Stoffströme von Benzol unter besonderer Berücksichtung der Bundesrepublik Deutschland

In the Federal Republic of Germany, benzene is one of the most important basic materials for the chemical industry. Only a relatively small proportion of the pure benzene processed in the chemical industry is emitted into the environment (ca. 40t in 1991). But the substance is also a natural component of the crude oil in gasoline and is released during incomplete combustion or is formed out of other aromatic substances. The primary source of emissions, with more than 10,000 t/yr (approximately 85% of this from motor vehicles with Otto engines), is commercial motor vehicle transportation. Benzene concentrations in the environment are approximately <1 μg/m³ in rural areas, 20–30 μg/m³ near main roads (peak levels in highly urbanized regions with much traffic as high as approximately 100 μg/m³) and 7–15 μg/m³ in the vicinity of industrial polluters. It has not been possible to detect a specific trend over time during the last ten years. An increased exposure (approx. 350–27,000 μg/m³) is likely while filling the tank and within the motor vehicle (approx. 10–200 μg/m³) due to gasoline volatilization from pipes, etc. Compared to outdoor air, higher concentrations of benzene (approx, 2–11 μg/m³) are measured in the indoor air which contains additionally benzene from tobacco smoke, equipment, renovating work and heating. The primary exposure pathway of benzene in humans is inhalation. Apart from individuals with occupational exposure, smokers have the highest internal benzene burden. Measures undertaken during recent years to reduce the amount of emissions have been counteracted at least in part by the increase in motor vehicle traffic. Further measures to reduce the emissions or to change the transporttation policies must still be or have already been initiated.     

PM2.5: global progress in controlling the motor vehicle contribution

It is well established that ambient particles in the size range of 2.5 microns or less case a wide variety of adverse health effects. According to a recent study from the World Health Organization, in 2010 these effects resulted in approximately 3.2million premature deaths with vehicles being one of the significant contributors. Diesel vehicle particulate emissions which are virtually all smaller than 2.5 microns raise additional special concerns due to their carcinogenicity and high ratio of black carbon （BC） to organic carbon; black carbon has recently been found to be the second most important contributor to climate change after carbon dioxide. Other pollutants emitted by diesels and other vehicles such as the oxides of nitrogen and volatile organic compounds also contribute to ambient particulate matter smaller than 2.5 microns in size （PM2.5） after undergoing secondary transformations in the atrno- sphere. Technologies have dramatically reduce vehicle been developed that can emissions when clean, low sulfur fuels are available and these technologies are being phased in throughout the industrialized world resulting in a global decrease in particulate matter （PM） and BC emissions from vehicles. However the vehicle population is growing rapidly in the developing world, leading to increases in emissions in many countries. Unless these rapidly industrializing countries move to state of the art vehicles and clean fuels, global PM, BC and NOx emissions from road vehicles will start to turn up over the next 10 to 15 years.     

Development of source profiles and their application in source apportionment of PM<Subscript>2.5</Subscript> in Xiamen,China

Ambient PM_2.5 samples were collected at four sites in Xiamen, including Gulangyu (GLY), Hongwen (HW), Huli (HL) and Jimei (JM) during January, April, July and October 2013. Local source samples were obtained from coal burning power plants, industries, motor vehicles, biomass burning, fugitive dust, and sea salt for the source apportionment studies. The highest value of PM_2.5 mass concentration and species related to human activities (SO₄ ^2–, NO₃ ^–, Pb, Ni, V, Cu, Cd, organic carbon (OC) and elemental carbon (EC)) were found in the ambient samples from HL, and the highest and lowest loadings of PM_2.5 and its components occurred in winter and summer, respectively. The reconstructed mass balance indicated that ambient PM_2.5 consisted of 24% OM (organic matter), 23% sulfate, 14% nitrate, 9% ammonium, 9% geological material, 6% sea salt, 5% EC and 10% others. For the source profiles, the dominant components were OC for coal burning, motor vehicle, biomass burning and sea salt; SO₄ ^2– for industry; and crustal elements for fugitive dust. Source contributions were calculated using a chemical mass balance (CMB) model based on ambient PM_2.5 concentrations and the source profiles. GLY was characterized by high contributions from secondary sulfate and cooking, while HL and JM were most strongly affected by motor vehicle emissions, and biomass burning and fugitive dust, respectively. The CMB results indicated that PM_2.5 from Xiamen is composed of 27.4% secondary inorganic components, 20.8% motor vehicle emissions, 11.7% fugitive dust, 9.9% sea salt, 9.3% coal burning, 5.0% biomass burning, 3.1% industry and 6.8% others.

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交通污染区城市绿化植物硫含量分布

为探讨城市绿化植物对交通环境中SO2的响应，以远离城市道路的相对清洁区公园生长的植物为对照植物，采集了广东省被广泛栽种的18种园林绿化植物的不同方位的叶片和树皮样品，用硫酸钡比浊法测定了每种植物样品在交通污染区面向机动车行驶方向、面向人行道方向及相对清洁区的植物样品等不同方位的植物叶片和树皮硫含量，分析了绿化植物在同一株植物的不同生长部位和不同环境中硫含量的分布特征。结果表明，交通污染区所有样品的叶片硫和树皮硫含量均高于相对清洁区的样品。其中，远离工厂的交通污染区生长的同一株植物，离机动车道越近，硫含量越高；靠近工厂的交通污染区的同一植物，离工厂近的部位的植物树皮硫含量高于面向机动车道一侧的植物硫含量。     

The effects of license plate-based driving restrictions on air quality: Theory and empirical evidence

A typical driving restriction prohibits drivers from using their vehicles on given weekdays, based on the last digits of their vehicles’ license plates. A number of cities in developing countries have used license plate-based driving restrictions as a policy for reducing urban air pollution and traffic congestion. This paper develops a theoretical model of the effects of license plate-based driving restrictions on air quality that combines an economic model with information about the sources and atmospheric chemistry of different air pollutants. We then draw upon suggestive empirical evidence from license plate-based driving restrictions implemented in Bogotá, Colombia. Consistent with our theory model, we find suggestive empirical evidence that under certain circumstances, due to substitution, the purchase of a second car, the use of alternative modes of transportation, and/or atmospheric chemistry, it is possible for license plate-based driving restrictions to increase air pollution. Also consistent with our theory, we find that license plate-based driving restrictions may have different effects on different air pollutants, reflecting heterogeneity in the sources and atmospheric chemistry of the pollutants. In particular, owing to atmospheric chemistry, it is possible for a license plate-based driving restriction to cause a significant decrease in NO and a significant increase in NO₂, NO_x, and O₃.     

Life cycle analysis and choice of natural gas-based automotive alternative fuels in Chongqing Municipality, China

Road transport produces significant amounts of emissions by using crude oil as the primary energy source. A reduction of emissions can be achieved by implementing alternative fuel chains. The objective of this study is to carry out an economic, environmental and energy (EEE) life cycle study on natural gas-based automotive fuels with conventional gasoline in an abundant region of China. A set of indices of four fuels/vehicle systems on the basis of life cycle are assessed in terms of impact of EEE, in which natural gas produces compressed natural gas (CNG), methanol, dimethylether (DME) and Fischer Tropsch diesel (FTD). The study included fuel production, vehicle production, vehicle operation, infrastructure and vehicle end of life as a system for each fuel/vehicle system. A generic gasoline fueled car is used as a baseline. Data have been reviewed and modified based on the best knowledge available to Chongqing local sources. Results indicated that when we could not change electric and hydrogen fuel cell vehicles into commercial vehicles on a large scale, direct use of CNG in a dedicated or bi-fuel vehicle is an economical choice for the region which is most energy efficient and more environmental friendly. The study can be used to support decisions on how natural gas resources can best be utilized as a fuel/energy resource for automobiles, and what issues need to be resolved in Chongqing. The models and approaches for this study can be applied to other regions of China as long as all the assumptions are well defined and modified to find a substitute automotive energy source and establish an energy policy in a specific region.     

Environmental aspects of biofuels in road transportation

Energy is a vital and growing need for human activities such as transport, agriculture and industry. The transport and agriculture sectors are major consumers of fossil fuel. However, availability of fossil fuels is limited. The use of fossil fuels is of increasing environmental concerns because it produces toxic airborne particulates and greenhouse gases such as CO₂. The increasing industrialization and motorization of the world led to a steep rise for the demand of petroleum-based fuels. Hence, it is necessary to seek alternative fuels, which can be produced from resources available locally within the country such as alcohol, biodiesel and vegetable oils. Biodiesel is defined as the mono alkyl esters of vegetable oils or animal fats. Biodiesel is the best candidate for diesel fuels in the diesel engines. The advantage of biodiesel over gasoline and petroleum/diesel is its eco-friendly nature. This article reviews the production, characterization and current status of biofuels mainly biodiesel along with the environmental impacts of particulate matter, greenhouse gas emissions originated from biodiesel.     

美国汽车清洁燃料研究发展

本文简要介绍了美国汽车清洁燃料和汽油替代燃料的研究和发展状况，内容涉及美国政府对发展汽车清洁燃料的战略、政策、立法和有关发展计划，清洁燃料的类型和种类及应用情况，以及存在的主要问题和未来的发展方向。     

Effects of Road Fencing on Population Persistence

Abstract:  Roads affect animal populations in three adverse ways. They act as barriers to movement, enhance mortality due to collisions with vehicles, and reduce the amount and quality of habitat. Putting fences along roads removes the problem of road mortality but increases the barrier effect. We studied this trade-off through a stochastic, spatially explicit, individual-based model of population dynamics. We investigated the conditions under which fences reduce the impact of roads on population persistence. Our results showed that a fence may or may not reduce the effect of the road on population persistence, depending on the degree of road avoidance by the animal and the probability that an animal that enters the road is killed by a vehicle. Our model predicted a lower value of traffic mortality below which a fence was always harmful and an upper value of traffic mortality above which a fence was always beneficial. Between these two values the suitability of fences depended on the degree of road avoidance. Fences were more likely to be beneficial the lower the degree of road avoidance and the higher the probability of an animal being killed on the road. We recommend the use of fences when traffic is so high that animals almost never succeed in their attempts to cross the road or the population of the species of concern is declining and high traffic mortality is known to contribute to the decline. We discourage the use of fences when population size is stable or increasing or if the animals need access to resources on both sides of the road, unless fences are used in combination with wildlife crossing structures. In many cases, the use of fences may be beneficial as an interim measure until more permanent measures are implemented.     

Fuel Economy and Motor Vehicle Emissions

The conventional wisdom is that there is no relationship between fuel economy and motor vehicle emissions, at least for new cars. The requirement that all vehicles meet a common emission standard in terms of grams per mile effectively breaks whatever link there might have been between fuel economy and emissions in uncontrolled (preregulatory) vehicles. As cars age, however, the emission control equipment tends to break down, providing reason to think that the conventional wisdom might do the same. This paper reports on an empirical examination of this proposition, by linking EPA fuel economy certification data to a large database of motor vehicle emission measurements collected by remote sensing. It is found that better fuel economy is strongly associated with lower emissions of CO and HC and that the effect gets stronger as vehicles age.     

Impact of gasoline engine deposits on light duty vehicle emissions: in-use case study in Beijing, China

Tailpipe emissions from light-duty gasoline vehicles usually deteriorate over time. The accumulation of engine deposits due to inadequate gasoline detergency is considered to be one of the major causes of such emission deterioration. Six in-use light-duty gasoline vehicles in Beijing were tested to investigate the impact of engine deposits on emissions of hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NO _x ). Emissions under cold start and hot running test conditions from the six light duty vehicles were measured before and after engine deposits were removed. Results show that although individual vehicles reacted differently for each of the pollutants, elimination of engine deposits on average reduced HC emissions under hot running conditions by 29.4%, CO emissions under cold start conditions by 23.0% and CO emissions under hot running conditions by 35.5% (t < 0.05 in all cases). No pollutant emissions increased with statistical significance (t < 0.05) after the removal of engine deposits. Variations of emission changes upon removal of engine deposits were observed. Such variations are in line with previous studies, implying that the impact patterns of engine deposits on vehicle emissions may be subject to many influencing factors that are not fully understood and difficult to control under all conditions. A statistical view of the impact of engine deposits on vehicle emissions may be appropriate for evaluation of emissions reductions across a city or a country. It is necessary to maintain sufficient and effective gasoline fuel detergency in practice to keep the engines clean and in turn reduce vehicle emissions.     

Compression of home ranges in ghost crabs on sandy beaches impacted by vehicle traffic

Animal movement is a pivotal element of many ecological processes, and on ocean-exposed sandy shores, ghost crabs (genus Ocypode) undertake extensive nocturnal forays on the beach surface. Because crab populations are also threatened by vehicle traffic, indicators that can detect sublethal effects before population declines are manifest are important. To this end, we tested on a barrier island in Eastern Australia whether movement patterns of crabs respond predictably to disturbance by vehicles; this was done by tracking (using the spool-and-line technique) crabs at night in beach sections open and closed to traffic. Beach traffic not only halved population densities of crabs on the unvegetated beach seawards of the dunes, but it also fundamentally changed crab behaviour and movement: individuals from beach areas rutted by tyre tracks travelled shorter distances in a more erratic zigzag pattern, and they had significantly compressed home ranges. Such behavioural changes linked to human pressures could be well suited as an early warning signal for wider negative ecological impacts (as demonstrated by reduced abundances). They also emphasize the need to incorporate sublethal effects into the assessment and management of ecological changes resulting from beach recreation.     

Troposphärisches Ozon: Entstehung, Konzentrationsvariabilität und Wirkung unter dem Gesichtspunkt der Ozonminderung

This paper is an attempt to summarise and critically assess our knowledge on the formation, variation in concentrations and impact of ozone under the aspect of abatement strategies. The present ozone budget is determined to about 50% through human activities where methane and carbon monoxide contribute more than 80% to ozone formation. This “residual” or “background” ozone determines the annual mean ozone concentration. Due to the long time period (months and years) required for CH₄ and CO oxidation, both compounds do not contribute to the excessive ozone concentrations often found in the summer. Moreover, the increase in tropospheric ozone is becoming a global problem. Because emissions of CH₄ and CO are increasing globally, the “background” ozone will also increase in the future. Non-methanehydrocarbons (NMHC) may produce O₃ within a few days because of their high reactivity concerning oxidants. For photochemical O₃ formation, the source-sink budget has to be taken into account for making an estimation of the net ozone formation. Ozone accumulation only occurs when the removal potential (especially heterogeneous processes within clouds, but also a reduction in the net photochemical formation) of the air mass is small. This “excess” ozone has been reduced successfully within the last decade, most likely as a result of automobile catalyst use. An impact of O₃ on humans has been found only for concentrations >100 ppb. Thus, O₃ should not be a problem for people. Although vegetation is much more sensitive (esp. conifers), it is not possible to present reliable thresholds at present. There is evidence that the dose (accumulation exposure) is an important criterion. Therefore, a mean annual concentration which may possibly be increasing further should be the target of air pollution controls. Former measures and ideas of ozone controlling have no usefulness in this sense.     

Is there really a green paradox?

In the absence of a CO₂ tax, the anticipation of a cheaper renewable backstop increases current emissions of CO₂. Since the date at which renewables are phased in is brought forward and more generally future emissions of CO₂ will decrease, the effect on global warming is unclear. Green welfare falls if the backstop is relatively expensive and full exhaustion of fossil fuels is optimal, but may increase if the backstop is sufficiently cheap relative to the cost of extracting the last drop of fossil fuels plus marginal global warming damages as then it is attractive to leave more fossil fuels unexploited and thus limit CO₂ emissions. We establish these results by analyzing depletion of non-renewable fossil fuels followed by a switch to a clean renewable backstop, paying attention to timing of the switch and the amount of fossil fuels remaining unexploited. We also discuss the potential for limit pricing when the non-renewable resource is owned by a monopolist. Finally, we show that if backstops are already used and more backstops become economically viable as the price of fossil fuels rises, a lower cost of the backstop will either postpone fossil fuel exhaustion or leave more fossil fuel in situ, thus boosting green welfare. However, if a market economy does not internalize global warming externalities and renewables have not kicked in yet, full exhaustion of fossil fuel will occur in finite time and a backstop subsidy always curbs green welfare.     

Is there really a green paradox?

In the absence of a CO₂ tax, the anticipation of a cheaper renewable backstop increases current emissions of CO₂. Since the date at which renewables are phased in is brought forward and more generally future emissions of CO₂ will decrease, the effect on global warming is unclear. Green welfare falls if the backstop is relatively expensive and full exhaustion of fossil fuels is optimal, but may increase if the backstop is sufficiently cheap relative to the cost of extracting the last drop of fossil fuels plus marginal global warming damages as then it is attractive to leave more fossil fuels unexploited and thus limit CO₂ emissions. We establish these results by analyzing depletion of non-renewable fossil fuels followed by a switch to a clean renewable backstop, paying attention to timing of the switch and the amount of fossil fuels remaining unexploited. We also discuss the potential for limit pricing when the non-renewable resource is owned by a monopolist. Finally, we show that if backstops are already used and more backstops become economically viable as the price of fossil fuels rises, a lower cost of the backstop will either postpone fossil fuel exhaustion or leave more fossil fuel in situ, thus boosting green welfare. However, if a market economy does not internalize global warming externalities and renewables have not kicked in yet, full exhaustion of fossil fuel will occur in finite time and a backstop subsidy always curbs green welfare.     

A study on traffic noise of two campuses of University, Balasore, India

Noise pollution is a significant environmental problem in many rapidly urbanizing areas of Orissa, India. Transportation sector is one of the major contributors to noise in these areas. The present study is an attempt to estimate traffic noise pollution at five places on the way from Vyasa Vihar Campus to Gyan Vigyan Vihar Campus of Fakir Mohan University, Balasore, Orissa. The sources of noise at the studied sites are predominantly attributable to motor vehicular traffic. The noise levels of all the five locations were found to be beyond permissible limit during the day time. The contributions of different types of vehicles to environmental noise were found to ranging from 70.4-94.2, 79.0-96.1, 77.8-110.2, 70.8-90.3, 71.0-87.5, 71.1-84.4, 72.5-86.9 and 74.0-85.4 dB (A) by cargo carrying Trucks, Tractors, Dumpers, Town Buses, Motor cycles, Bolero/Trucker, Pick up and Tempo respectively. The contributions of individual vehicles towards noise pollution were found to be more than the road traffic noise-limit i.e., 70 dB (A). On certain local inhabitants interviewed, the impact of noise was observed in the forms of alterations in their physical, psychological and personal aspects. This study warrants attention from all sections of people to deal with the problem of noise pollution.     

Does pyrogenicity protect burning plants?

Pyrogenic plants dominate many fire-prone ecosystems. Their prevalence suggests some advantage to their enhanced flammability, but researchers have had difficulty tying pyrogenicity to individual-level advantages. Based on our review, we propose that enhanced flammability in fire-prone ecosystems should protect the belowground organs and nearby propagules of certain individual plants during fires. We base this hypothesis on five points: (1) organs and propagules by which many fire-adapted plants survive fires are vulnerable to elevated soil temperatures during fires; (2) the degree to which burning plant fuels heat the soil depends mainly on residence times of fires and on fuel location relative to the soil; (3) fires and fire effects are locally heterogeneous, meaning that individual plants can affect local soil heating via their fuels; (4) how a plant burns can thus affect its fitness; and (5) in many cases, natural selection in fire-prone habitats should therefore favor plants that burn rapidly and retain fuels off the ground. We predict an advantage of enhanced flammability for plants whose fuels influence local fire characteristics and whose regenerative tissues or propagules are affected by local variation in fires. Our "pyrogenicity as protection" hypothesis has the potential to apply to a range of life histories. We discuss implications for ecological and evolutionary theory and suggest considerations for testing the hypothesis.     

Research of usability of tree leaves and soil in determining the contribution of industry and traffic to air pollution in Bozüyük (Turkey) region

In industrialized regions like Bozüyük, generally density of settlement and traffic is also observed. As a result of this density, the metal pollution that results from either industrial activities or traffic shall affect the air quality negatively. In determining this effect and sources thereof inspection of the depositing of heavy metals, which cause pollution, on the tree leaves and in the soil, and making comments by comparing with the values in the same kinds of plants and soil in the clean region has been aimed. For this purpose, zinc, copper, chromium, cadmium, iron, nickel, lead analysis have been carried out in order to determine the accumulation of pollution in plants and soils resulting from heavy industry and vehicles around Bozüyük (Turkey) region which is close to highway. These analyses have been carried out on washed and unwashed tree leave samples and surface soil from ten locations. Data used in the results were the average values of a series of data obtained from the experimental studies.     

Minderung von Lärmimmissionen des Kfz-Verkehrs

Although the permissible emission limits for new motor vehicles are continuously being reduced year after year, the proportion of citizens in the Federal Republic of Germany who are affected by such traffic noise continues to remain practically constant. Thus, aside from the innovations in motor-vehicle technology, the question must be raised concerning what other possibilities are actually available for achieving a reduction in the emission of traffic noises. In the following, planning possibilities are presented for the traffic routes themselves and for their direct vicinities. An evaluation is also made concerning their efficiency. In addition to the prognostic tools of the guidelines which have been introduced in Germany and Austria, the application of modern research must also be taken into consideration.     

The impact on tropospheric ozone formation on the implementation of a program for mobile emissions control: a case study in São Paulo,Brazil

The main sources of reactive hydrocarbons (RHC) and nitrogen oxides (NO_x), ozone precursors, in the Metropolitan Area of São Paulo (MASP) in the southeast of Brazil are emissions from vehicles fleets. Ambient surface ozone and particulate matter concentrations are air quality problem in the MASP. This study examined the impact that implementing a control program for mobile emissions has on ozone concentrations, An episode of high surface ozone concentrations occurring in the MASP during the March 13–15, 2000 period was used as a case study that was modeled for photochemical oxidants using the California Institute of Technology/Carnegie Mellon University three-dimensional photochemical model. Different scenarios were analyzed in relationship to the implementation of the Programa Nacional de Controle de Poluição por Veículos Automotores (PROCONVE, National Program to Control Motor Vehicle Pollution). Scenario 1 assumed that all vehicles were operating within PROCONVE guidelines. Scenarios 2 and 3 considered hypothetical situations in which the PROCONVE was not implemented. Scenario 2 set the premise that vehicles were using pre-1989 technology, whereas scenario 3 allowed for technological advances. A base case scenario, in which the official emission inventory for the year 2000 was employed, was also analyzed. The CIT model results show agreement with most measurements collected during 13–15 March 2000 modeling episode. Mean normalized bias for ozone, CO, RHC and NO _x are approximately 9.0, 6.0, ?8.3, 13.0%, respectively. Tropospheric ozone concentrations predicted for scenario 2 were higher than those predicted for scenarios 1, 3 and base case. This study makes a significant contribution to the evaluation of air quality improvement and provides data for use in evaluating the economic costs of implementing a program of motor vehicle pollution control aimed at protecting human health.