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The cement industry is considered to be an important anthropogenic thallium (Tl) emission source, and yet few reports have been released concerning the fate of Tl during cement production and the emissions of Tl from cement plants (CPs). In this study, three precalciner CPs in the Guizhou province in southwest China were systematically investigated, with all input/output solid materials collected and analyzed. Despite using different raw materials, strong Tl enrichment during the clinker production was observed in all three CPs, with enrichment factors ranging from 85 to 148. Tl concentrations in limestone and most other raw materials were low (0.032–4.163 mg kg−1), but they were 100–700 times higher in the raw meal and kiln tail dust due to circulation and enrichment inside the system. Only a low percentage (3–8 %) of Tl exited the system via the clinker and stack emissions. Atmospheric emission factors of Tl from the three CPs ranged from 0.168 to 0.980 mg Tl tonne−1 clinker, with an average of 0.674 mg Tl tonne−1 clinker. Annual atmospheric Tl emissions from all the CPs were estimated to be 54 kg·yr−1 in Guizhou province and 964 kg·yr−1 over all of China in 2018. Shuttling kiln tail dust may reduce the Tl enrichment during clinker production, and Tl recycled from this material may have commercial value.

Cities of Beijing–Tianjin–Hebei (BTH) and its surrounding areas are a focus of air pollution control in China. This study analyzed the emission characteristics of industrial pollution sources within these cities from the perspective of big data, using 37,123,000 continuous monitoring data for enterprises in 31 cities. Three indicators were proposed to compare the spatial emission characteristics: industrial pollutant emission intensity (IPEI), industrial pollution concentration emission intensity (IPCEI) and the density of waste gas monitoring enterprise (DWGME). The IPEI and IPCEI of Yangquan, Taiyuan, Changzhi, Xingtai, Handan, and Hebi were considerably higher than the average level of the air pollution transmission channel cities (APTCC). The industrial SO2 concentration emission intensity in Yangquan, Hebi, Laiwu were 1826.9, 462.8, 301.4 mg m−3 per trillion yuan, more than twice the regional average for the 31 cities. We found there was a significant positive correlation between different industrial pollutants in the BTH and surrounding areas. Industrial SO2 emission have a positive correlation with industrial NOx emission in most of BTH cities, the correlation in Xingtai, Hengshui, Taiyuan were respectively 0.855, 0.969,0.696. Data mining and statistics on different time scales could be used to analyze the characteristics of industrial atmospheric emission sources, and could be applied in environmental decision support systems to make air pollution management more objective, reliable, and powerful.

In this work, we present field measurement data and modeling of air pollutant during one season at an urban area in Sousse, east Tunisia. We analyzed the average pollutant emission and we used our data to evaluate a dispersion model. The impact of various meteorological factors on pollutants concentrations has been studied. The model predicts that the concentrations of CO and CO2 in an urban area can reach 50 mg·m−3 and 185 mg·m−3 respectively. The height of the chimney, the wind velocity, the fuel nature, the air excess and the combustion temperature have an influence on the concentrations of pollutants and their dispersion.

As one of the energy-intensive and high-polluted industries, steel industry is facing great challenges of energy-saving and emission reduction. In this study, a bottom-up approach is used to build the inventory of air pollutants in China's steel industry. We analyzed the temporal and spatial characteristics of the atmospheric emission inventory of China's steel industry. The results show that: (1) In 2015, the total amount of SO2, NOx, PM, PM2.5, PM10 and PCDD/Fs emissions from Chinese steel industry were 1697.58kt, 1017.24kt, 4028.01kt, 849.02kt, 1330.53kt and 1216.83g I-TEQ, respectively. SO2, NOx, PM, PM10 and PCDD/Fs emissions mainly came from the sintering process, and PM2.5 came from the converter process. (2) NOx emissions show an “upward” trend, while SO2 emissions depict a “slowdown” trend. PM, PM2.5, PM10 and PCDD/Fs emissions present inverse U-shape trends. (3) The air pollutant inventory of Chinese steel industry indicates obviously spatial characteristics. Taking SO2 emissions in 2015 as an example, SO2 emissions from steel industry in North China and East China reached 1006.63kt, accounting for 65.2% of the total emissions. Hebei, Jiangsu and Shandong provinces where locate intensive traditional steel enterprises with majority of steel products generated SO2 emissions of approximately 404.04kt, 171.83kt and 156.28kt respectively, accounting for 23.80%, 10.12% and 9.20% total emissions of China's steel industry. (4) The simulation model of air pollutants (SO2, PM) was established taking adjusted production capacity and layout of steel industry into consideration, the simulation suggests that SO2 and PM emissions are projected to decrease by 1Mt, 2 Mt, respectively.

Carbon dioxide (CO2) and methane (CH4) are important greenhouse gases in the atmosphere and have large impacts on Earth's radiative forcing and climate. Their natural and anthropogenic emissions have often been in focus, while the role of human metabolic emissions has received less attention. In this study, exhaled, dermal and whole-body CO2 and CH4 emission rates from a total of 20 volunteers were quantified under various controlled environmental conditions in a climate chamber. The whole-body CO2 emissions increased with temperature. Individual differences were the most important factor for the whole-body CH4 emissions. Dermal emissions of CO2 and CH4 only contributed ~3.5% and ~5.5% to the whole-body emissions, respectively. Breath measurements conducted on 24 volunteers in a companion study identified one third of the volunteers as CH4 producers (exhaled CH4 exceeded 1 ppm above ambient level). The exhaled CH4 emission rate of these CH4 producers (4.03 ± 0.71 mg/h/person, mean ± one standard deviation) was ten times higher than that of the rest of the volunteers (non-CH4 producers; 0.41 ± 0.45 mg/h/person). With increasing global population and the expected large reduction in global anthropogenic carbon emissions in the next decades, metabolic emissions of CH4 (although not CO2) from humans may play an increasing role in regional and global carbon budgets.

This study draws the link between COVID-19 and air pollution (ground ozone O3) from February 29, 2020 to July 10, 2020 in the top 10 affected States of the US. Utilizing quantile-on-quantile (QQ) estimation technique, we examine in what manner the quantiles of COVID-19 affect the quantiles of air pollution and vice versa. The primary findings confirm overall dependence between COVID-19 and air pollution. Empirical results exhibit a strong negative effect of COVID-19 on air pollution in New York, Texas, Illinois, Massachusetts, and Pennsylvania; especially at medium to higher quantiles, while New Jersey, Illinois, Arizona, and Georgia show strong negative effect mainly at lower quantiles. Contrarily, COVID-19 positively affects air pollution in Pennsylvania at extreme lower quantiles. On the other side, air pollution predominantly caused to increase in the intensity of COVID-19 cases across all states except lower quantiles of Massachusetts, and extreme higher quantiles of Arizona and New Jersey, where this effect becomes less pronounced or negative. Concludingly, a rare positive fallout of COVID-19 is reducing environmental pressure, while higher environmental pollution causes to increase the vulnerability of COVID-19 cases. These findings imply that air pollution is at the heart of chronic diseases, therefore the state government should consider these asymmetric channels and introduce appropriate policy measures to reset and control atmospheric emissions., Graphical abstract Image 1, Highlights • Overall dependence observed between COVID-19 and air pollution. • US states adopted “Lockdown” measures to limit COVID-19 spread. • Lockdown measures temporarily decrease air pollution. • Highly polluted areas show higher intensity of COVID-19. • Tackling air pollution can be an alternative policy of easing lockdown.

One of the most important problems in the cities is atmospheric emission of anthropogenic origin. This problem is the key challenge mostly for city municipalities but also for business stakeholders, which are involved in freight transport at urban areas. One of the most important and efficient solutions to reduce this negative impact is implementation of electric vehicles. In recent years many activities and developments in this area have been done. This paper is focused on utilization of multi-criteria analysis for electric vehicles selection in the context of their usability for deliveries realization in cities. Moreover, it also presents general issues regarding the use of alternative fuels in motor vehicles, with emphasis on electric vehicles. It discusses the extent to which electric vehicles are used. It describes the key parameters for determining the usability of electric vehicles in urban deliveries. Based on the formulated assumptions, a multi-criteria model is proposed to enable selecting, out of the defined vehicles catalogue, solutions that are optimal in terms of potential effectiveness. The general aim of the paper is to support the logistics companies’ decision makers in the improvement of the freight vehicles fleets, taking into account the sustainable city logistics expectations.

Sulfur trioxide (SO3) pollution is becoming another severe problem in coal-fired power plants after SO2, NOx, and PM, however, the characteristics of SO3 emission in China remains unclear. In this paper, we established a refined activity data, and summarized the removal efficiency of different control technologies according to the literature review and field test results. An emission inventory of SO3 from coal-fired power plants in China between 2009 and 2014 was developed, which indicated the SO3 emission increased from 199.7 kilotons (kt) to 314.6 kt at an average annual growth rate of 9.7%. The results show that Neimenggu, Shānxi, Jiangsu, Shandong, Guangdong and Guizhou were the largest emitters, accounting for 49.7% of the total SO3 emissions in 2014. We analyzed the historical data with ArcGIS system, which allocates the emission into 36 km × 36 km grid cells. In addition, the result shows the unevenly spatial distribution. Combined with future economic development as well as implementation of policy, three different scenarios were set to project SO3 emission in coal-fired power plants in 2020, which represented the potential of SO3 emission reduction. Compared with scenario A, SO3 emission can be reduced to 83.9 kt in scenario B, and in scenarios C, SO3 emission can be reduced to 38.4 kt. Coal-fired power plants should adopt different technology routes to meet the ultra-low emission requirement and reduce the SO3 emission according to the boiler type, sulfur content, and the emission standard.

This article empirically compares the effectiveness of relative versus absolute performance standards in motivating compliance actions. By leveraging a unique set of Chilean administrative panel data, I examine a natural experiment created by a change in the performance standard used to incentivize the reduction of particulate matter in the atmospheric emissions of stationary pollution sources in the Santiago Metropolitan Region. I find that the absolute standard drove ∼21% less emissions cleanup than did the relative standard. I also demonstrate how sharp heterogeneity in responses to the change in standards is predictable based on an ex-ante identifiable type-categorization, which leads to the broadly-applicable conclusion that stricter regimes drive more compliance actions when imposed via an absolute performance standard compared to a relative standard. The extension of this framework provides a general means of anticipating whether an absolute or relative performance standard will drive higher rates of compliance actions in other settings.

Green roofs, as part of urban green structures, have been pointed out as the solution to pursuit the goal of healthy cities. This study aims to investigate the direct, focused on meteorological changes, and indirect, related to both meteorological and emissions changes, impacts of green roofs on air quality (PM10, NO2 and O3). For that, the numerical modelling system composed by the WRF-SLUCM-CHIMERE models was applied to a 1-year period (2017), having as case study the Porto urban area. The EnergyPlus model was also applied to estimate the green roofs impacts on the building's energy needs and related impacts on air quality and atmospheric emissions. The analysis of the direct impacts showed that green roofs promote a temperature increase during the autumn and winter seasons and a temperature decrease during the spring and summer seasons. Both negative - concentrations increase - and positive - concentrations decrease - impacts were obtained for the primary, PM10 and NO2, and secondary, O3, air pollutants, respectively, due to changes in the dynamical structure of the urban boundary layer. The indirect effects of green roofs showed their potential to enhance the buildings energy efficiency, reducing the cooling and heating needs. These changes in energy consumption promoted an overall decrease of the environmental and economic indicators. Regarding air quality, the impact was negligible. The obtained results highlight the need for a multipurpose evaluation of the impacts of green roofs, with the different effects having to be traded off against each other to better support the decision-making process.

Iron ore sintering is the main process of fines agglomeration for ironmaking with relevant particulate matter and trace element emissions of integrated steel plants. Due to the high environmental and human health impacts caused by trace elements, legislations are becoming more stringent for regulating emissions of the trace elements. This review consolidates several studies in the sector, focusing on the sources, behavior, and technologies employed to control emissions of trace elements during iron ore sintering. The emission of trace elements is strongly dependent on the characteristics of raw materials, operating parameters and technologies used for their abatement. Iron ore is the main responsible material for emissions of trace elements during sintering as it undergoes a series of physicochemical transformations throughout the process. In general, trace elements may remain in the solid-state, volatilize during combustion and recondense in the cleaning system, or remaining in the gaseous state during the flue gas treatment. Although most trace elements are retained in air pollution control devices in the form of particulates, volatile and semi-volatile elements (As, Se, Hg, Cd, etc) can remain as gases or concentrate in the finer particulates. Modern technologies have demonstrated high efficiency in removing these elements from the flue gases.

The combination of anthropogenic activities and long-term atmospheric transport has resulted in a sustained increase in global mercury concentrations in air, in water and on land. The Minamata Convention on Mercury (MCM), is a global treaty with the goal of protecting human health and the environment from anthropogenic releases of mercury. This study aimed to quantify the mercury inputs and outputs in China in 2016–2019 according to five source categories and investigate the effect of an accelerated scenario/technology transformation required by the MCM on the subsequent distribution of mercury among environmental and intermediate reservoirs. Mercury releases to natural environment decreased dramatically after the MCM, such that around 840 t of mercury was released to those reservoirs in 2019, which is less than 21% of that in 2016 (1,063 t) when an accelerated scenario/technology transformation (STranf) was taken into consideration. Applying the accelerated STranf can hardly change the total release amount to the natural environment, also can reduce 53 t and 58 t of atmospheric emission in 2018 and 2019 respectively. Atmospheric emission was most sensitive to STranf, followed by emissions to land and water. This is the first attempt to provide a systematic evaluation of the effectiveness of the MCM based on the hypothetical expectations. As the MCM moves into the implementation phase, further information from scientific data and studies is critically needed to support decision-making and management. The results of this study can provide such information, facilitating the creation of strategic management policies for mercury as the MCM is implemented in China.

Based on oil fate modeling of the Deepwater Horizon spill through August 2010, during June and July 2010, ~89% of the oil surfaced, ~5% entered (by dissolving or as microdroplets) the deep plume (900 m), and ~6% dissolved and biodegraded between 900 m and 40 m. Subsea dispersant application reduced surfacing oil by ~7% and evaporation of volatiles by ~26%. By July 2011, of the total oil, ~41% evaporated, ~15% was ashore and in nearshore (10 m) sediments, ~3% was removed by responders, ~38.4% was in the water column (partially degraded; 29% shallower and 9.4% deeper than 40 m), and ~2.6% sedimented in waters10 m (including 1.5% after August 2010). Volatile and soluble fractions that did not evaporate biodegraded by the end of August 2010, leaving residual oil to disperse and potentially settle. Model estimates were validated by comparison to field observations of floating oil and atmospheric emissions.

Background Manizales is a city in Colombia that presents high rates of thyroid cancer. It has a medium industrial development and there are concerns of the impact of their emissions on health, particularly on thyroid cancer. In this paper we characterize the geographical pattern of industrial atmospheric emissions of suspected thyroid carcinogens. Methods We systematized data of industries in two groups. First, those with reports of atmospheric emissions of suspected thyroid carcinogens (reporting facilities – RFs), and then, industries not required to report or facilities with no-available emissions data but belonging to the same SIC-codes than RFs (nonreporting facilities – non-RFs). For non-RFs, annual average atmospheric emissions were estimated using a per-employee algorithm. The spatial pattern of sources emitting carcinogens was represented by plotting facilities by size and amounts of specific pollutants released. Results We found 11 RFs and 25 non-RFs in urban Manizales. RFs belong to the metalworking industries, plastics & rubber, manufacture of electrical and electronic devices, waste incineration, cremation, and meat production. Most of them were concentrated in the southeast of the city. Several RFs reported atmospheric emissions of carcinogens exceeding maximum permitted emission limits set in Colombian law. Most of non-RFs were micro and small industries, and were clustered in the southeast of the city and along the main road axis. Conclusions We found clusters of pollution sources near densely populated areas. Thyroid cancer incidence might be greater in areas closer to industries than in furthest areas. We will submit a paper that studies this hypothesis soon.

High-energy materials such as emulsions, slurries and ammonium-nitrate fuel-oil (ANFO) explosives play crucial roles in mining, quarrying, tunnelling and many other infrastructure activities, because of their excellent transport and blasting properties. These explosives engender environmental concerns, due to atmospheric pollution caused by emission of dust and nitrogen oxides (NOx) from blasts, the latter characterised by the average emission factor of 5 kg (t AN explosive)−1. This first-of-its-kind review provides a concise literature account of the formation of NOx during blasting of AN-based explosives, employed in surface operations. We estimate the total NOx emission rate from AN-based explosives as 0.05 Tg (i.e., 5 × 104 t) N per annum, compared to the total global annual anthropogenic NOx emissions of 41.3 × 106 t N y−1. Although minor in the global sense, the large localised plumes from blasting exhibit high NOx concentration (500 ppm) exceeding up to 3000 times the international standards. This emission has profound consequences at mining sites and for adjacent atmospheric environment, necessitating expensive management of exclusion zones. The review describes different types of AN energetic materials for civilian applications, and summarises the essential properties and terminologies pertaining to their use. Furthermore, we recapitulate the mechanisms that lead to the formation of the reactive nitrogen species in blasting of AN-based explosives, review their implications to atmospheric air pollution, and compare the mechanisms with those experienced in other thermal and combustion operations. We also examine the mitigation approaches, including guidelines and operational-control measures. The review discusses the abatement technologies such as the formulation of new explosive mixtures, comprising secondary fuels, spin traps and other additives, in light of their effectiveness and efficiency. We conclude the review with a summary of unresolved problems, identifying possible future developments and their impacts on the environment with emphasis on local and workplace loads.

Brominated flame retardants (BFRs) are chemicals that are now omnipresent in the environment and have been detected in different matrices from different parts of the world. They are semivolatile organic compounds (SVOCs), hence they partition between air, water, soil and sediment. Atmospheric long range transport (LRT) is commonly considered the swiftest route for SVOCs to reach remote environments. As a results, the Stockholm Convention on Persistent Organic Pollutants (POPs) advocates air monitoring as a key measure to assess the effectiveness of global control initiatives. There is little information of atmospheric BFR levels in the African continent, which makes it impossible to understand the regional as well as global perspective of these pollutants in the atmosphere. The aim of this review is therefore to establish scientific reasons to explain why it is necessary to have atmospheric research in Africa, and provide research gaps that need to be considered in further studies in order to better understand these pollutants in the atmosphere. To date there are about 57 published studies on BFRs in different matrices in various countries of the African continent, out of which, only three have concentrated on the atmosphere. The amounts are not as high as detected in other regions but are likely to increase due to the fact that the continent is developing at a fast rate thus an anticipated increase in BFRs use. The review therefore provides different recommendations which all clearly develop a foundation of the necessity of air monitoring of BFRs in the African continent.

Coal-fired industrial boilers (CFIBs) are a significant source of trace metals (TMs) emissions, due to its large number and widespread industry application. In this study, a highly resolved of county-based atmospheric emission inventory of Hg, As, Cd, Cr and Pb for Chinese CFIBs in 2017 is established firstly based on integrated source-specific information of both activity level and air pollution control devices (APCDs) from ~61,000 CFIBs in mainland China. Our results estimated that the total emissions of Hg, As, Cd, Cr and Pb from national CFIBs in 2017 were about 25.46, 115.33, 7.04, 371.40, and 589.76 t, respectively. Hg0 was the majority species of atmospheric Hg, accounting for 71.5% of the total Hg emission. The peak emission intensities of five TMs were mainly concentrated in northern and eastern region of China due to its large demand of coal consumption for winter heating, broad economic activity, as well as high population density. Monthly emission characteristics of TMs exhibited seasonal peak. The overall uncertainties of the newly updated emission inventory were estimated at the ranges of −42.0%–45.5%. Generally, TMs emissions from Chinese CFIBs were effectively controlled through implementing energy substitution, APCDs upgrading, and ultra-low emission (ULE) retrofitting in different regions of China, which contributed to 18.8%–29.4% of five TMs emission reductions. We believe that our highly resolved county-level emission inventory will be comprehensively explored the current tempo-spatial emission characteristics of atmospheric TMs from Chinese CFIBs and the forecast results will be useful for developing effective emission control programs for policy makers in the county levels and improving the regional air quality in the future.

Dynamically tracking flows and stocks of problematic chemicals in products (CiPs) in the global anthroposphere is essential to understanding their environmental fates and risks. The complex behavior of CiPs during production, use and waste disposal makes this a challenging task. Here we introduce and describe a dynamic substance flow model, named Chemicals in Products - Comprehensive Anthropospheric Fate Estimation (CiP-CAFE), which facilitates the quantification of time-variant flows and stocks of CiPs within and between seven interconnected world regions and the generation of global scale emission estimates. We applied CiP-CAFE to polychlorinated biphenyls (PCBs), first to evaluate its ability to reproduce previously reported global-scale atmospheric emission inventories and second to illustrate its potential applications and merits. CiP-CAFE quantifies the pathways of PCBs during production, use and waste disposal stages, thereby deducing the temporal evolution of in-use and waste stocks and identifying their long-term final sinks. Time-variant estimates of PCB emissions into air, water and soil can be attributed to different processes and be fed directly into a global fate and transport model. By capturing the international movement of PCBs as technical chemicals, and in products and waste, CiP-CAFE reveals that the extent of global dispersal caused by humans is larger than that occurring in the natural environment. Sensitivity analysis indicates that the model output is most sensitive to the PCB production volume and the lifetime of PCB-containing products, suggesting that a shortening of that lifetime is key to reducing future PCB emissions. Keywords: Chemical in product, PCBs, Substance flow analysis, Anthroposphere, Emission, Flow

Dechlorane Plus (DP) is a chlorinated flame retardant applied in parallel to or as a replacement product for regulated flame retardants. Detection of DP in environmental media all over the world in recent years necessitates the development of detailed global emission estimates for environmental model studies. Based on production, usage and disposal data two global atmospheric emission scenarios were made with a detailed geographical distribution. The total DP emission is estimated to be 0.02 t/year and 3.2 t/year in a low and high emission scenario, respectively, reflecting the uncertainties in production volumes and emission factors. The emission estimates are tested by implementation in the Danish Eulerian Hemispheric Model, an advanced chemistry-transport model. An evaluation against measurements in the Arctic from the early 2010s, considered to represent background concentrations, shows that the predicted concentration range for the high emission scenario is in line with the measured range, whereas the predicted concentrations for the low emission estimate are more than a factor of 100 lower than the measurements, rendering the high emission estimate most probable.

Little is known about how forests adjust their gas-exchange mode while atmospheric CO2 rises globally and air quality changes regionally. The present study aims at addressing this research gap for boreal spruce trees growing in three different regions of Canada, submitted to distinct levels of atmospheric emissions, by examining the amount of carbon gained per unit of water lost in trees, i.e., the intrinsic water use efficiency (iWUE). Under pristine air quality conditions, middle-to long-term trends passed from no-reaction mode to passive strategies due to atmospheric CO2, and short-term iWUE variations mostly ensue from year-to-year climatic conditions. In contrast, in trees exposed to pollutants from a copper smelter and an oil-sands mining region, air quality deterioration generated swift, long-term iWUE rises immediately at the onset of operations. In this case, the very active foliar strategy sharply reduced the intra-foliar CO2 (Ci) pressure. Statistical modeling allowed identifying emissions as the main trigger for the iWUE swift shifts; subsequent combined effects of emissions and rising CO2 led to passive foliar modes in the recent decades, and short-term variations due to climatic conditions appeared all along the series. Overall, boreal trees under different regional conditions modified their foliar strategies mostly without changing their stem growth. These findings underline the potential of acidifying emissions for prompting major iWUE increases due to lowering the stomatal apertures in leaves, and the combined influence of rising CO2 in modulating other foliar responses. A fallout of this research is that degrading air quality may create true divergences in the relationship between tree-ring isotopes and climatic conditions, an impact to consider prior to using isotopic series for paleo-climatic modeling.

Lead is a persistent pollutant and the subject of many environmental studies, yet, in Australia, the extent of atmospheric lead emissions from the use of leaded petrol is unquantified. This paper details the first comprehensive account of leaded petrol sales and its lead concentrations over the 70 years of use in Australia. The resulting atmospheric lead emissions are calculated to provide the most complete understanding of the volume of lead released to the Australian continent from the consumption of leaded petrol. Atmospheric emissions of lead to the entire Australian continent from leaded petrol are calculated to total 240,510 tonnes over seven decades of use, peaking at 7869 tonnes in 1974. Total emissions for individual states and territories range from 1745 to 67,893 tonnes, with New South Wales responsible for the largest emissions. The effect of regulations on allowable concentrations of tetraethyl-lead additives are observed in the reduction of lead emissions in New South Wales and Victoria. The consequences to human health and the environment of leaded petrol consumption in Australia's populous cities are examined against historical air quality data and blood lead levels.

© 2015 Elsevier B.V. A significant problem exists concerning contamination of the environment, especially air pollution, and the consequent climatic change. Considering that agricultural vehicles that use fossil fuels emit significant amounts of atmospheric pollutants, the main objective of this paper is to include techniques to reduce the fuel consumption in the controls system of robotic tractors used in agriculture tasks and thereby reduce the atmospheric emissions from these automated applications. To achieve this goal, the first step is to analyze fuel consumption in real time for each of the applications to be improved and to implement the consumption model of a robotic tractor for each task, considering the mechanical energy variations, the performance losses, the energy used to overcome friction and the energy required by the given task. For calculating the mechanical energy, the model considers the potential energy of the system, which is a function of the mass, elevation and gravity. The terrain elevations are estimated from GeoTIFF images of DEM data, which have a pixel size equal to 1. arc second (approximately 30. m at the Equator), and an accuracy of integer meters. Regarding the system mass, the possible loss of mass from applying the treatment is considered. For estimating the frictional forces, the rolling resistance coefficient of the terrain surface conditions is used.The consumption model has been validated experimentally using real agricultural vehicles and implements within the RHEA project (FP7-NMP 245986), in which the instantaneous fuel consumption was measured.This fuel reduction method is applied to three different treatments: weed control on herbaceous crops through the spraying of herbicides, weed control on fire-resistant crops with wide furrows through plowing and flame treatment, and pest control on trees through fumigation using insecticides.Finally, a fuel reduction procedure is applied to each task using the system model implemented to predict the energy requirements. This enables one to find the optimum path plan with respect to fuel consumption. These theoretical results are compared with the experimental results. In addition, the goal is to demonstrate the fuel reduction technique by performing field experiments to show that the use of this method of fuel reduction leads to an reduced fuel consumption and thus reduces atmospheric emissions from agricultural tasks. The results obtained revealed that this fuel reduction method significantly reduces the energy requirements, with the consequent reduction in fuel consumption and atmospheric pollutant emissions., The research leading to these results received funding from the European Union’s Seventh Framework Programme [FP7/2007-2013] under Grant Agreement n. 245986.

Hazardous trace elements (HTEs) cannot be eliminated through microbial degradation in the environment, and moreover, high concentrations of HTEs do not only impose a long term and non-reversible burden on biogeochemical cycling in the ecosystem, but also threaten the health and life of animals and human beings. Taking account of the obvious differences on economic development and technology diffusion among countries, we construct the best available representation of time-varying emission factors of HTEs for primary anthropogenic activities in five regions of the world. Anthropogenic atmospheric emission inventory of twelve typical HTEs (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn) characterized by global region, long-term spans and high spatiotemporal resolutions are elaborately established by synthetically using emission factor methods and ArcGIS tools. Our results show that the global total emissions of twelve HTEs from primary anthropogenic sources have decreased from about 268262 tons in 1995–216893 tons in 2012, with an annual decline rate of 1%. For HTE emissions in 2012, coal combustion sources (CC, accounting for about 35–97% of Hg, Se, Cr, Mn, Co and Zn emissions), liquid fuel combustion (LFC, accounting for about 31% of Pb emission), nonferrous metal smelting (NFMS, being responsible for about 51–77% of As, Cd and Ni emissions) and brake wear (BW, contributing about 42–67% of Sb and Cu emissions) are identified as primary contribution sources for the corresponding HTEs. Asia is the highest HTEs emitting continent in 2012, accounting for approximately 59% of the global total emissions. Generally, China, Chile, India, Russia, the United States and South Africa represent the top countries with high HTE emissions from anthropogenic sources. Therein, China ranks as the world's largest country with HTE (except for Sb) emissions. In contrast, the U.S. is found as the country producing the largest Sb emission throughout the world. The top emission intensities of HTEs are found in Eastern and Southern Asia and Eastern Europe.

Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants but they are of concern and are currently being phased-out because of their environmentally hazardous properties and their potential to cause adverse health effects. We analyzed PBDEs in Zurich, Switzerland, and applied a multi-media environmental fate model to back-calculate the rate of PBDE emission to air. PBDE concentrations in ambient air were measured in summer 2010 and winter 2011 in the city center of Zurich. Concentrations were higher in summer (sum PBDEs 118-591 pg m(-3)) than in winter (sum PBDEs 17-151 pg m(-3)), and are on the upper end of concentrations reported in literature for urban sites with no point sources of PBDEs. The emissions derived from our measurements (summer: 53-165 μg capita(-1) d(-1), winter: 25-112 μg capita(-1) d(-1)) and extrapolated to annual emissions for Switzerland (114-406 kg a(-1)) lie in the middle of ranges reported on the basis of substance flow analyses and emission inventories. The difference between summer and winter emissions is small compared to the difference that would be expected from the temperature dependence of PBDE vapor pressure, which would be consistent with emissions occurring to a large extent from flame-proofed materials located indoors under nearly constant temperature conditions and/or emissions to air occurring by suspension of particles containing PBDEs. Compared to previous studies in Switzerland, concentrations and emissions of PBDEs appear to have increased during the last five years with an increasing contribution of decabromodiphenyl ether, despite the addition of PBDEs to national and international regulations.

This study screens and rank Cambodian sedimentary basins in terms of their containment, capacity, and feasibility for the geological storage of CO 2 . The results of the screening and ranking procedure indicate that the Khmer Basin is the most suitable basin, followed by the Kampong Saom and Tonle Sap basins. A quantitative volumetric assessment-based evaluation of CO 2 storage capacity is performed on these three suitable basins. The evaluation yields a range in the national CO 2 storage capacity of 90 Mt (in structural traps) to 45 Gt (in hydrodynamic traps), representing low- and high-case estimates, respectively. The saline aquifers associated with this storage capacity should be considered prospective storage options as hydrodynamic traps because of containment and capacity issues associated with the structural traps. Eight major point sources of CO 2 are identified that have a combined output (estimated for 2008–2024) of 43.1 Mt annually and 82 billion m 3 in place, and the potentially prospective matched storage capacity is assumed. Overall, a combination of the initial suitabilities of the basins and estimates of prospective matched storage capacity shows that the Khmer, Kampong Saom, and Tonle Sap basins may provide a solution to the problem of reducing future atmospheric emissions. The present results should assist both exploration geologists and experts in carbon capture and storage to gain a better understanding of the CO 2 storage resources of Cambodia. However, the results should be regarded as preliminary because of the limited available data on which the assessments were based; future geological and geophysical data should improve the reliability of the estimates of carbon storage capacity reported here.

In this study, we estimated atmospheric Cd emissions from anthropogenic sources in China from 1990 to 2010 on the basis of consumption or output data and emission factors. China emitted approximately 2186 t Cd to the atmosphere in 2010, with approximately 77% and 14% of the emissions arising from non-ferrous metal smelting and coal combustion, respectively. Temporal changes in the total Cd emissions were characterized by two periods of increase (1990–2000 and 2001–2010) and a short period of decrease (2000–2001) due to application of energy-saving and cleaner production technologies. Overall, atmospheric Cd emissions increased from 474 t in 1990 to 2186 t in 2010 due to rapid economic growth, whereas energy-saving and cleaner production technologies have been in use since 2000. Spatial distribution of the atmospheric Cd emissions was dominated primarily by non-ferrous metal smelting and coal combustion. Emissions are high in Hunan and Yunnan Provinces because of high production non-ferrous metal smelting and in Shandong Province because of high coal consumption and moderate non-ferrous metal production.

In 2011, the European Pollutant Release and Transfer Register (E-PRTR) inventory of diffuse emissions became available, providing data on a range of atmospheric emissions at a 5 km resolution across Europe. The data are produced from spatially disaggregated emissions totals for countries, and must be validated before being used at a sub-national level. The UK government maintains a 1 km resolution emissions inventory based on a bottom-up methodology by which a validation is possible. The UK National Atmospheric Emissions Inventory data are used to assess at what geographic scale the new E-PRTR data might be most useful. This paper compares the two data sets and estimates city-level transportation CO2 emissions for 149 EU cities. We find that at a functional boundary level the two datasets match well.

This paper quantifies the efficiency of emission control measures in agriculture at landscape scale on the N deposition and critical N load exceedances in Natura 2000 sites. The model INITIATOR2 was run with spatially explicit farm data to predict atmospheric emissions of ammonia. These emissions were input of an atmospheric transport model to assess the N deposition in the Natura 2000 sites. Using the Dutch province of Overijssel as a case study, calculations for the year 2006 show that only 35% of the N deposition in the Natura 2000 sites were caused by agricultural NH3 emissions within the province. Comparatively most cost-efficient measures were low-emission application, followed by measures to reduce the protein content in feed. Relocating farms out of the Natura 2000 sites was very cost inefficient. Since critical N depositions of the Natura 2000 sites in Overijssel are largely exceeded in more than 90% of the area, the evaluated abatement measures were, however, not effective to reduce the area exceeding critical loads when only applied within the province Overijssel. Reductions of N deposition to a level below critical loads can only be achieved with the support of national and international emission reductions.

Geologic storage of CO2 for atmospheric emissions reductions imposes unique requirements to document containment. Monitoring pressure in strata above the injection interval is a fit-to-purpose technique to document performance of the confining system and the degree of isolation provided by existing wellbore completions. The Cranfield (Mississippi, USA) enhanced oil recovery and sequestration project provides downhole high-precision pressure and temperature measurements at an observation well at two depths: at the injection interval and at a selected above zone monitoring interval (AZMI). To attempt to reconcile disparate observations from the pressure and temperature measurements, we present a simple set of coupled analytical models that enable diagnosis of above-zone monitoring data. Concurrent pressure and temperature measurements are especially valuable because they independently constrain the effective permeability of a leakage path along wellbore. Application of the models to the Cranfield data shows that the observed pressure elevation requires a model with an extremely large leakage rate and an effective wellbore permeability in order of tens of darcies. The temperature model shows that this rate would be large enough to raise the temperature in the monitoring zone significantly, which is not observed. We conclude that the observation well is unlikely to be leaking.

This paper examines the emissions from ships at berth in the Port of Bergen in Norway. As well as estimating the quantity of emissions, we look at estimates of the external costs of pollution and derive a cost for the pollutants emitted by the ships at berth in Bergen. The cost of these emissions is estimated at between €10 m and €21.5 m per year.

In this study the Impact Pathway Approach (IPA) was used to calculate the external costs associated with indirect exposure, via topsoil ingestion, to atmospheric emissions of lead (Pb) from a waste-to-energy plant in Denmark. Three metal-specific models were combined to quantify the atmospheric dispersion of lead, its deposition and accumulation in topsoil, and the increase in blood lead concentration for children resulting from lead intake via topsoil ingestion. The neurotoxic impact of lead on children was estimated using a lead-specific concentration-response function that measures impaired cognitive development in terms of IQ points lost per each incremental μg/dl of lead in blood. Since IQ loss during childhood can be associated with a percent decrease in expected lifetime earnings, the monetary value of such an impact can be quantified and the external costs per kg of lead emitted from the plant were then calculated. The costs of indirect exposure calculated over a time horizon of 100 years, for the sub-population of children of 0–3 years, and discounted at 3%, were in the range of 15–30 €/kg. Despite the continued accumulation of lead in topsoil resulting in increasing future indirect exposure, the results indicate that costs associated with this exposure pathway are of the same order of magnitude as costs associated with direct exposure via inhalation, calculated at 45–91 €/kg. Moreover, when the monetary value of future impacts is discounted to the present, the differences between the two exposure pathways are diminished. Finally, setting a short time horizon reduces the uncertainties but excludes part of the costs of indirect exposure from the assessment.

The Flin Flon copper–zinc smelter is a site of concern as it has been the largest single source of atmospheric mercury emissions in Canada. Variations in total mercury concentration and mercury isotopic composition were determined in three lake sediment cores at different distances from the Flin Flon smelter. Total mercury concentrations ranged from 90 to 19,000 ng/g and were much higher in cores obtained closer to the smelter. The observed mass dependent mercury isotope fraction (MDF) varied significantly among sediment cores collected closer to the smelter (− 0.67 to − 1.48‰) and cores collected from further away (− 1.44 to − 2.71‰). Mass independent fraction (MIF) was detectable in some but not all samples (− 0.05 to 0.14‰). A simple binary mixing model showed that mercury in all sediment samples investigated in this study originated in variable proportions from the Flin Flon smelter. The study demonstrated that mercury isotope ratio measurements could serve as an effective tool for tracing mercury contamination caused by atmospheric emissions from metal smelting activities.

Chemical fumigants are routinely used for soil disinfestation of high value crops. Good agricultural practices (GAPs) are needed to reduce their human health risks, environmental impacts, and improve their cost-effectiveness. This study investigated the effect of fumigant application methods on soil persistence and emission of 1,3-dichloropropene (1,3-D) and chloropicrin (CP). Field experiments were conducted to measure the individual and combined effects of pre-application tillage practices, fumigant application technology, and plastic films on 1,3-D soil concentrations to obtain a numerical index ( CT value) to estimate their potential for pest control efficacy and to compare soil persistence, atmospheric flux rate, and cumulative emission of CP and 1,3-D under two diverse application scenarios. Greater 1,3-D soil vapor concentrations were observed by combining a pre-application soil seal with low soil disturbance application technology when compared to pre-application soil tillage and the use of back-swept application shanks. Under high density polyethylene plastic, the low disturbance scenario resulted in time weighted exposure concentration ( CT ) values ranging from 6.8 to 12.2 μg h cm −3 of soil as compared to CT values ranging from 2.9 to 5.4 μg h cm −3 under the conventional application scenario. Cumulative atmospheric emission of 1,3-D was decreased by 18% under the low disturbance scenario and atmospheric emission of CP by 21% when compared to a conventional application scenario. This study identified GAPs that can be readily implemented in the field to reduce the human and environmental impacts of soil fumigants and improve their cost-effectiveness under solid-tarp (broadcast) applications.

Estimates of atmospheric emissions of lead from anthropogenic sources in China from 1990 to 2009 are presented with the information on emissions of both total lead and its spatial distribution in regions. The total emissions during the period 1990–2009 are nearly 200 000 tons. Motor vehicle gasoline combustion was the largest source of anthropogenic emissions. The estimated release of 117 800 t of lead represented 60% of the total emissions. Substantial decline occurred in 2001, when the total emissions were about 81% less than the 2000 value. The reduced lead content of motor vehicle gasoline is the primary reason for the decreased in lead emissions in 2001. After leaded gasoline was phased out, coal combustion became the principal source of emissions. Based on data on emissions from 2005 through 2009, the emissions are concentrated in eastern and central China due to the high level of coal consumption and non-ferrous metal smelting. The five provinces with the largest amounts of lead emissions are Shandong, Hebei, Shanxi, Henan and Jiangsu. These five regions produced nearly 40% of the total.

We present a comparison of techniques for estimating atmospheric emissions from fires using Australia's 2009 “Black Saturday” wildfires as a case study. Most of the fires started on Saturday the 7th of February 2009 (a date now known as “Black Saturday”) and then spread rapidly, fanned by gale force winds, creating several firestorms and killing 173 people. The fires continued into early March, when rain and cooler conditions allowed the fires to be extinguished. In this study, we compare two new techniques (and one more established method) to estimate the total emissions of a number of atmospheric trace gases from these fires. One of the new techniques is a “bottom-up” technique that combines existing inventories of fuel loads, combustion efficiencies and emission factors with an estimate of burned area derived from MODIS rapid response daily fire counts. The other new method is a “top-down” approach using MODIS aerosol optical depth as a proxy for total amounts of trace gases emitted by the fires. There are significant differences between the estimates of emissions from these fires using the different methods, highlighting the uncertainties associated with fire emission estimates. These differences are discussed along with their likely causes and used as a vehicle to explore the merits of the different methods, and further constrain fire emissions in the future.

Iron ore sintering processes constitute significant sources of dioxins, and studies have confirmed a close correlation between polychlorinated naphthalenes (PCNs) and dioxin formation. Thus, iron ore sintering processes are thought to be a potential source of PCNs, although intensive investigations on PCN emissions from sintering processes have not been carried out. Therefore, the aim of the present study was to qualify and quantify PCN emissions from nine sintering plants operating on different industrial scales. PCN concentrations ranged from 3 to 983 ng m(-3) (0.4-23.3 pg TEQ(PCN) m(-3)) and emission factors ranged from 14 to 1749 mu g t(-1) (0.5-41.5 ng TEQ(PCN) t(-1)), with a geometric mean of 84 mu g t(-1) (2.1 ng TEQ(PCN) t(-1)). The estimated annual emission of PCNs from sintering processes in China was 1390 mg TEQ(PCN). These figures will assist in the development of a PCN emissions inventory. Regarding emission characteristics, PCNs mainly comprised low-chlorinated homologs. The ratios of several characteristic PCN congeners were also measured and compared with those from other sources. Taken together, these results may provide useful information for identifying the sources of PCNs produced by iron ore sintering processes. (C) 2012 Elsevier Ltd. All rights reserved.

Urban sprawl is altering the landscape, with current trends pointing to further changes in land use that will, in turn, lead to changes in population, energy consumption, atmospheric emissions and air quality. Urban planners have debated on the most sustainable urban structure, with arguments in favour and against urban compaction and dispersion. However, it is clear that other areas of expertise have to be involved. Urban air quality and human exposure to atmospheric pollutants as indicators of urban sustainability can contribute to the discussion, namely through the study of the relation between urban structure and air quality. This paper addresses the issue by analysing the impacts of alternative urban growth patterns on the air quality of Porto urban region in Portugal, through a 1-year simulation with the MM5-CAMx modelling system. This region has been experiencing one of the highest European rates of urban sprawl, and at the same time presents a poor air quality. As part of the modelling system setup, a sensitivity study was conducted regarding different land use datasets and spatial distribution of emissions. Two urban development scenarios were defined, SPRAWL and COMPACT, together with their new land use and emission datasets; then meteorological and air quality simulations were performed. Results reveal that SPRAWL land use changes resulted in an average temperature increase of 0.4 °C, with local increases reaching as high as 1.5 °C. SPRAWL results also show an aggravation of PM10 annual average values and an increase in the exceedances to the daily limit value. For ozone, differences between scenarios were smaller, with SPRAWL presenting larger concentration differences than COMPACT. Finally, despite the higher concentrations found in SPRAWL, population exposure to the pollutants is higher for COMPACT because more inhabitants are found in areas of highest concentration levels.

Multiple-year inventory of atmospheric emissions of cadmium (Cd), chromium (Cr), and lead (Pb) from coal burning in China have been established for the period 1980-2008 by using best available emission factors and annual activity data which are specified by different sub-categories of combustion facilities, coal types, and air pollution control devices. Our results show that the total emissions of Cd, Cr, and Pb have rapidly increased from 31.14 t, 1019.07 t, and 2671.73 t in 1980 to 261.52 t, 8593.35 t, and 12 561.77 t in 2008, respectively. The industrial sector ranks as the leading source, contributing similar to 88.3%, similar to 86.7%, and similar to 81.8% of the total Cd, Cr, and Pb emissions, respectively. Remarkably uneven spatial allocation features are observed. The emissions are primarily concentrated in the provinces of the northern and eastern region of China owing to the dramatic difference in coal use by the industrial and power sectors. Monthly temporal emission profiles for different sectors are established by using indexes such as monthly thermal electricity generation, monthly gross industrial output values and monthly average ambient temperature. For the power plants, there are two peaks during cold and hot season while for the industrial sector, emissions are most substantial in the summer and autumn season. Further, uncertainties in the bottom-up inventories are quantified by Monte Carlo simulation, and the overall uncertainties are demonstrated as -16% to 45% for Cd, -13% to 20% for Cr, and -21% to 48% for Pb, respectively. To better understand the emissions of these metals and to adopt effective measures to prevent poisoning, more specific data collection and analysis are necessary.

Multi-year (similar to 7 years) observations of aerosol optical and microphysical properties were conducted at a tropical urban location in Bangalore, India. As a consequence of rapid urbanization, Bangalore presents high local atmospheric emissions, which makes it an interesting site to study the effect of anthropogenic activities on aerosol properties. It has been found that both column (aerosol optical depth, AOD) and ground-level measurements (black carbon (BC) and composite aerosol mass) exhibit a weekly cycle with low aerosol concentrations on weekends. In comparison to the weekdays, the weekend reductions of aerosol optical depth, black carbon and composite aerosol mass concentrations were similar to 15%, 25% and 24%, respectively. The magnitude of weekend reduction of black carbon is as much as similar to 1 mu g m(-3). The similarity in the weekly cycle between the column and surface measurements suggests that the aerosol column loading at this location is governed by local anthropogenic emissions. The strongest weekly cycle in composite aerosol mass concentration was observed in the super micron mass range (>1 mu m). The weekly cycle of composite aerosol mass in the sub micron mass range (

A technique is described to independently validate the national emission inventories produced using the methodology of the Intergovernmental Panel on Climate Change (IPCC). A boundary layer budget approach is applied to the United Kingdom and an inverse modelling technique is used to derive total and spatial apportionment of emissions for CO, CO 2 , CH 4 , N 2 O, HFC-134a, HCFC-141b, HCFC-142b and HCFC-22. During the summer of 2005 and September 2006 an aircraft circumnavigating the UK was used to collect data upwind and downwind of the UK coast. The concentration measurements were inverted to produce mapped emissions of the UK. The modelled overall CO flux (2900 ± 107 kt yr −1 ) and spatial apportionment throughout the UK are remarkably consistent with the official UK NAEI (National Atmospheric Emission Inventory) inventory. The CO 2 total emissions (620 ± 105 Mt yr −1 ) and spatial apportionment are also close to the NAEI. However for N 2 O and CH 4 , the estimated annual fluxes, 500 ± 370 kt yr −1 and 3500 (range 0–8000 kt yr −1 ) respectively, are larger than the NAEI albeit with significant uncertainty. Emissions of four halocarbon compounds were also calculated with total emissions of 3.1 ± 0.4 kt yr −1 for HFC-134a, 0.9 ± 0.6 kt yr −1 for HCFC-141b, 0.56 ± 0.2 kt yr −1 for HCFC-142b and 3.8 ± 1.0 kt yr −1 for HCFC-22 consistent with other published data.

Parties to the LRTAP convention have agreed to annually report atmospheric emissions and are required to set up an emission inventory. As a minimum, parties shall use the latest version of the EMEP/EEA Air Pollutant Inventory Guidebook, but most countries - including the Netherlands - have set up their own inventory, which uses country specific information to supplement the information from the Guidebook. In this study, emissions estimated within the Dutch Emission Inventory are compared to emissions estimated using Guidebook emission factors and Dutch statistics for the year 2005. The objective is to explore the quality of both methods and to find major differences and similarities. The comparison shows that for most sources, emission estimates are within uncertainty ranges for both methodologies, especially for sources where a higher Tier (more detailed) methodology is used to estimate the emissions. This is in line with the Guidelines which indicate that for key categories a more detailed methodology should be used. The comparison also shows some surprising differences, such as large differences in emission factors (especially Tier 1) and missing sources (fireworks and abrasion of railway overhead wires, causing 16% of total copper emissions in the Netherlands) which have not been included in the Guidebook. This comparison is shown to be a useful tool to identify areas where improvements and further research are necessary. © 2010 Elsevier Ltd.

In Finland the deposition of strontium-89 ( 90 Sr) and strontium-90 ( 90 Sr) has been monitored since the early 1960s. The measured cumulative 90 Sr deposition in 1963–2005 is on average 1200 Bq m −2 , of which 150 Bq m −2 originates from the Chernobyl accident. Adding to this the deposition in 1945–1962 produces a value of 2040 Bq m −2 for the cumulative deposition in Finland. The nuclear explosion-derived deposition up to 1985 obtained in this study, 1850 Bq m −2 , is in good agreement with the zonal 90 Sr deposition of 1740 Bq m −2 in the 60°N–70°N latitude band estimated by UNSCEAR. The regional deposition patterns of 89 Sr and 90 Sr following the Chernobyl accident resemble those of the refractory nuclides such as 239,240 Pu and 95 Zr. The total deposition of Chernobyl-derived 90 Sr in Finland was about 5.3 × 10 13 Bq. This activity corresponds to 0.027% of the reactor core inventory and 0.66% of the atmospheric emissions from the accident. The corresponding figures for 89 Sr are 4.5 × 10 14 Bq, 0.023% and 0.56%, respectively.

India has become one of the biggest emitters of atmospheric pollutants from the road transportation sector globally. Here we present an up-to-date inventory of the exhaust emissions of ten species. This inventory has been calculated bottom-up from the vehicle mileage, differentiating by seven vehicle categories, four age/technology layers and three fuel types each, for the seven biggest cities as well as for the whole nation. The age composition of the rolling fleet has been carefully modelled, deducting about one quarter of vehicles still registered but actually out-of-service. The vehicle mileage is calibrated to the national fuel consumption which is essential to limit uncertainties. Sensitivity analyses reveal the primary impact of the emission factors and the secondary influence of vehicle mileage and stock composition on total emissions. Emission estimates since 1980 are reviewed and qualified. A more comprehensive inspection and maintenance is essential to limit pollutant emissions; this must properly include commercial vehicles. They are also the most important vehicle category to address when fuel consumption and CO 2 emissions shall be contained.

The global atmospheric emissions of the 16 polycyclic aromatic hydrocarbons (PAHs) listed as the US EPA priority pollutants were estimated using reported emission activity and emission factor data for the reference year 2004. A database for emission factors was compiled, and their geometric means and frequency distributions applied for emission calculation and uncertainty analysis, respectively. The results for 37 countries were compared with other PAH emission inventories. It was estimated that the total global atmospheric emission of these 16 PAHs in 2004 was 520 giga grams per year (Gg y −1 ) with biofuel (56.7%), wildfire (17.0%) and consumer product usage (6.9%) as the major sources, and China (114 Gg y −1 ), India (90 Gg y −1 ) and United States (32 Gg y −1 ) were the top three countries with the highest PAH emissions. The PAH sources in the individual countries varied remarkably. For example, biofuel burning was the dominant PAH source in India, wildfire emissions were the dominant PAH source in Brazil, while consumer products were the major PAH emission source in the United States. In China, in addition to biomass combustion, coke ovens were a significant source of PAHs. Globally, benzo(a)pyrene accounted for 0.05% to 2.08% of the total PAH emission, with developing countries accounting for the higher percentages. The PAH emission density varied dramatically from 0.0013 kg km −2 y in the Falkland Islands to 360 kg km −2 y in Singapore with a global mean value of 3.98 kg km −2 y. The atmospheric emission of PAHs was positively correlated to the country's gross domestic product and negatively correlated with average income. Finally, a linear bivariate regression model was developed to explain the global PAH emission data.

This paper reviews the information on trends of past emissions of mercury, lead, and cadmium in Europe, as well as examines current levels and future scenarios of these emissions. The impact of various factors on emission changes is discussed including the implementation of various strategies of emission controls in Europe. Future emissions are forecasted on the basis of various scenarios of economy growth in Europe, implementation of European and global legislation (e.g. the Kyoto agreement), population changes, etc. Changes of emissions of mercury, lead, and cadmium are then related to the changes of concentrations of these contaminants in air and precipitation samples at selected stations in Europe. It can be concluded that the reduction trends of anthropogenic emissions of cadmium and lead in Europe are similar to the reduction trends of air concentrations of these metals during the last 2 decades. Somewhat different relationship has been noted for changes in emissions and precipitation. In general for Europe, 60% reduction of Cd emissions was met by about 45% reductions of Cd concentrations in precipitation at the studied stations during the last 2 decades. There is a potential for further reduction of these emissions until the year 2010 up to about 37% for Cd, 51% for Pb, and 49% for Hg as estimated within various emission scenarios presented in the paper.

The paper by Reimann et al. (2008) is an echo of the debate carried out mainly by Clair Patterson and Robert Kehoe in the 1960s to 1980s about whether the enrichment of Pb in the biosphere and humans was a result of the global Pb contamination or due to natural causes and what impacts on human health were entailed ([Needleman, 1998] and [Nriagu, 1998]). Reimann et al. are also re-awakening the idea that the ‘plant pump’ is the reason for the surface enrichment of Pb in the soil (Goldschmidt, 1937). So is it time to revive this debate again? Are there reasons to expect that the enrichment of Pb and the change in Pb isotopic composition in surface soils is due to natural plant cycling and not due to the 1000-fold enrichment of Pb in the environment and humans since pristine times as originally suggested by Clair Patterson ([Patterson, 1965] and Settle and Patterson, 1980 D. Settle and C.C. Patterson, Lead in Albacore: guide to lead pollution in Americans, Science 207 (1980), pp. 1167–1176. View Record in Scopus | Cited By in Scopus (97)[Settle and Patterson, 1980])? Is it so that a changed plant uptake can explain the >90% reduction of Pb in mosses seen all over Europe since the 1970s, which co-occurs with reduced atmospheric emissions (e.g., [Berg and Steinnes, 1997a] and [Ruhling and Tyler, 2001])? Is there a reason to believe that plants, independent of the geological matrix below choose to take up Pb with an isotopic composition that causes the surface organic layer all over Europe to have lower (i.e., heavier) 206Pb/207Pb ratios that are coincidentally similar to anthropogenic Pb sources? No, of course not. In this comment the author explains why he thinks future studies should not adopt the conclusions of Reimann et al.

We present the results of nightglow observation of the atomic oxygen 557.7 nm line emission in the solar cycle 23. We use the experimental data obtained at Geophysical observatory near Irkutsk (52°N, 103°E), Russia, for the 1997–2006 period. The 557.7 nm emission observations data are compared with atmospheric and solar parameters. We note a difference in correlation coefficients between the 557.7 nm emission intensity and the solar activity indices in different phases of the solar cycle. Airglow observation results are compared with the observational data obtained by other authors. The obtained results show that the variations of 557.7 nm emission intensity are highly sensitive to atmospheric parameters and could be preliminary associated with the atmospheric dynamics and various disturbances including the effects from lower atmospheric layers. Probably, manifestation of these disturbances and their contribution to the 557.7 nm emission variations may differ in particular years or cycles of solar activity.

Results of estimation of radon ( Rn 222 ) emanation factors of the commonly used building materials in India are presented. All the samples were analyzed for Ra 226 , Th 232 and K 40 contents by gamma spectrometric method. Rn 222 mass exhalation rates of the various samples were determined using an Alphaguard, a continuous radon monitoring system. From the Ra 226 content and Rn 222 mass exhalation rate obtained, the Rn 222 emanation factor was evaluated for the samples. Results showed that the estimated Rn 222 emanation factors of the studied building materials and soil samples under dry condition and in powder form varied from 0.1% to 20.8 %.