Improving the indoor air quality using the individual air supply system

Indoor air quality attracts great interest. Many dwellings are ventilated naturally. The article presents the gravity system conversion into individual air supply system, which can be equipped with air fan. This solution’s impact on the interior microclimate was analyzed. The proposed solution uses the lower natural ventilation ducts sections, which are not normally used as air supply channels to bring air to the housing. Exhaust grilles were located in the adjacent rooms. Individual air supply system with switched off fan improves indoor air quality insufficiently; however, switching on the device causes a very significant change. A large carbon dioxide concentration reduction (which was used as an air quality indicator) has been confirmed by rigorous statistical analysis, the results of which were presented in the article.     

浙江慈溪市土地生态质量调查和评估

土壤、大气、水和农产品质量共同构成土地生态质量的内涵。通过慈溪市基本农田质量调查试点项目,开展了高精度土壤地球化学调查和农产品、灌溉水、大气质量调查,建立了土地生态质量评估模型。以土壤地球化学质量评估为基础,进行了大气、水、农产品综合质量评估,以及慈溪市农用地土地生态质量评价。评价显示,慈溪市农用地土地生态质量绝大部分优良,只有局部如城市周边等地存在生态风险。试点成果为浙江省国土资源特别是基本农田的数量、质量和生态管护并重的精细化管理提供了示范和依据。     

太原市大气SO2污染的变化规律

利用太原市近年来大气环境监测数据，分析了太原市大气中ＳＯ２的污染程度及日、月、年变化规律，并引用灰色系统理论ＧＭ（１，１）模型对１９９５年的ＳＯ２污染程度进行预测。同时讨论了污染原因。，并提出一些改善大气环境质量的建议。     

Impact of global climate change on regional air quality: Introduction to the thematic issue

Despite the major international efforts devoted to the understanding and to the future estimate of global climate change and its impact on regional scale processes, the evolution of the atmospheric composition in a changing climate is far to be understood. In particular, the future evolution of the concentration of near-surface pollutants determining air quality at a scale affecting human health and ecosystems is a subject of intense scientific research. This thematic issue reviews the current scientific knowledge of the consequences of global climate change on regional air quality and its related impact on the biosphere and on human mortality. This article provides a presentation of the key issues, summarizes the current knowledge, and introduces the thematic issue.     

Design of an environmental assessment model on the effect of vehicle emission in greater Tehran on air pollution with economic sensitivity

Air pollution is the presence of pollutants in the atmosphere from anthropogenic or natural substances in quantities likely to harm human, plant or animal life; to damage human-made materials and structures; to bring about changes in weather or climate; or to interfere with enjoyment of life or property. With regard to the quality of air in most of the megacities of the world, vehicular air pollution plays an important role in deteriorating air quality. Air pollution in Tehran (Capital of the Islamic Republic of Iran) occurs in highly urbanized areas due to mobile anthropogenic sources which in-turn is hastened by unfavorable tohion sector is responsible for much of urban air pollution and can result in high ambient concentrations that harm people, structures, and environment. This paper examines and estimates the tonnage, concentrations and impacts of air pollutants along with control measures aimed at reducing the effect of pollutants released by transportation navigation, in Tehran.     

旅游业的环境影响综合评价与对策

旅游业对自然环境有正反两方面的影响。反面影响包括对水体和大气环境的影响,对动植物的影响,对土壤和沙丘的侵蚀,以及影响审美。正面影响包括建立自然保护区,保护海洋、植被、湿地,促进连际土地开发和教育民众。促进旅游业永续发展的对策有：对旅游业进行选择;对旅游区进行环境规划;对旅游业的环境影响进行实验追踪,建立综合性模式研究旅游业的累积环境影响。     

环境汞调查报告

通过测定某部大院内土壤、大气环境中汞的含量、赋存状态，并对所得数据进行处理分析研究，得出某部大院环境中汞的分布特点与存在形式，从而对该地区汞的环境容量及其分布可能对人体健康产生的影响和危害有了一个较准确的认识与评价。     

Recent innovations in hazard and risk analysis

Air pollution has been a major transboundary problem and a matter of global concern for decades. Climate change and air pollution are closely coupled. Just as air pollution can have adverse effects on human health and ecosystems, it can also impact the earth’s climate. As we enter an era of rapid climate change, the implications for air quality need to be better understood, both for the purpose of air quality management and as one of the societal consequences of climate change. In this study, an attempt has been made to estimate the current air quality to forecast the air quality index of an urban station Kolkata (22.65°N, 88.45°E), India for the next 5 years with neural network models. The annual and seasonal variability in the air quality indicates that the winter season is mostly affected by the pollutants. Air quality index (AQI) is estimated as a geometric mean of the pollutants considered. Different neural network models are attempted to select the best model to forecast the AQI of Kolkata. The meteorological parameters and AQI of the previous day are utilized to train the models to forecast the AQI of the next day during the period from 2003 to 2012. The selection of the best model is made after validation with observation from 2013 to 2015. The radial basis functional (RBF) model is found to be the best network model for the purpose. The RBF model with various architectures is tried to obtain precise forecast with minimum error. RBF of 5:5-91-1:1 structure is found to be the best fit for forecasting the AQI of Kolkata.     

Modelling the regional effects of climate change on air quality

The life cycle of pollutants is affected by chemical as well as meteorological factors, such as wind, temperature, precipitation, solar radiation. Therefore, climatic changes induced by anthropogenic emissions of greenhouse gases may be expected to have significant effects on air quality. Because of the spatial variability of the pollutant emissions and climate-change signals, these effects are particularly relevant at the regional to local scales. This paper first briefly reviews modelling tools and methodologies used to study regional climate-change impacts on air quality. Patterns of regional precipitation, temperature, and sea-level changes emerging from the latest set of general circulation model projections are then discussed. Finally, the specific case of climate-change effects on summer ozone concentrations over Europe is presented to illustrate the potential impacts of climate change on pollutant amounts. It is concluded that climate change is an important factor that needs to be taken into account when designing future pollution-reduction policies.     

资料同化在空气质量预报中的应用

随着数值模式的不断完善和观测技术的不断提高,资料同化逐渐成为能够进一步提高数值预报水平的一种有效方法。20世纪70年代,资料同化开始引入空气质量预报领域,成为当前大气环境科学研究的一个新方向。简要介绍了资料同化的含义,较详细地介绍了Kalman滤波法、四维变分同化法、牛顿松弛法的基本思想和优缺点,重点阐述了国内外资料同化在空气质量预报中的研究应用情况,最后指出资料同化应用于空气质量预报时存在的问题和今后的研究方向。     

云南大理地区1989—2019年期间气候变化及对洱海水质的影响

依据1989年至2019年云南大理地区所辖12个气象站点的气候数据和洱海水质监测资料等文献,分析大理地区气候变化特征和洱海富营养化变化趋势,并总结洱海水质综合营养状态指数与降水量、气温的相互关系。结果表明,1989年至2019年期间,大理地区的年平均气温呈波动上升趋势,气候变暖明显,冬季气温升温幅度最大;年降水量总体呈波动下降趋势,秋季降水量减少最为显著。洱海水质的综合营养状态指数及单因子总氮、总磷、高锰酸盐指数等总体呈升高趋势,而水体透明度呈降低趋势;进一步可分成2个阶段,即2003年之前呈快速上升或下降变化趋势;2003年之后呈波动稳定趋势。洱海综合营养状态指数与年平均气温呈正相关,与年降水量呈负相关关系;总氮、水体透明度分别与年平均气温正相关和负相关,与年降水量则呈负相关和正相关;而总磷与冬季平均气温、高锰酸盐指数与夏季或冬季平均气温均呈正相关关系。年内变化上,洱海污染指数、综合营养状态指数在最近的2015—2019年期间呈现6—10月份明显增高,显示非汛期水质明显好于汛期状况。总之,1989—2019年期间,受大理地区气温升高、降水量减少导致入湖水量减少的影响,洱海综合营养状态指数呈升高趋势,湖泊富营养化进程加剧状况没有得到改善,洱海水环境仍然比较脆弱。     

Assessment of spatial variations of particulate matter (PM<Subscript>10</Subscript> and PM<Subscript>2.5</Subscript>) in Bahrain identified by air quality index (AQI)

The rapid urbanization, industrialization, modernization, and the frequent Middle Eastern dust storms have negatively impacted the ambient air quality in Bahrain. The objective of this study is to identify the most critical atmospheric air pollutants with emphasis on their potential risk to health based on calculated AQI (air quality index) values using EPA approach. The air quality datasets of particulate matters (PM₁₀ and PM_2.5), ozone (O₃), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and carbon monoxide (CO) were measured in January 2012 and August 2012 using five mobile air quality monitoring stations located at different governorates. The results of this study demonstrated that PM₁₀ and PM_2.5 are the most critical air pollutants in Bahrain with PM_2.5 prevailing during January 2012 and PM₁₀ prevailing during August 2012. The corresponding AQI categories were utilized to evaluate spatial variability of particulate matters in five governorates. The impact of meteorological factors such as ambient air temperature, wind speed, relative humidity, and total precipitation on ambient air quality were discussed. The analysis demonstrated that the highest PM₁₀ concentrations were observed in the Northern Governorate while the highest PM_2.5 concentrations were observed in the Capital, Central, and Northern Governorates during August 2012. It was observed that the levels of PM_2.5 pollution were higher within proximity of the industrial zone. The results suggested that the average PM_2.5/PM₁₀ ratio in August 2012 was lower than in January 2012 due to the Aeolian processes. This study concludes that higher wind speed, total precipitation, relative humidity rates, and lower ambient air temperature in January 2012 assisted with the dissipation of particulate matter thus lowering the pollution levels of both PM₁₀ and PM_2.5 in comparison to August 2012.     

Geo-environmental quality assessment in Jharia coalfield,India, using multivariate statistics and geographic information system

A study on geo-environmental quality assessment in Jharia coalfield, India, has been attempted using multivariate statistical analysis and geographic information system (GIS) modelling techniques. Water quality index, calculated for each sample network station in the study area to assess the suitability of water for human consumption, revealed very poor to poor quality surface water and mine water. Air quality indexing indicated that there is no sample station with clean air as per the Indian standards, which indicate the hazardous air quality. Multi-criteria evaluation (MCE), a potential GIS tool, has been applied to the delineation of various degrees of stressed villages in terms of quality of life (QoL). The role of various geo-environmental parameters such as quality of groundwater, surface water, mine water and air together with village population densities has been emphasized for delineation of the environmentally stressed villages in Jharia coalfield. The integrated cluster analysis and MCE approach provide an improved means to geo-environmental quality assessment in Jharia coalfield in terms of QoL. The assessment study is aimed to be used for future coal mining, ensuring ecologically sustainable industrial development, particularly in a coalfield.     

Stress of urban energy consumption on air environment

With rapid urbanization and heavy industrialization as well as the rapid increase of cars in China, the effect of energy consumption on urban air environment is increasingly becoming serious, and has become a hot topic for both scholars and decision-makers. This paper explores the effect mechanism and regulation of urban energy consumption on the air environment, and summarizes the framework of the stress effect relationship and the evolutionary process. In accordance with the effect relationship of the internal factors between the two, analytic approaches studying the stress effect of urban energy consumption on air environment are proposed, including the analysis of air environment effects caused by urban energy consumption structure change, and the analysis of air environment effects caused by urban energy economic efficiency change, as well as a decomposition analysis of air pollutant emission caused by urban energy consumption. Applying the above-mentioned approaches into a case study on Beijing City, this paper analyzes the effect relationship among urban energy consumption structure improvement, energy economic efficiency increase and air quality change since the period when Beijing City officially proposed to bid for the 2008 Olympic Games in 1998. In addition, it further analyzes the effect and contribution of urban industrial activity level, industrial economic structure, industrial energy intensity, and industrial energy structure as well as emission coefficients on the change in industrial SO₂ emission, which can provide valuable information to the government for making comprehensive environmental policies, with the use of the logarithmic mean Divisia index (LMDI) method. It is shown that under the precondition that the industrial economy maintain a continuous and rapid increase, improvements in energy intensity and a decline in emission coefficients are the main means for reducing Beijing’s industrial SO₂ emissions.     

Assessing precision and accuracy of atmospheric emission inventories

Assuming that state-of-the-art air quality models are accurate, then the precision and accuracy of their results directly depend on the precision and accuracy of their geographical, meteorological and emission input data. There are important applications, such as open pit mining, in which emission data are the main source of uncertainty. In such cases, historical air quality experimental data are typically available. The present work proposes a backward air quality simulation approach to assess the accuracy of emission inventories for these applications, with the goal of identifying sources that are over or underestimated. This approach consists of finding constants of the linear combination of the estimated emission that maximize R ² and make the slope equal to one in the linear correlation analysis when the results from the air quality model are compared to the experimental measurements of air quality. This methodology was applied to the case of the mining region in northern Colombia. As one of the largest open pit coal mining regions in the world, this region consists of seven independent mines with no relevant additional sources of emission. Use of the proposed methodology allowed quantification of the amount by which companies over or underestimated their emission, as well as quantification of uncertainties due to sources not considered in the model but that locally affect each monitoring station.     

溶液除湿空调系统模拟方法及应用

溶液除湿空调系统由于在改善室内空气品质、利用低温余热、高效蓄能和可实现温、湿度独立控制等方面的突出优点，已经引起广泛的关注，并逐渐应用于工程实践中。本文以上海某生态示范建筑中采用的热泵驱动的溶液除湿空调系统为例，介绍了这种系统的工作原理，并建立了系统模拟的数学模型。通过模拟结果与实测结果的比较，验证了数学模型的可靠性，并应用系统模型对溶液除湿新凤机和再生器的性能进行了深入分析。     

Using grey Holt–Winters model to predict the air quality index for cities in China

The randomness, non-stationarity and irregularity of air quality index series bring the difficulty of air quality index forecasting. To enhance forecast accuracy, a novel model combining grey accumulated generating technique and Holt–Winters method is developed for air quality index forecasting in this paper. The grey accumulated generating technique is utilized to handle non-stationarity of random and irregular data series and Holt–Winters method is employed to deal with the seasonal effects. To verify and validate the proposed model, two monthly air quality index series from January in 2014 to December in 2016 collected from Shijiazhuang and Handan in China are taken as the test cases. The experimental results show that the proposed model is remarkably superior to conventional Holt–Winters method for its higher forecast accuracy.     

燃烧麦秸对大气颗粒物中多环芳烃含量的影响

通过对集中燃烧麦秸前后北京市大气颗粒物中多环芳烃的分析，结合麦秸燃烧排放气体中相关成分的测试，说明燃烧麦秸对大气中多环芳烃的含量有很大的影响，提示有关部门应对之采取措施，防止大气环境质量因此而受到破坏。     

Contribution of atmospheric processes to the degradation of air quality: case study (Sohar Industrial Area,Oman)

The impact of the air pollution generated by any industrial activities may be further aggravated if the location of the industrial area is exposed to certain atmospheric characteristics. Under such conditions, the likelihood of accumulation of local air pollution is high. This paper uses two approaches (statistical and numerical simulation) to investigate the contribution of atmospheric processes towards degradation of air quality. A case study of the two approaches was conducted over Sohar Industrial Area in the Sultanate of Oman. Measured wind data were used to account for specific atmospheric characteristics such as stagnation, ventilation, and recirculation using the statistical approach. In the second approach, numerical weather prediction model was used to simulate mesoscale circulation phenomena such as sea breeze and its contribution to the processes affecting the air quality. The study demonstrates that the atmospheric processes appear to contribute substantially to the degradation of air quality in the Sohar Industrial Area. The statistical analysis shows that the atmospheric dilution potential of Sohar Industrial Area is prone to stagnation and recirculation, rather than ventilation. Moreover, model simulation shows that there is a seasonal variation in the contribution of atmospheric processes to the degradation of the air quality at Sohar Industrial Area.     

Impact of COVID-19 Lockdown on Air Quality in Moscow

Doklady Earth Sciences - The results of an analysis of changes in the atmospheric air quality in Moscow during the lockdown period and the decline in business activity caused by the COVID-19...