Estimating Air Quality in a Traffic Tunnel Using a Forecasting Combination Model

This study performs a field analysis of the diffusion collection rate coefficients of radial geometry passive samplers to measure NO₂ in a Mediterranean coastal area. The study shows that the collection rate coefficients are not constant and depend on certain environmental parameters as well as on the levels of some co-pollutants. A mathematical model, which explains the variation of the collection rate coefficient, has been established.     

Variation in spatial pattern of criteria air pollutants before and during initial rain of monsoon

Spatial patterns of various criteria air pollutants,like SO₂, NO₂, O₃, and TSP were studied atShahdara National Ambient Air Quality Monitoring stationin Delhi (India) in July 1999. The minimum pollutantconcentrations were observed during morning hours,whereas the highest concentrations were found during thelate night hours, which seem to be related with thevehicular emission. Pre-monsoon daily ambient airquality spatial pattern was compared with the spatialpattern during initial and subsequent rain shower ofmonsoon. These spatial patterns were found to beessentially the same before and during rain, however asignificant decrease in SO₂, NO₂ and TSPconcentrations (40-45%) was observed after initial andsubsequent rains of the monsoon, demonstrating theimportance of rainfall in the scavenging of thesecriteria air pollutants.     

Outdoor-indoor air quality in Riyadh: SO2, NH3, and HCHO

A funded research project was conducted during the period July1992 through November 1994. The project was designed to evaluateindoor and ambient air quality in and around buildings of different types and uses in Riyadh, the capital of Saudi Arabia.Thirty intercity buildings and two outercity (background) siteswere carefully selected and monitored for air quality. Ten airpollutants, together with relevant meteorological parameters, were monitored indoor and outdoor at each site continuously andsimultaneously for a period of two weeks covering summer and winter seasons.This article discusses the results obtained for sulfur dioxide (SO₂), ammonia (NH₃) and formaldehyde (HCHO). Results of this investigation revealed that most sites had on the averageexceeded the recommended standards for SO₂ and NH₃ bothindoor and outdoor, with indoor levels being worse than outdoorduring winter time. Several sites also showed high levels of HCHO, with outdoor levels being consistently higher than indoor.Statistical and frequency analyses were performed on the collected data, showing seasonal and sector by sector variability, and outdoor-indoor correlations.     

Ambient Air Quality Status in Raniganj-Asansol Area, India

This investigation presents the assessment of ambient air quality with respect to suspended particulate matter (SPM), sulphur dioxide (SO₂) and oxides of nitrogen (NO_X) at four sites (RGC, SRS, BBC and BCC) in the Raniganj-Asansol area in West Bengal, India. Ambient air was monitored with a sampling frequency of twenty four hours (3 × 8 hours) at each site on every alternate day (3 days a week) covering a period of one year. A total of 429 samples were collected from RGC, 429 from SRS and 435 each from the BBC and BCC sites. Meteorological parameters such as temperature, relative humidity, wind-speed and wind-direction were also recorded simultaneously during the sampling period. Monthly and seasonal variation of these pollutants have been observed and recorded. The annual average and range values have also been calculated. Results of the investigation indicates that the 95th percentile values of SPM levels exceed the limits (200 g m^-3) at RGC, SRS and BBC sites and is within the limit of 500 g m^-3 at the BCC sites. The 95th percentile values of SO₂ levels did not exceed the reference level at any of the monitoring stations. The 95th percentile values of NO_X are found to be exceeding the limit (80 g m^-3) at RGC, SRS and BBC sites but is within the prescribed limit of 120 g m^-3 at the BCC site. Further, it has been observed that the concentrations of the pollutants are high in winter in comparison to the summer or the monsoon seasons. Results of the investigation indicates that industrial activities, indiscriminate open air burning of coal by the local inhabitants for cooking as well as coking purposes, vehicular traffic, etc. are responsible for the high concentration of pollutants in this area.     

Interpretation of roadside PM10 monitoring data from Sunderland,United Kingdom

Roadside PM₁₀ has been monitored by Partisol® at three sitesin Sunderland between August 1997 and February 1998. The sites chosen were an inner city kerbside site; a roadside site adjacentto a dual carriageway on the outskirts of Sunderland with an openaspect; and a rural site.The results indicate that there is a seasonal variation in the relationship between the sites in terms of monitored PM₁₀.In the winter there is a poor correlation between the sites whereas in the summer significant correlations are obtained. Of the sites monitored PM₁₀ is consistently highest at the inner city roadside site. During the summer, exceedances of theU.K. 50 g m^-3 standard (DETR, 2000) are associated with conditions suitable for the build-up of photochemical pollutionhowever during the winter period exceedances are recorded duringa variety of weather conditions.At the dual carriageway site PM_2.5 has also been recorded and contributions to measured PM₁₀ are 77% in summer and68% in winter. The results illustrate a number of inconsistencies between this study utilising the Partisol® andothers reporting results where PM₁₀ has been monitored by TEOM®.     

Monitoring of Criteria Air Pollutants in Bursa, Turkey

The concentrations of criteria air pollutants such as CO, NO_x (NO + NO₂), SO₂ and PM were measured in the period of May 2001 and April 2003 in the city of Bursa, Turkey. The average concentrations for this period were 1115±1600 μg/m³, 29±50 μg/m³, 51±24 μg/m³, 79±65 μg/m³, 40±35 μg/m³, 98±220 μg/m³, for CO, NO, NO₂, NO_x, SO₂ and PM, respectively. Temporal changes in concentrations were analyzed using meteorological factors. Correlations among pollutant concentrations and meteorological parameters showed weak relations nearly in all data. Lower concentrations were observed in the summer months while higher concentrations were measured in the winter months. The increase in winter concentrations was probably due to residential heating. Pollutants were associated with each other in order to have information about their origin. NO_x/SO₂ ratio was also examined to bring out the source origin contributing on air pollution (i.e., traffic or stationary).     

Study of urban atmospheric pollution in Navarre (Northern Spain)

An ambient air quality study was undertaken in two cities (Pamplona and Alsasua) of the Province of Navarre in northern Spain from July 2001 to June 2004. The data were obtained from two urban monitoring sites. At both monitoring sites, ambient levels of ozone, NO_x, and SO₂ were measured. Simultaneously with levels of PM₁₀ measured at Alsasua (using a laser particle counter), PM₁₀ levels were also determined at Pamplona (using a beta attenuation monitor). Mean annual PM₁₀ concentrations in Pamplona and Alsasua reached 30 and 28 μg m⁻³, respectively. These concentrations are typical for urban background sites in Northern Spain. By using meteorological information and back trajectories, it was found that the number of exceedances of the daily PM₁₀ limit as well as the PM₁₀ temporal variation was highly influenced by air masses from North Africa. Although North African transport was observed on only 9% of the days, it contributed the highest observed PM₁₀ levels. Transport from the Atlantic Ocean was observed on 68% of the days; transport from Europe on 13%; low transport and local influences on 7%; and transport from the Mediterranean region on 3% of the days. The mean O₃ concentrations were 45 and 55 μg m⁻³ in Pamplona and Alsasua, respectively, which were above the values reported for the main Spanish cities. The mean NO and NO₂ levels were very similar in both sites (12 and 26 μg m⁻³, respectively). Mean SO₂ levels were 8 μg m⁻³ in Pamplona and 5 μg m⁻³ in Alsasua. Hourly levels of PM₁₀, NO and NO₂ showed similar variations with the typically two coincident maximums during traffic rush hours demonstrating a major anthropogenic origin of PM₁₀, in spite of the sporadic dust outbreaks.     

2001年～2008年及奥运会期间天津市大气污染特征分析

根据天津市大气质量监测数据,对2001年～2008年及奥运会期间天津市大气污染特征和主要大气污染物的变化规律进行了分析。结果表明,2001年～2008年天津市的PM10、SO2和NO2污染总体呈下降趋势,但质量浓度仍相对较高。2008年8月奥运会期间天津市PM10和SO2质量浓度达到国家空气质量二级标准,NO2质量浓度达到国家空气质量一级标准,空气质量良好。天津市PM10污染相对稳定,SO2和NO2的污染分布呈现明显的季节性,时间上表现为冬强夏弱。气象条件对污染物浓度影响明显,沙尘、大雾等天气可使污染物浓度急剧升高。     

Air quality assessment along Dhanbad - Jharia road

Road ambient air pollution status along Dhanbad – Jharia road isstudied and presented in this article. The selection of this areais made considering the importance of the road in Dhanbad district and the nature of activities taking place along the road, which reflect that the portion of road upto Dhansar can be considered as having commercial areas on both sides and that from Dhansar to Jharia as having industrial areas on both sides.For the assessment of the ambient air quality along the road monitoring is done at the following five locations: Indian Schoolof Mines (ISM), main gate; Bankmore; Dhansar police check post; Dhansar opencast project agent office and a residential house beside the Rajapur opencast project. The location of ISM, maingate is specially chosen as this represents a commercial shoppingcomplexes and the situation can be compared with that at Bankmore. Monitoring of ambient air quality is done following thestandard procedure prescribed in IS: 5182. In addition the concentration of lead, zinc, copper, iron, manganese, cadmium metals in SPM is also monitored. The ambient air quality is monitored in the months of September and November 1999, respectively, to represent monsoon and winter seasons. The SPM concentration observed at all the five locations in the winterseason is more than the permissible limits for commercial andindustrial areas. However, in the monsoon season, the SPM concentration is higher than the permissible limit at the twocommercial locations, i.e., ISM gate and Bankmore, while it isless than the prescribed limit for industrial areas at the remaining three locations. At the ISM gate and Bankmore the SPM generation is mainly by vehicular traffic while at other three locations it was in addition due to mining and other activities.     

宁波市大气污染概况及影响因素分析

为研究宁波市大气污染状况及其影响因素,利用2013—2018年宁波市国控站点实时监测污染物数据以及气象数据,探讨分析了宁波市大气污染特征以及所受气象因素的影响概况。结果表明：宁波市颗粒物污染和O₃污染呈现典型的季节性特征,颗粒物浓度冬季最高,O₃最大滑动8 h平均质量浓度春、秋季最高。宁波市O₃污染问题越来越突出,且呈现出春、秋季O₃超标天数最多的季节变化特征。O₃小时质量浓度与气温和太阳辐射成正相关关系,NO₂和颗粒物浓度与气温成负相关关系。NO₂与O₃浓度成负相关关系,与颗粒物浓度成正相关关系。     

“十一五”时期乌鲁木齐市大气污染特征及影响因素分析

为全面了解"十一五"时期(2006—2010年)乌鲁木齐市大气污染状况,评估污染源治理及气象条件对空气质量变化的影响,利用2001年1月—2010年12月主要大气污染物浓度数据和同期地面气象资料,总结"十一五"时期乌鲁木齐市大气污染变化特征,重点分析其变化原因。结果表明:"十一五"时期PM10和SO2年均浓度分别比"十五"下降1.7%和10.3%,采暖季降幅最明显,分别达到2.2%和21.9%;而NO2年均浓度比"十五"升高8.9%,非采暖季增幅最大,为11.7%。2006—2010年PM10、SO2年均浓度整体呈下降趋势,NO2浓度有升高趋势。5年中非采暖季各污染物浓度均达标,采暖季PM10和SO2超标倍数逐年减小,煤烟型污染特征仍然典型。污染源管控(特别是减排工程实施)是"十一五"时期SO2和PM10浓度下降的重要原因,气象条件作用相对有限。NO2浓度升高主要与机动车保有量逐年增加和氮氧化物治理启动滞后有关。     

台州市酸雨污染现状及其对策分析

通过对近十年来的酸雨监测资料的收集分析,结合同期台州市大气环境中二氧化硫和氮氧化物的监测数据,采用秩相关系数法,对酸雨污染趋势和成因进行分析和讨论,并提出针对性措施,以期为台州市以及类似地区的大气污染、酸雨污染等防治工作提供政策参考。     

被动式个体采样器在环境监测中的应用

本文报道了用被动式个体采样器监测空气小常见污染物ＮＯ２,ＳＯ２．提出了样品测定之前对每种污染物的具体实验要求。对济南市有关场所空气进行了监测。总结了个体采样器的优点。     

Using the polychaete Arenicola marina to determine toxicity and bioaccumulation of PAHS bound to sediments

Transportation system has contributed significantly to the development of human civilization; on the other hand it has an enormous impact on the ambient air quality in several ways. In this paper the air and noise pollution at selected sites along three sections of National Highway was monitored. Pakistan National Highway Authority has started a Highway Improvement program for rehabilitations and maintenance of National highways to improve the traffic flows, and would ultimately improve the air quality along highways. The ambient air quality and noise level was monitored at nine different locations along these sections of highways to quantify the air pollution. The duration of monitoring at individual location was 72 h. The most of the sampling points were near the urban or village population, schools or hospitals, in order to quantify the air pollution at most affected locations along these roads. A database consisting of information regarding the source of emission, local metrology and air quality may be created to assess the profile of air quality in the area.     

Carbon Monoxide Concentration in a Street Canyon of Buenos Aires City (Argentina)

The analysis of three years of 8-h CO concentration values registered in a deep street canyon downtown shows high frequency of values that exceed WHO health protection guidelines. An inverse relationship between opposing percentiles of the distributions of CO concentrations and mean wind speed could be found. Data also showed a variation of mean CO values with prevailing wind direction. The averaged concentration value obtained when the sampler probe is on the leeward side is lower than the obtained when it is on the windward wall. A preliminary explanation of this feature may be related to the advection of polluted air from a high traffic density area nearby.     

Spatio-Temporal Variations of Sulphur Dioxide Patterns with Wind Conditions in Central Taiwan

Sulphur dioxide (SO₂) is one of the main atmospheric pollutants in central Taiwan. This article analyses the SO₂ concentration seasonal variations and spatial distribution using data obtained from ten air quality monitoring stations and the Taiwan Weather Bureau. It reveals that SO₂ concentration is high in winter and low in summer and that high concentration centers are located south of the Taichung coal-fired power plant, the main source of SO₂ emissions in the region.The location of high concentration centers changeswith different prevailing winds. SO₂ variations due towind direction are not unique. During short periods,when meteorological conditions are constant, variationin the pollution sources cause variations in thespatial distribution. This has been deduced byappreciation of Intervention analysis to time seriesof hourly data.     

Inter-Laboratory Comparison of No2 and SO2 Generated by Dynamic Dilution System Under Laboratory Conditions: A Technical Discussion

A workshop on analytical quality control (AQC) of ambient air quality measurement methods for nitrogen dioxide (NO₂) and sulphur dioxide (SO₂) was conducted by Central Pollution Control Board (CPCB) for officials involved in National Ambient Air Quality Monitoring (NAAQM) in India. Concentrations of NO₂ and SO₂ were generated by dynamic dilution system under laboratory conditions at low and high levels and measured using static dilution system and wet chemical methods laid down by CPCB under section 16(2)(h) of the air act 1981. CPCB provided the measured values as reference values for comparing the means obtained by the officials participated from thirteen organizations. A tolerance limit of ±15% of the reference values was specified to accept the results. Generated concentrations, which were unknown to the participants, were measured using gaseous sampling assembly (Envirotech APM 411, New Delhi, India), and wet chemical methods laid down by CPCB i.e. the same methodology which is used by the organizations to generate the data of NO₂ and SO₂ in ambient air. Simultaneously, concentrations were checked by CPCB using automatic analyzers as a check on reference concentration. It is observed that results of automatic analyzers for NO₂ and SO₂ were within a tolerance of ±5% with %RSD below 3. On the other hand, results of most of the participants showed variability in the measurements with %RSD ranging between ±0.8 and ±88.6 and exceedences of means from the tolerance limit with bias ranging between 1.4 and −59%. To check the cause of high variability in the measurements obtained under identical conditions, duplicate sampling was performed by one of the participants for SO₂ at low concentration level. In this study, results of wet chemical methods, automatic analyzers and results of duplicate sampling are analysed statistically to assess the cause of high variability in the measurements. Analysis of t-test and analysis of variance (ANOVA) showed highly significant results for NO₂ and SO₂ at high concentration levels (α 0.05) and for SO₂ at both the levels (α 0.01) respectively indicating some bias is existing either in the sampling or in analytical technique. Duplicate sampling performed to check precision in parallel measurements showed high %RSD indicating the presence of systematic error in sampling technique as the same calibration factor (CF) was used to measure the concentration of duplicate samples. Statistical analysis of flow rates of duplicate sampling showed that the sampling assembly could not maintain the constant flow rate within the ±10% with that measured at the start of the sampling. This resulted in high %RSD and deviation from the reference values for the results of most of the participants, even after accepting ±15% tolerance limit. There is a need to improve and evaluate this gaseous sample collection device under laboratory conditions to generate reliable database of NO₂ and SO₂ in ambient air.     

佛山市高明区环境空气污染物变化分析

根据佛山市高明区2007—2012年环境空气监测数据资料,分析该区近6年来空气污染物的变化趋势和影响因素。结果表明,2007—2012年该区空气污染呈现由单一型污染向复合型污染转变,综合污染指数总体上升,污染物以SO2、PM10为主。SO2、NO2浓度呈逐年增长,PM10则呈平稳状态。三者污染浓度最高值均在每年第4季度出现。该区的SO2浓度主要受工业污染源影响;NO2也受工业影响显著,与机动车数量呈正相关;PM10与烟粉尘排放量呈正相关,与降水量呈负相关。因此,改善该区环境空气应着重从控制工业污染源、扬尘污染、机动车排气污染3大方面开展工作。     

能源结构变化对兰州市大气质量的影响

将2001—2010年的主要能源材料消耗、主要污染物变化及主要行业分布进行了相关性分析,结果表明:兰州市大气4种主要污染物中除烟尘呈下降趋势外,废气总量、SO2、NOx仍呈上升趋势;主要污染源为燃煤,主要污染行业为电力、蒸汽热水产供业;废气和SO2排放总量与燃煤和燃气呈强正相关,而NOx排放只与燃气呈强正相关。建议发挥兰州地域优势,加大以水电供应为主的能源结构调整,对改善当地空气质量有重要价值。