博罗县环境空气质量变化趋势浅析

本文以博罗县2005—2011年间的环境空气监测数据为依据,采用空气污染综合指数法评价大气环境质量,并运用Spearman秩相关系数预测未来发展趋势。结果表明：博罗县环境空气质量为优,主要污染物为二氧化氮,年日平均浓度呈上升趋势,不显著。     

Assessment and management of air quality for an opencast coal mining area

A study for the assessment and management of the air quality was carried out at Lakhanpur area of Ib Valley Coalfield in Orissa state in India. The 24-h average concentrations of total suspended particulate (TSP) matter, respirable particulate matter (PM10), sulphur dioxide (SO2) and oxides of nitrogen (NOx) were monitored during 1 year period. Samplings were done at a regular interval through out the year at 13 monitoring stations in the residential areas and four monitoring stations in the mining/industrial areas. The 24-hr average TSP and PM10 concentrations ranged from 338.8 to 799.8 microg m(-3) and 102.5-425.6 microg m(-3) for industrial area, and 72.3-497.1 microg m(-3) and 40.8-171.9 microg m(-3) for residential area, respectively. During the study period 24-hr and annual average TSP and PM10 concentrations exceeded the respective standards set in the national ambient air quality standard (NAAQS) protocol at most residential and industrial areas. However, 24-hr and annual average concentrations of SO2 and NOx were well within the prescribed limit of NAAQS both in the residential and industrial areas. The annual and 24-hr average concentrations varied from 23.3 to 36.8 microg m(-3) and 16.0-55.2 microg m(-3) for SO2 and 23.9-41.9 microg m(-3) and 19.0-58.1 microg m(-3) for NOx, respectively. The temporal variations of TSP and PM10 fitted polynomial trend with an average correlation coefficient (R2) of 0.77 (+/-0.17) for TSP and 0.85 (+/-0.10) for PM10. On average the PM10 in the ambient air of the mining area constituted 31.94 (+/-1.76)% of the TSP. The linear regression correlation coefficient (R2) between TSP with PM10 and NOx with SO2 was 0.86 (+/-0.12) and 0.57 (+/-0.20), respectively. Maximal concentrations of TSP and PM10 occurred within the mining site based on the kriging technique. A management strategy is formulated for effective control of air pollution at source and other mitigative measures recommended including implementation of green belts around the sensitive areas where the concentration of air pollutants exceeded the standard limit.     

Determination of VOC source signature of vehicle exhaust in a traffic tunnel

This study describes the methodology used to obtain the volatile organic compound (VOC) source signature of vehicle exhaust. To accomplish this, C(2)-C(9) VOCs were measured in a traffic tunnel located in Seoul, South Korea. The effect of VOC concentrations from the outside ambient air was considered in the determination of the source signature. To examine the effects of ambient air on VOC concentrations inside the tunnel, the ratio of propane to the total VOC concentrations was compared between the entrance and middle sites in the tunnel. Propane was used as a standard not only because of its insignificant contribution to vehicle exhaust gas, but also the fact that propane is the most abundant VOC in the atmosphere of Seoul. The ratio of propane to the total VOC concentrations was higher at the entrance site than at the middle location by, on average, 60%. This suggests that ambient air affects the inside tunnel air to a greater extent at the entrance site as compared to the middle site. The contribution of ambient air to the air inside the tunnel at the entrance location varied from 30% to 67%, with an average of 55%. This is 1.5 times higher than the value measured at the middle location, which ranged from 20% to 48%, with an average of 36%. This shows that ambient air substantially affects the inside air of the tunnel. Excluding the effects of ambient air on the air inside the tunnel can provide an improved chemical composition for vehicle exhaust using tunnel measurements. We believe that the concentration difference between the two sites within the tunnel provides a more accurate chemical composition of vehicle exhaust as compared to that obtained from a measurement taken at only one point inside the tunnel.     

Ambient monitoring of asbestos in selected Italian living areas

This paper presents the results of an intensive monitoring activity of the particulate, fall-out and soil of selected living areas in Italy with the aim to detect the asbestos concentration in air and subsequent risk of exposure for the population in ambient living environments, and to assess the nature of the other mineral phases composing the particulate matrix. Some areas were sorted out because of the presence of asbestos containing materials on site whereas others were used as blank spots in the attempt to detect the background environmental concentration of asbestos in air. Because the concentration of asbestos in ambient environments is presumably very low, and it is well known that conventional low–medium flow sampling systems with filters of small diameter (25 mm) may collect only a very small fraction of particulate over a short period, for the first time here, an intense monitoring activity was conducted with a high flow sampling system. The high flow system requires the use of large cellulose filters with the advantage that, increasing the amount of collected dust, the probability to collect asbestos fibers increases. Both the protocol of monitoring and analysis are novel and prompted by the need to increase the sensitivity towards the small number of expected fibers. With this goal, the collection of fall-out samples (the particulate falling into a collector filled with distilled water during the monitoring shift) and soil samples was also accomplished. The analytical protocol of the matrix particulate included preliminary X-ray powder diffraction (XRPD), optical microscopy and quantitative electron microscopy (SEM and TEM). Correlations with climatic trends and PM10 concentration data were also attempted.The surprising outcome of this work is that, despite the nature of the investigated site, the amount of dispersed asbestos fibers is very low and invariably lower than the theoretical method detection limits of the SEM and TEM techniques for identification and counting of asbestos fibers. The results are compared to the literature data worldwide and an updated model for asbestos fibers dispersion in ambient environments is proposed.     

An Approach for Evaluating the Effectiveness of Various Ozone Air Quality Standards for Protecting Trees

We demonstrate an approach for evaluating the level of protection attained using a variety of forms and levels of past, current, and proposed Air Quality Standards (AQSs). The U.S. Clean Air Act requires the establishment of ambient air quality standards to protect health and public welfare. However, determination of attainment of these standards is based on ambient pollutant concentrations rather than prevention of adverse effects. To determine if a given AQS protected against adverse effects on vegetation, hourly ozone concentrations were adjusted to create exposure levels that “just attain” a given standard. These exposures were used in combination with a physiologically-based tree growth model to account for the interactions of climate and ozone. In the evaluation, we used ozone concentrations from two 6-year time periods from the San Bernardino Mountains in California. There were clear differences in the level of vegetation protection achieved with the various AQSs. Based on modeled plant growth, the most effective standards were the California 8-hr average maximum of 70 ppb and a seasonal, cumulative, concentration-weighted index (SUM06), which if attained, resulted in annual growth reductions of 1% or less. Least effective was the 1-hr maximum of 120 ppb which resulted in a 7% annual reduction. We conclude that combining climate, exposure scenarios, and a process-based plant growth simulator was a useful approach for evaluating effectiveness of current or proposed air quality standards, or evaluating the form and/or level of a standard based on preventing adverse growth effects.     

山东省辖城市空气自动监测网运行监控及信息管理系统

研制了山东省环境空气自动监测网络运行监控及信息管理系统,实现了山东省全部省辖市所有点位环境空气自动监测统一数据实时采集与多级多目标传输,全过程跟踪的质量控制与保证,全省统一数据确认、在线信息化管理。     

长沙市城区典型交通路口PM_(10)和PM_(2.5)污染特征研究

利用车载环境空气质量监测系统对长沙市城区典型交通路口的近地面空气质量进行了实时监测。结果表明,在监测时段(14∶00~20∶00)内,该监测点环境空气中PM10的小时质量浓度范围在0.097~0.222mg/m3之间,平均值0.163mg/m3;PM2.5的小时质量浓度范围在0.050~0.158mg/m3之间,平均值0.103mg/m3。PM2.5/PM10比值在48.1%~76.6%之间,平均值62.4%。PM10与PM2.5质量浓度在星期一相对较低,星期二有所升高,星期三至周末总体上保持基本稳定。在监测时段PM10与PM2.5小时质量浓度呈现先降后升的变化规律,即14∶00~15∶00,PM10与PM2.5质量浓度相对较高,16∶00左右降至最低,从17∶00开始逐渐升高,20∶00达到峰值。PM10和PM2.5的质量浓度变化与车流量和车速密切相关,温度、相对湿度和风速等气象因素对PM10和PM2.5质量浓度的变化影响也较显著。     

Ground-level ozone in the Pearl River Delta and the roles of VOC and NO(x) in its production

In many regions of China, very rapid economic growth has been accompanied by air pollution caused by vehicle emissions. In one of these regions, the Pearl River Delta, the variations of ground-level ozone and its precursors were investigated. Overall, the ambient concentrations of NO(2) increased quickly between 1995 and 1996, but then slightly decreased due to stringent nitrogen oxide (NO(x)) emission controls. Nonetheless, ambient NO(2) levels in the Pearl River Delta remained high. The regional average concentrations of volatile organic compounds (VOCs) were 290 ppbC in summer and 190 ppbC in autumn. Local emissions and long-distance transportation of pollutants play important roles in the regional distribution of VOCs. Ambient O(3) production is significant in urban areas and also downwind of cities. The relative incremental reactivities (RIRs), determined by an observation-based model, showed that ground-level ozone formation in the Guangzhou urban area is generally limited by the concentrations of VOCs, but there are also measurable impacts of NO(x).     

Measuring neighbourhood air pollution: the case of Seattle's international district

Current US regulatory air quality monitoring networks measure ambient levels of pollutants and cannot capture the effects of mobile sources at the micro-scale. Despite the fact that overall air quality has been getting better, more vulnerable populations (children, the elderly, minorities and the poor) continue to suffer from traffic-related air pollution. As development intensifies in urban areas, more people are exposed to road-related air pollution. However, the only consideration given to air quality, if any, is based on ambient measures. This paper uses an inexpensive, portable Particle Soot Absorption Photometer (PSAP) to measure Black Carbon (BC) emissions, a surrogate for diesel fuels emissions, in Seattle's International District. With the aid of a GPS receiver, street-level BC data were geocoded in real space-time. It was found that pollution levels differed substantially across the study area. The results show the need for street-level air pollution monitoring, revisions in current land use and transportation policies, and air quality planning practice.     

A human health assessment of hazardous air pollutants in Portland, OR

Ambient air samples collected from five monitoring sites in Portland, OR during July 1999 to August 2000 were analyzed for 43 hazardous air pollutants (HAP). HAP concentrations were compared to carcinogenic and non-carcinogenic benchmark levels. Carcinogenic benchmark concentrations were set at a risk level of one-in-one-million (1x10(-6)). Hazard ratios of 1.0 were used when comparing HAP concentrations to non-carcinogenic benchmarks. Emission sources (point, area, and mobile) were identified and a cumulative cancer risk and total hazard index were calculated for HAPs exceeding these health benchmark levels. Seventeen HAPs exceeded a cancer risk level of 1x10(-6) at all five monitoring sites. Nineteen HAPs exceeded this level at one or more site. Carbon tetrachloride, 1,3-butadiene, formaldehyde, and 1,1,2,2-tetrachloroethane contributed more than 50% to the upper-bound lifetime cumulative cancer risk of 2.47x10(-4). Acrolein was the only non-carcinogenic HAP with hazard ratios that exceeded 1.0 at all five sites. Mobile sources contributed the greatest percentage (68%) of HAP emissions. Additional monitoring and health assessments for HAPs in Portland, OR are warranted, including addressing issues that may have overestimated or underestimated risks in this study. Abatement strategies for HAPs that exceeded health benchmarks should be implemented to reduce potential adverse health risks.     

Predicting soil fumigant air concentrations under regional and diverse agronomic conditions

SOFEA (SOil Fumigant Exposure Assessment system; Dow AgroSciences, Indianapolis, IN) is a new stochastic numerical modeling tool for evaluating and managing human inhalation exposure potential associated with the use of soil fumigants. SOFEA calculates fumigant concentrations in air arising from volatility losses from treated fields for large agricultural regions using multiple transient source terms (treated fields), geographical information systems (GIS) information, agronomic specific variables, user-specified buffer zones, and field reentry intervals. A modified version of the USEPA Industrial Source Complex Short Term model (ISCST3) is used for air dispersion calculations. Weather information, field size, application date, application rate, application type, soil incorporation depth, pesticide degradation rates in air, tarp presence, field retreatment, and other sensitive parameters are varied stochastically using Monte Carlo techniques to mimic region and crop specific agronomic practices. Regional land cover, elevation, and population information can be used to refine source placement (treated fields), dispersion calculations, and risk assessments. This paper describes the technical algorithms of SOFEA and offers comparisons of simulation predictions for the soil fumigant 1,3-dichloropropene (1,3-D) to actual regional air monitoring measurements from Kern, California. Comparison of simulation results to daily air monitoring observations is remarkable over the entire concentration distribution (average percent deviation of 44% and model efficiency of 0.98), especially considering numerous inputs such as meteorological conditions for SOFEA were unavailable and approximated by neighboring regions. Both current and anticipated and/or forecasted fumigant scenarios can be simulated using SOFEA to provide risk managers and product stewards the necessary information to make sound regulatory decisions regarding the use of soil fumigants in agriculture.     

大连市环境空气中PM_（2.5）含碳组分浓度特征研究

2013年9~12月对大连市环境空气中的PM2.5、有机碳和元素碳进行连续监测。研究结果表明,有机碳约占PM2.5质量的14.0%,元素碳约占6.9%,有机碳和元素碳的总质量约占PM2.5的21%。一半以上的天数有机碳与元素碳比值超过2.0,说明大连存在二次污染。有机碳与元素碳具有显著的正相关性,相关系数约为0.93,表明有机碳和元素碳可能有相同的污染来源。较大降水能有效降低PM2.5、有机碳和元素碳的浓度,风速与PM2.5、有机碳和元素碳的浓度呈负相关,雾霾天气时,有机碳和元素碳的浓度明显增加。     

Blowing Smoke in Yellowstone: Air Quality Impacts of Oversnow Motorized Recreation in the Park

Snowmobile use in Yellowstone National Park has been shown to impact air quality, with implications for the safety and welfare of Park staff and other Park resource values. Localized impacts have been documented at several high-use sites in the Park, but the broader spatial variability of snowmobile emissions and air quality was not understood. Measurements of 87 volatile organic compounds (VOCs) were made for ambient air sampled across the Park and West Yellowstone, Montana, during 2 days of the 2002–2003 winter use season, 1 year before the implementation of a new snowmobile policy. The data were compared with similar data from pristine West Coast sites at similar latitudes. Backward trajectories of local air masses, alkyl nitrate-parent alkane ratios, and atmospheric soundings were used to identify the VOC sources and assess their impact. Different oversnow vehicle types used in the Park were sampled to determine their relative influence on air mass pollutant composition. VOCs were of local origin and demonstrated strong spatiotemporal variability that is primarily influenced by levels of snowmobile traffic on given road segments at different times of day. High levels of snowmobile traffic in and around West Yellowstone produced consistently high levels of benzene, toluene, and carbon monoxide.     

Temporal‐spatial variations of air pollutants in Lanzhou,Gansu Province,China, during the spring–summer periods, 2014–2016

In this article, we analyzed the mass concentrations of particulate matter 2.5 micrometers (µm) or less in size (PM_2.5), particulate matter 10 µm or less in size (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), and ozone (O₃) in Lanzhou, the capital of Gansu province, China. We analyzed monitoring data collected from five air quality monitoring stations during the spring–summer period from 2014 to 2016. Our comparison of contaminant concentrations and average diurnal, daily, monthly, and annual concentrations revealed that the average concentrations of PM_2.5 and PM₁₀ amounted to 128.57 and 46.4 micrograms per cubic meters (µg/m³), respectively, exceeding the Chinese National Ambient Air Quality Standard (NAAQS). We used the Pearson correlation coefficient to establish connections between particulate matter and gaseous pollutants. The results show significant differences in the concentration levels of airborne pollutants. The Pearson correlation coefficient between PM_2.5 and PM₁₀ had the highest coefficient of r = 0.842. A correlation between the two particulate matter sizes (PM_2.5 and PM₁₀) and SO₂ was PM_2.5 and SO₂ r = 0.313; PM₁₀ and SO₂ r = 0.279; and CO and the two particulate matter sizes, PM_2.5 and CO r = 0.304; and PM₁₀ and CO r = 0.203. The average monthly ratio for the study months of PM_2.5 to PM₁₀ was 0.361. In addition, we used the hybrid single particle Lagrangian integrated trajectory model for tracking sources and pathways of the air pollutants in Lanzhou.     

环境空气监测子站气象仪器性能状况比对研究

气象监测是环境空气质量监测的重要组成部分,在环境空气质量精细化管理中发挥着重要作用.气象部门通常采用集中送检或现场校准的方式对气象仪器性能状况进行检查,但环保部门对监测子站气象仪器的相关性能检查还处于空白状态.结合国家环境空气质量自动监测网管理现状,研究采用现场比对方式进行气象仪器性能评估.试验过程中,温度、气压比对数...     

Passive monitoring of nitrogen dioxide in urban air: a case study of Durban metropolis, South Africa

To devise and implement strategies to manage the quality of urban air, a metropolis needs air pollution data on which an air quality management plan can be formulated. Although air pollutants can come from several sources, many reports suggest that nitrogen dioxide from motor vehicle emissions is the major contributor to air pollution in cities. Since vehicles stop or move slowly through traffic intersections, concentrations of nitrogen dioxide (NO(2)) are expected to be relatively high at these sites. Inexpensive Ogawa passive samplers were placed at selected traffic intersections in the Durban Metropolis to trap the NO(2) which was then analysed by a sensitive laboratory-based method. The data obtained by this method was compared with data from sophisticated system comprising an active sampler cum on-line chemiluminescence detector. The sampling was done over a twelve month period to cover all seasons. Statistical analysis of the data showed that there was no significant difference between the means for the two methods. This study has established that an Ogawa passive sampler may be used as an economical and reliable collector for NO(2) in ambient air under varying climatic conditions. Further, the analysis method using a UV-Visible spectrophotometer was sensitive enough to detect NO(2) at the 10-20 ppb level. The cost of the method should be well within the budgets of most municipalities and it would motivate them to develop policies to alleviate traffic congestion.     

Analysis of Roadside Inhalable Particulate Matter (PM10) in Major Korean Cities

A data analysis of three major Korean cities was conducted to assess roadside inhalable particulate matter 10 μm or smaller in aerodynamic diameter (PM₁₀), including temporal and meteorological variations, over a recent period of 4 to 6 years. The yearly roadside PM₁₀ concentrations presented a well-defined increasing trend or no trend depending on the roadside monitoring station. Most mean values exceeded or approximated the Korean standard of 70 μg/m³ per year for PM₁₀. A representative roadside diurnal trend was characterized by a distinct morning maximum. In most cases, the Sunday roadside concentrations were similar to or somewhat lower than the weekday concentrations, and the PM₁₀ concentrations presented a well-defined seasonal variation, with the maximum concentration in March. The monthly maximum concentrations observed in March were most likely attributable to Asian dust storms. In two metropolitan cities (Seoul and Busan), the frequency of days with roadside PM₁₀ concentrations exceeding the standard of 150μg/m³ per 24 h was much lower for the roadside monitoring stations than for the residential monitoring station, whereas in the third city (Daegu), this result was reversed. Interestingly, the average maximum concentrations observed for the roadside sites in Seoul and Busan during March were higher than those for the residential sites, suggesting that the roadside concentrations responded more to the dust storms than the residential areas. The relationship between the pollutant concentrations and five important meteorological parameters (solar radiation, wind speed, air temperature, relative humidity, and precipitation) showed that the number and type of meteorological variables included in the equations varied according to the monitoring station or season. Finally, the current results confirmed that attention should be given to the PM₁₀ exposure of residents living near roadways.     

Health benefits due to reductions of CO levels

A method is presented by which an upper limit of the adverse health effect of existing ambient CO concentrations on the U. S. population can be estimated. The method is based upon estimating the primary human physiological response to CO concentrations (COHb%) for the population in terms of person-hour-COHb>1.5% resulting from the time exposure of the population to CO concentrations in excess of the federally designated ambient air quality standard. The estimates of person-hour-COHb>1.5% are for exposures only to ambient CO concentrations and do not take into account the additional CO exposure for people who smoke or have occupational exposures.We estimate that there were up to 30.9×10⁹ person-hour-COHb>1.5% in 1973 due to ambient concentrations in excess of the ambient 8-hour CO standard, with approximately 5×10⁹ person-hour-COHb>1.5% occurring West of the Continental Divide and 25.9>10⁹ person-hour-COHb>1.5% occuring East of the Continental Divide; of these 21.3×10⁹ personhour-COHb>1.5% occurred in New York City. It was also estimated that a 60% reduction in 1973 ambient concentrations of CO (corresponding to an automotive emmision standard of less than 15 g/mile) would be needed to reduce to zero the person-hour-COHb>1.5%. The maximum estimated effects on the U.S. population of increases in ambient CO concentration above 1973 levels are also presented.     

Experimental study of benzene,toluene, ethylbenzene,and xylene (BTEX) contributions in the air pollution of Tehran,Iran

Urbanization and development are associated with air pollution, including emissions of volatile organic compounds (VOCs) such as benzene, toluene, ethylbenzene, and xylene (BTEX). For this study, we measured and investigated the outdoor concentrations of BTEX in Tehran, Iran. National Institute for Occupational Safety and Health (NIOSH, 1996) methods were applied to measure the concentrations of BTEX in winter and spring of 2015 at 46 air monitoring stations. BETX concentrations were also measured at 19 monitoring stations in June and July of 2003. In 2003, BTEX compound pollutants were observed at greater concentration in the eastern, central, and southern zones of Tehran than in other zones. The average concentrations of the BTEX compounds were 238 parts per billion (ppb), 130 ppb, 69 ppb, and 118 ppb, respectively, for benzene, toluene, ethylbenzene, and xylene. The benzene to toluene (B/T) ratios ranged from 0.8 to 3.2, which indicated that the gasoline used in the city was of poor quality at that time. In 2015, the BTEX concentrations in District 19 (south of Tehran) were higher than in the eastern and central regions, which included restricted “traffic zones” and the extensive development of public transportation systems. In the restricted traffic zones, only public vehicles, such as buses, taxis, ambulances, etc., and other authorized vehicles are allowed to operate. By ameliorating the quality of gasoline, encouraging the use of late model private cars, and development of subway and public transportation during the years between 2003 and 2015, the BTEX concentrations have fallen to levels that comply with Iran's air quality standards. The 2015 measurements revealed that the average concentrations of the BTEX compounds were 5.3, 9.2, 1.5, and 2.6 ppb, respectively. The B/T ratio fluctuated from 0.39 to 0.76, demonstrating the remarkable role that vehicle traffic plays in BTEX pollution.     

泸州市环境空气质量状况及评价

根据泸州市１９９４年－１９９８年环境大气监测数据,对全市环境大气质量,状况进行分析和评价。