Patterns of atmospheric nitrates,sulfate, and hydrogen chloride in the central Ohio River Valley over a one-year period

A study of the seasonal distribution of gaseous and particulate nitrate, sulfate, and hydrogen chloride in the central Ohio Valley is reported. The Ohio Valley has been identified as a significant source of the precursors to atmospheric acids which may be deposited hundreds of kilometers downwind from the source region. This study was undertaken to provide information on the concentration patterns of several species important in acidic deposition. Filter pack samples were collected for 24 h once each week (with some exceptions) from October 1979 through October 1980. The mean concentrations were: 4.05 μg/m³ sulfate, 3.76 μg/m³ total inorganic nitrate (TIN), 2.11 μg/m³ particulate nitrate (apparent), and 1.65 μg/m³ gaseous nitric acid (apparent). Other recent studies in the Ohio Valley yielded gaseous organic nitrate (PAN) concentrations of 2.3 μg/m³ in the spring and 4.8 μg/m³ in summer. Sulfate concentrations were highest in the summer, and both nitric acid and total inorganic nitrate levels were highest in spring and summer. The HNO₃/TIN ratio was also highest during warm weather. A limited number of samples were analyzed for gaseous hydrogen chloride. The concentration of HCl averaged 0.53 μg/m³ over a 2-month period. On a molar basis, HCl and HNO₃ concentrations were nearly equivalent over the 2-month period, suggesting that more attention should be paid to the role of HCl in atmospheric deposition.     

Development of a personal exposure monitor for two sizes of inhalable particulates

Measurement of personal exposure to ambient level particulate concentrations is often extremely difficult because of a lack of personal exposure monitors capable of collecting measurable quantities within a meaningful sampling period. A new personal exposure monitor for two fractions of inhalable particulates (i.e., the 3–15 μm aerodynamic diameter and the < 3 μm or respirable fraction) has been developed and characterized. This monitor is capable of collecting a sample of each fraction that is quantifiable with ambient concentrations of inhalable/respirable particulates as low as 25 μg/m³ in a 24-h sampling period. Wind tunnel tests have been made on the particulate personal exposure monitor to determine sampling efficiency as a function of relative wind speed and orientation with respect to the sampler.     

基于地面监测数据的2013~2015年长三角地区PM2.5时空特征

近年来,长三角地区灰霾天气持续增多,空气细颗粒物污染问题日益突出。基于2013年1月至2015年5月长三角地区及周边缓冲区内共214个空气质量监测站点PM_2.5逐时监测数据,运用普通克里金插值方法,从年、季、月尺度上分析了PM_2.5的空间分布格局和时间动态变化。结果表明:(1)2 a来,长三角地区PM_2.5浓度空间分布明显呈现整体北部高南部低,局部地区略有突出的分布特征;长三角地区PM_2.5浓度年均值为57.08μg/m³;其中,江苏省PM_2.5的年均值为三省市最高,为65.84μg/m³;其次为上海市,年均值为53.87μg/m³;浙江省PM_2.5的年均值较小,为51.53μg/m³。(2)从季节尺度分析,长三角地区PM_2.5浓度变化表现出冬春季高,夏秋季低的变化趋势;这与区域内冬季风向来源、降水稀少、气象扩散条件差有着密切的关系; (3)长三角地区月浓度变化大致呈U形分布; 12月份PM_2.5浓度最高; 3月份以后, PM_2.5浓度开始呈逐步下降趋势;在5~9月份,区域PM_2.5处于"U"字的谷底,其中6月份夏收时期秸秆焚烧、气象等因素导致PM_2.5浓度有略微升高;进入10月份后迅速攀升,且11、12月份呈现持续升高态势。     

Particulate matter in the Cairo atmosphere. 1. Dustfall and its chemical constituents

Dustfall, sampled in different parts of Cairo, has been analysed for selected constituents in soluble and insoluble fractions. We show that the rate of total particulate deposition over Cairo increased from 27 g/m² · 30 days during 1962 to 57 g/m² · 30 days in 1983; the highest rates of deposition were recorded during winter and spring months, while the maximum concentrations of soluble compounds were found during the summer season. The high concentrations of ammonium and sulphates detected in dustfall over Cairo during summer indicates that atmospheric chemical reactions play an important role in this increase of soluble compounds concentration. The rate of deposition in different districts and the chemical composition indicate that particulate matter in Cairo atmosphere is influenced by urban activities and winds loaded with dust from the industrial areas north and south of the city. Furthermore, i.r. spectroscopic analysis show absorption bands at about 2950, 2920, 2820, 2720, 1720, 1465, 1385, 1300 and 1100 cm⁻¹ which are characteristic bands for aliphatic hydrocarbons, aldehydes, and ketones. The presence of these compounds and the high concentration of tarry matter confirm the role of combustion processes in polluting the atmosphere of Cairo.     

Effect of cigarette smoking on residential NO2 levels

Two studies evaluating the levels and sources of nitrogen dioxide in approximately 90 employee homes in the Richmond area with continuous sampling during the weeks of August 5, 1980, and February 9, 1981, were performed using samplers in the living room, bedroom, kitchen, and outdoors. Additional data were collected concerning appliance usage, heating/cooling plant, ventilation and cigarette smoking. Results were analyzed using BMDP routines. The largest contributor to NO₂ concentration was found to be gas-fired kitchen appliances. The mean kitchen level for homes with gas appliances during the winter study was 188 μg/m³. Excluding participants with gas kitchens, incremental influence due to cigarette smoking was detected. The 7-day, 3-room average level of NO₂ in the homes of nonsmokers and smokers without gas-fired appliances was 12 and 15 μg/m³, respectively, in the summer. The corresponding winter values were 19 and 22 μg/m³. Furthermore, the individual levels of NO₂ in the homes of smokers were generally below both the adjacent outdoor level and the National Ambient Air Quality Standard limit for annual exposure.     

Activity concentrations of 226Ra, 228Ra, 210Pb, 40K and 7Be and their temporal variations in surface air

Activity concentrations of the long-lived natural radionuclides ²²⁶Ra, ²²⁸Ra, ²¹⁰Pb, ⁴⁰K and of ⁷Be in surface air were measured twice monthly at a semi-rural location 10 km north of Munich (FRG) for at least three years. For the time interval 1983–1985, all values were found to be distributed log-normally, with geometric means (in μBq m⁻³) of 1·2 for ²²⁶Ra, 0·5 for ²²⁸Ra, 580 for ²¹⁰Pb, 12 for ⁴⁰K and 3500 for ⁷Be. Reflecting their common origin, the activity concentrations of ²²⁶Ra and ⁴⁰K are correlated with surface air dust concentrations (geometric mean 59 μg m⁻³). Seasonal variations of ²¹⁰Pb and ⁷Be air activity concentrations are established for the time interval 1978–1985.The contribution of local soil activity to the air activity concentrations of these radionuclides and of natural uranium is discussed. Resuspension factors are found to be of the order of 10⁻⁹m⁻¹.     

Indoor radon distribution of subway stations in a Korean major city

The overall survey on indoor radon concentration was conducted at all subway stations in a major city, Daejeon in the central part of Korea. It was quarterly performed from September 2007 to August 2008. The annual arithmetic mean of indoor radon concentration of all the stations was 34.1 ± 14.7 Bq m⁻³, and the range of values was from 9.4 to 98.2 Bq m⁻³. The radon concentrations in groundwater (average 31.0 ± 0.8 Bq m⁻³) were not significantly high in most stations, but the concentration (177.9 ± 2.3 Bq L⁻¹) of one station was over the level of 148 Bq L⁻¹ in drinking water proposed by U.S. EPA. Based on indoor survey results, the approximate average of the annual effective dose by radon inhalation to the employees and passengers were 0.24 mSv y⁻¹, and 0.02 mSv y⁻¹, respectively. Although the effective dose based on the UNSCEAR report was potentially estimated, for more accurate assessment, the additional survey on the influence by indoor radon will be necessary.     

Seasonal variation in outdoor,indoor, and personal air pollution exposures of women using wood stoves in the Tibetan Plateau: Baseline assessment for an energy intervention study

Cooking and heating with coal and biomass is the main source of household air pollution in China and a leading contributor to disease burden. As part of a baseline assessment for a household energy intervention program, we enrolled 205 adult women cooking with biomass fuels in Sichuan, China and measured their 48-h personal exposure to fine particulate matter (PM_2.5) and carbon monoxide (CO) in winter and summer. We also measured the indoor 48-h PM_2.5 concentrations in their homes and conducted outdoor PM_2.5 measurements during 101 (74) days in summer (winter). Indoor concentrations of CO and nitrogen oxides (NO, NO₂) were measured over 48-h in a subset of ~ 80 homes. Women's geometric mean 48-h exposure to PM_2.5 was 80 μg/m³ (95% CI: 74, 87) in summer and twice as high in winter (169 μg/m³ (95% CI: 150, 190), with similar seasonal trends for indoor PM_2.5 concentrations (winter: 252 μg/m³; 95% CI: 215, 295; summer: 101 μg/m³; 95% CI: 91, 112). We found a moderately strong relationship between indoor PM_2.5 and CO (r = 0.60, 95% CI: 0.46, 0.72), and a weak correlation between personal PM_2.5 and CO (r = 0.41, 95% CI: − 0.02, 0.71). NO₂/NO ratios were higher in summer (range: 0.01 to 0.68) than in winter (range: 0 to 0.11), suggesting outdoor formation of NO₂ via reaction of NO with ozone is a more important source of NO₂ than biomass combustion indoors. The predictors of women's personal exposure to PM_2.5 differed by season. In winter, our results show that primary heating with a low-polluting fuel (i.e., electric stove or wood-charcoal) and more frequent kitchen ventilation could reduce personal PM_2.5 exposures. In summer, primary use of a gaseous fuel or electricity for cooking and reducing exposure to outdoor PM_2.5 would likely have the greatest impacts on personal PM_2.5 exposure.     

Health effects of oxidants

Oxidants of significance to human health include ozone, nitrogen dioxide, and peroxyacetylnitrate. All of these compounds are involved in complex photochemical reactions which makes quantification and prediction of their individual health effects difficult. Ozone causes trauma to lung tissues and interferes with enzyme systems in the lungs and other tissues causing a broad range of symptoms. Measurable health impacts can occur at concentrations as low as 390 μg/m³. Acute effects of ozone exposure are reversible at normal urban concentrations (80–120 μg/m³). A special problem of concern, however, is increased susceptibility to infectious diseases contracted through the lungs. Nitrogen dioxide also causes trauma to lung tissues and interferes with enzyme systems. Measurable impacts can occur at concentrations as low as 100 μg/m³, but recovery is rapid and it is not known whether repeated exposures at this level have cumulative effects or predispose the lungs to permanent damage. Chronic exposure of laboratory animals to higher nitrogen dioxide levels can cause emphysema-like conditions and reduction in resistance to respiratory infection. Epidemiological studies of children in houses with gas stoves confirm the finding of reduced resistance to respiratory infection. The U.S. EPA estimates that health effects may occur in young children exposed to concentrations in excess of 280 to 560 μg/m³ one-hour average. These concentrations occur routinely in houses having gas stoves. Peroxyacetylnitrate is a powerful eye irritant in photochemical smog. Other health effects are similar to those of ozone, but less important because of the relatively low concentrations of this pollutant compared to other oxidants.     

Introduction to and experimental conditions during the first year of the GMR chronic inhalation studies of diesel exhaust

A chronic exposure study was initiated to determine the effects of diesel exhaust on the health of experimental animals. For this purpose, test atmospheres of clean air (control) or freshly diluted diesel exhaust at concentrations of 250, 750, and 1500 μg/m³ were supplied to four 12.6 m³ inhalation chambers which housed rats and guinea pigs. Diesel aerosol size and concentration, as well as chamber temperature and relative humidity, were continually monitored and controlled to maintain the exposure dose levels and an environment of 22±2°C and 50%±20% relative humidity. The concentrations of CO and NO_x were found to be 5.8±1.0 mg/m³ and 7.9±1.0 mg/m³ above ambient in the chamber containing 1500 μg/m³ of particulate. Animals were supplied from the chambers, on a random basis, for both intramural and extramural studies throughout the exposure period. The experiment ran uninterrupted for over twelve months with mean diesel particle mass concentrations within 2% of the target values.     

Aluminum, iron, and lead content of respirable particulate samples from a personal monitoring study

Samples of respirable particulate matter collected during a personal monitoring study in Topeka, KS, were analyzed for iron, aluminum, and lead content. The sampling protocol and instrumentation are described in detail. Lead indoor concentrations (median = 79 ng/m³) were found to be less than both personal (median = 112 ng/m³) and outdoor lead concentrations (median = 106 ng/m³). The indoor, outdoor, and personal levels of iron and aluminum were not significantly different. In addition, it was determined that outdoor respirable particulate mass does not correlate well with the personal or indoor metal concentrations, and that the amount of time spent in motor vehicles is a relatively good indicator of lead exposures. The relationships between indoor, outdoor, and personal lead are discussed in greater detail, with references to supporting evidence from other studies.     

Investigation of volatile organic compounds and phthalates present in the cabin air of used private cars

The presence of selected volatile organic compounds (VOCs) including aromatic, aliphatic compounds and low molecular weight carbonyls, and a target set of phthalates were investigated in the interior of 23 used private cars during the summer and winter. VOC concentrations often exceeded levels typically found in residential indoor air, e.g. benzene concentrations reached values of up to 149.1 µg m^− 3. Overall concentrations were 40% higher in summer, with temperatures inside the cars reaching up to 70 °C. The most frequently detected phthalates were di-n-butyl-phthalate and bis-(2-ethylhexyl) phthalate in concentrations ranging from 196 to 3656 ng m^− 3.     

Changes in indoor climate after tightening of apartments

The effect of reduced air infiltration rate caused by energy-saving measures has been studied by comparing the indoor climate in 25 sealed apartments with the conditions in 25 unsealed apartments in four seasonal periods. The indoor temperature in bedrooms during February and March was 19.3 °C in sealed apartments and 17.8 °C in unsealed apartments, and the occupants in the sealed apartments correspondingly complained less frequently of draught problems during the winter. When the frequency of window opening was at its minimum (February–March), there was a higher indoor humidity in sealed compared with unsealed apartments, and this probably accounts for an increased occurrence of house-dust mites in dust from the sealed apartments during the winter. Also in February–March there was a slight increase in the concentration of suspended particulate matter in sealed apartments. Considering health effects of a reduced air infiltration rate, it can be predicted that the increased indoor air humidity will indirectly increase the frequency and severity of house-dust mite allergy in the population.     

A method to derive the relationship between the annual and short-term air quality limits—Analysis using the WHO Air Quality Guidelines for health protection

The World Health Organization (WHO) Air Quality Guidelines (AQG) were launched in 2006, but gaps remain in evidence on health impacts and relationships between short-term and annual AQG needed for health protection. We tested whether relationships between WHO short-term and annual AQG for particulates (PM₁₀ and PM_2.5) and nitrogen dioxide (NO₂) are concordant worldwide and derived the annual limits for sulfur dioxide (SO₂) and ozone (O₃) based on the short-term AQG. We obtained air pollutant data over seven years (2004–2010) in seven cities from Asia-Pacific, North America and Europe. Based on probability distribution concept using maximum as the short-term limit and arithmetic mean as the annual limit, we developed a new method to derive limit value one from another in each paired limits for each pollutant with capability to account for allowable exceedances. We averaged the limit derived each year for each city, then used meta-analysis to pool the limit values in all cities. Pooled mean short-term limit for NO₂ (140.5 μg/m³ [130.6–150.4]) was significantly lower than the WHO AQG of 200 μg/m³ while for PM₁₀ (46.4 μg/m³ [95CI:42.1–50.7]) and PM_2.5 (28.6 μg/m³ [24.5–32.6]) were not significantly different from the WHO AQG of 50 and 25 μg/m³ respectively. Pooled mean annual limits for SO₂ and O₃ were 4.6 μg/m³ [3.7–5.5] and 27.0 μg/m³ [21.7–32.2] respectively. Results were robust in various sensitivity analyses. The distribution relationships between the current WHO short-term and annual AQG are supported by empirical data from seven cities for PM₁₀ and PM_2.5, but not for NO₂. The short-term AQG for NO₂ should be lowered for concordance with the selected annual AQG for health protection.     

上海崇明岛近三年PM_(2.5)浓度变化特征与气象条件的关系

利用2011年1月~2014年2月上海崇明岛地区颗粒物(PM_(2.5)、PM_(10))的连续监测资料,研究了PM_(2.5)总体分布、季节变化、日变化及浓度频率分布规律,初步分析了逆温、相对湿度、风向风速等气象要素对颗粒物浓度的影响。结果表明:2011~2013年该地区PM_(2.5)平均值分别为24.7,33.6和28.3μg/m~3,均低于PM2.5的年平均浓度限值35μg/m~3,细粒子污染程度较轻。PM_(2.5)浓度日变化幅度不大,呈微弱的单峰型分布,9∶00左右达到一天中的最大值,15∶00左右达到最小值。PM_(2.5)浓度的季节分布特征明显,呈现出冬季春季秋季夏季,一般情况下5月份PM_(2.5)月均浓度值最高,8月份浓度最低。PM_(2.5)日平均浓度有57.9%达到国家空气质量一级标准,有93.4%达到国家空气质量二级标准,超标率为6.6%。对PM_(2.5)与各气象要素进行分析后发现:PM_(2.5)质量浓度在逆温层结稳定、风速小、高湿以及近地面盛行西北到西风这样的静稳天气条件配合高空西北方向上的外来污染物输送,容易造成高浓度的PM_(2.5)污染。     

Particle and solution phase depth distributions of transuranics and 55Fe in the North Pacific

In situ large volume filtration and chemisorption techniques were used to collect samples from the North Pacific for radiochemical analyses of fallout transuranics and ⁵⁵Fe in filterable and filtered phases. The data cover several locations for surface collections and a detailed depth profile north of Hawaii at 30°N. The observed partition of these nuclides between suspended particulate and filtered phases is directly linked to the rates at which they are moved downward through the water column in association with sinking particles. Particulate phases in open ocean surface waters contain higher Pu (12–35%) than subsurface particulates (which average about 6%). ²⁴¹Am was found to exhibit much stronger particle association—typically close to 50% in both surface and subsurface waters—in accord with its known greater particle reactivity. In the high Pu deep water layer, particle associated Pu dropped to close to 1% of total Pu concentration. Together with a correlated increase in the proportion of oxidized Pu in this layer close to the sediment-water interface, this is taken as clear evidence of remobilization Pu from particles at, or near to, the interface. ⁵⁵Fe distributions on filtered particulates indicate a much deeper depth distribution relative to the transuranics. This may reflect both a higher particle association reactivity in respect to scavenging and a longer exposure history to scavenging (especially relative to ²⁴¹Am—produced by in situ decay).     

Cocaine and cannabinoids in the atmosphere of Northern Europe cities,comparison with Southern Europe and wastewater analysis

This study reports the first investigation of atmospheric illicit drug concentrations in Northern Europe using measurements of cocaine and cannabinoids in Amsterdam, London and Stockholm. Further, these measurements were compared to those made in Rome to explore the geographical and inter-city variability. Co-located measurements of atmospheric particulate mass and PAHs were used to help describe and interpret the illicit drug measurements with respect to atmospheric dispersion. Cocaine concentrations ranged from 0.03 to 0.14 ng/m³ in Amsterdam, from 0.02 to 0.33 ng/m³ in London and were below quantification limit (3 pg/m³) in Stockholm. Cannabinol was the only cannabinoid molecule detected in the three cities. During this campaign, London reported the highest concentrations of cocaine and meaningful differences were detected between the urban background and city centre London sites. Mean cocaine concentrations measured in Amsterdam during March 2011 were also compared with those measured simultaneously in eight Italian cities. The cocaine concentration in Amsterdam was comparable to that measured at an urban background in Milan and at a densely populated site in Florence. Although correlating atmospheric concentrations directly with drug prevalence is not possible using current data, links between concentrations of cocaine and estimates of abuse prevalence assessed by the more routinely used wastewater analysis were also examined. A statistically significant correlation was found between the two sets of data (R² = 0.66; p = 0.00131). Results confirmed that meteorology, population rate and habits of consumption influence the atmospheric concentrations of drugs. If these confounding factors were better controlled for, the techniques described here could became an easy and cost effective tool to index the impact of cocaine abuse in the area; especially where local hot spots need to be identified.     

Dynamic model for radionuclide uptake in lichen

Samples of atmospheric particulate material and terrestrial plants, including lichens, were collected in New Brunswick, Canada between 1980 and 1983 and analyzed for a wide range of artificial and naturally-occuring radionuclides, including fission products (¹⁴¹Ce, ¹⁴⁴Ce, ¹⁰³Ru, ¹⁰⁶Ru, ⁹⁵Zr and ¹³⁷Cs) derived from the 16 October 1980 Chinese nuclear test. Activity ratios of some of the short-lived fission products in air particulates and lichens are in reasonable agreement with those predicted from fission product yields for nuclear weapons tests, indicating that only minor fractionation occurred for these radionuclides during their transport through air particulate and lichen environmental phases. The ⁷Be inventories measured in a suite of lichen (Cladonia rangiferina) samples were used to calibrate each lichen plant for its collection efficiency for atmospheric particulates and fallout radioactivity.A lichen model has been developed to predict lichen inventories of radioactivity for different lichen growth functions and bio-elimination rates. Assuming that lichen growth results in a linear increase in surface area with time, the experimental results yield biological residence times of 1–2 years for ²¹⁰Pb and Pu and 5–8 years for ¹³⁷Cs. The more efficient retention of ¹³⁷Cs is probably due to its physiological uptake in lichen plants as a proxy for potassium, as evidenced by an observed, inverse relationship between ¹³⁷Cs and ⁴⁰K activities in lichen.     

湖北东湖、梁子湖和洪湖颗粒物吸收光谱特征分析

通过对2007年9月底和10月初湖北东湖、梁子湖、洪湖水体中悬浮颗粒物的吸收系数进行研究,系统分析了3个湖泊水体中颗粒物吸收系数变化规律及影响因素。结果表明：总颗粒物吸收表现出明显浮游植物吸收特征,反映颗粒物中浮游植物贡献比较高;东湖和梁子湖吸收系数显著大于洪湖,表明东湖和梁子湖水下光场条件不如洪湖。武汉东湖各点颗粒物吸收系数变化不大,而梁子湖和洪湖各点则存在较大空间差异。3个湖泊非藻类颗粒物吸收光谱谱型一致,随波长增加大致按指数规律衰减。武汉东湖、梁子湖、洪湖指数函数斜率平均值分别为12.31±0.32 μm-1、1196±084 μm-1、1198±168 μm-1。浮游植物特征波长的吸收系数与浮游植物色素浓度具有显著性正相关,可以通过色素浓度测定反推浮游植物吸收系数。总颗粒物、非藻类颗粒物吸收系数与总悬浮物、有机颗粒物、无机颗粒物均存在显著性正相关。浮游植物吸收系数与有机颗粒物也有很好的线性相关,证明有机颗粒物主要以浮游植物为主。     

Chemical characteristics of precipitation and wet deposition of major ions in Liaozhong County of Liaoning Province,Northeast China

The chemical characteristics of precipitation were analyzed based on the chemical composition of principal ionic within acid rain（from February 2007 to January 2008）of Liaozhong Meteorological Station located in Malong Village in Liaozhong County of Northeast China,meteorological conditions on the corresponding period ground,and variation of several air pollutants concentration.The results indicated that:（1）The precipitation average pH value of all samples was4.76;the frequency of acid rain during the observation period was 70.7%;the frequency was 82.8%in summer and autumn.（2）In the chemical composition of precipitation,the primary anions were SO₄^2-and NO₃^-;the primary cations were NH₄⁺and Ca²⁺.（3）All concentration of anions was higher in summer and winter,but relatively low in spring and autumn.This showed that the relationship between regional rainfall acidification and pollution was not significant.（4）Rainwater acidity and nearly floor gaseous pollution concentration were different from each other,and pH and NO_x,CO,NO₂ and O₃concentrations showed significant negative correlation,but was not obvious with SO₂ concentration.However,the pH and alkaline pollutants,such as particulate,was positively correlative.