. We find that about 50% of cities reported dubious PM₁₀ pollution levels that led to a discontinuity at the cut-off. Suspicious data reporting tends to occur on days when the anomaly is least detectable. Our findings indicate that the official daily air pollution data are not well behaved, which provides suggestive evidence of manipulation.     

城市大气环境监测优化布点模糊优选模型及应用实例

文章根据城市大气环境监测优化布点的模糊性，提出了一种模糊环境条件下的模糊聚类与模糊识别理论模型，并且在山东省肥城等市成功应用。结合统计方法确定出的大气监测优化点位，不但具有代表性和整体性，而且具有较高的分辨率，能快速准确地、最大范围地反映出该区域的环境空气质量状况、大气污染扩散规律、污染源分布特点、污染气象及地理位置特征，为环境管理和政府决策提供可靠依据。     

Local production,downward and regional transport aggravated surface ozone pollution during the historical orange-alert large-scale ozone episode in eastern China

Increasing severe and persistent ozone pollution in China has resulted in serious harm to human health in recent years, yet the precise pollution sources are poorly known because there is few knowledge on large-scale extreme ozone episodes. Here, we studied the formation of the historical orange-alert regional ozone episode in eastern China on 6 June, 2021, by combining process analysis, integrated source apportionment modelling, and chemical and meteorological data. Results show that during the pollution episode, 94% of cities in eastern China suffered ozone pollution, and 39% had daily maximum 8-h average ozone concentrations higher than 100 ppb. This is explained by favorable local ozone formation and transports provided by the prevailing northwestern winds in the upper air, and by sinking atmospheric motions favoring the persistence of high surface ozone concentrations. During daytime, local photochemical production induced an ozone increase of 0.3–28.4 ppb h^?1 and vertical transport induced an ozone increase of 0.4–56.1 ppb h^?1. As a consequence, vertical downward transport of ozone generated in the upper air by photochemical reactions aggravated surface ozone pollution. Surface ozone concentrations include 25.8–53.9% of ozone from local provincial emissions, 0–42.6% of ozone from inter-regional transports from neighboring regions, 4.6–23.1% of ozone from outer-regional transport, and 13.6–52.9% of ozone from boundary conditions in the selected cities. Overall, our findings show that favorable meteorological conditions promoted the chemical productions of ozone on the surface and at high altitudes, thus resulting in this heavy ozone pollution. In addition, regional and vertical downward transports of aloft ozone further aggravated the surface ozone pollution, leading to the large-scale extreme ozone pollution episode.

     

Highway toll and air pollution: Evidence from Chinese cities

Most highways in urban China are tolled to finance their construction. During the eight-day National Day holiday in 2012, highway tolls were waived nationwide for passenger vehicles. We use this to identify the effects of highway tolls on air pollution. Using daily pollution and weather data for 98 Chinese cities in 2011 and 2012 and employing both a regression discontinuity design and differences-in-differences method with the 2011 National Day holiday as a control, we find that eliminating tolls increases pollution by 20% and decreases visibility by one kilometer. We also estimate that the toll elasticity of air pollution is −0.15. These findings complement the scant literature on the environmental impact of road pricing.     

沙尘与大雾天气对京津石空气质量影响

采用北京、天津、石家庄2001-2010年沙尘与大雾天气的统计数据以及城市空气污染指数（API）,分析北京、天津、石家庄3市空气污染指数变化特征及大雾和沙尘天气下北京、天津、石家庄3市空气质量情况,进而得出沙尘大雾天气对京津石空气质量的影响。结果表明：2001-2010年间北京、天津、石家庄3市API总体呈下降趋势,天津、石家庄相对于北京空气质量改善较为明显,且空气质量夏季〉秋季〉春冬季。沙尘天气条件下,北京、天津、石家庄3市API平均值分别为255、179和167,空气质量出现良的比率天津为24%,北京、石家庄为10%左右,出现重污染的比率北京高达50%以上,天津和石家庄均在20%左右;3市沙尘天气高频次均出现在3-5月份,但北京沙尘天气发生次数远大于天津和石家庄。大雾天气条件下,北京、天津、石家庄3市API平均值为185、130和167,空气质量出现优或良的比率：天津〉石家庄〉北京,北京和石家庄出现重污染的比率均接近30%,天津不到10%,所以大雾天气对3市空气质量影响较小,大雾天气频次的变化波动并未对该地区空气质量的年际变化造成显著影响,3市高频次大雾天气集中在10-12月份,对该时段内空气污染呈现加重趋势有一定的贡献。所以沙尘和大雾天气均对北京、天津和石家庄空气质量存在不利影响,其中对北京影响最为严重,对天津影响最轻。整体上沙尘对3市的空气质量影响较大,大雾天气影响较小。     

大气颗粒物暴露与健康效应研究进展

大气颗粒物一直是影响我国大多数城市空气质量的首要污染物,且呈现出与欧美不同的煤烟、机动车尾气以及开放源复合型污染并存的高浓度污染态势,已有研究发现颗粒物的短期或长期暴露均会对人体产生不良的健康效应。本文从环境科学、暴露科学、环境流行病学和环境毒理学研究等方面系统综述了大气颗粒物健康效应研究的方法和进展,可为我国的大气颗粒物健康效应研究与大气颗粒物环境质量标准的修订提供方法学参考和经验借鉴。目前我国PM10污染尚未得到有效控制,细颗粒物(PM2.5)的污染也已引起关注,建议在不同区域开展空气污染健康效应的系统研究。