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1.
ABSTRACT

The present study focuses on the elemental characterization of fine and coarse particles collected at a coastal site of southwestern Italy, in a suburban area of the Calabria region. A chemical tracer analysis was carried out to identify the major emission sources influencing on the atmospheric aerosol levels. Size-resolved particulate samples were collected during three 2-week seasonal sampling campaigns: autumn (19 October to 2 November 2003), winter (19 January to 2 February 2004) and spring (26 April to 10 May 2004). Ambient concentrations of selected elements (Fe, Mn, Mg, Ca, V, Cu, Cr, Ni, Zn, Pb, and Cd) associated to fine and coarse size fractions were determined using atomic absorption spectrometry (AAS). The enrichment factor method was applied, suggesting a prevailing anthropogenic component for all the detected elements, with Fe, Mg, Mn, and Ca as exceptions. Trajectory sector analysis was used in order to discriminate the influence of different air mass origins and paths. Long-range transport from both the continental Europe and the Saharan region proved to be the main influencing factors. African dust outbreaks, whose occurrence frequency was greater during the autumn and spring seasonal monitoring periods, gave rise to a total of eight exceedances of the European Commission (EC) PM10 daily limit value as well as an increase in values of the crustal-derived elements (Fe, Mg, and Ca). Long-range transport from the heavily industrialized area of Central/Eastern Europe contributed to the high levels of Zn, Cd, and Pb that were recorded during the winter sampling campaign. Seasonal trend and comparison with measurements previously performed across the Mediterranean basin were also presented and discussed.

IMPLICATIONS This paper, which investigates both natural and anthropogenic aerosol sources, contributes to the characterization of fine and coarse particles in a suburban area of the southern Italian region of Calabria whose air quality assessment is still being defined. The monitoring site involved in this study, located at the interface between continental Europe and the Mediterranean basin, offers an important platform to study the influence of seasonal meteorology and predominant circulation patterns on the aerosol concentration levels and their chemical composition.  相似文献   

2.
A joint project of government and industry people who studied the possible effect upon air pollution in Los Angeles of variations in the composition of gasoline sold in Los Angeles is discussed.

No experimental automotive test work was undertaken in this project. However, prototype fuel blends were made and analyzed in order to simulate the effects certain changes would have upon photochemical smog formation.

It is apparent from the results of this study that the potential of reducing smog in Los ngeles by fuel modifications is quite small, even in the year of maximum effect. This potential decreases to a negligible level due to the effectiveness of mechanical control of evaporative losses required in California starting with the 1970 model cars.  相似文献   

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The simple ATDL urban dispersion model Is based on the formula Xo(g/m3) = CO(g/m2s)/U(m/s). The diurnal variation of the stability factor C, which can be thought of as the width of the urban area divided by the vertical dispersion of the pollution cloud, has not before been satisfactorily estimated. Using observed diurnal variations of CO concentrations and traffic frequencies reported by DeMarrais of the EPA for many stations in the states of Maryland, New Jersey, and Colorado, and using wind data from these states, hourly values of C - XoU/Q were calculated. The ratio of C to the daily average C is found to equal about 2.5 at 4 a.m., drops to about 0.5 by 8 a.m., and remains at 0.5 until about 6 p.m.., when it starts to climb slowly again. Application of this new stability factor to independent CO data from Los Angeles yields correlations between measured and predicted concentrations of about 0.7.  相似文献   

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By their land use practices the agricultural and construction industries are unwittingly causing an increase in atmospheric pollution by aeroallergens such as ragweed pollen. This public health problem is discussed in the following four papers by an interdisciplinary team. Possible remedies are described.  相似文献   

7.
Numerous oxidant-injured ponderosa pine and other tree species have been detected in the lower elevation forests of the southern Sierra Nevada mountain range of California in the Sequoia National Forest, Sequoia-Kings Canyon National Parks, and on state and private lands. Affected pines were observed in a broad band following the many ridges that rise above the Central Valley floor to the 1900-2600 m elevation. Slight symptoms of ozone chlorotic mottle on ponderosa pine appeared from about 1000 m altitude, increased in severity as elevation increased and then diminished in severity above 2600 m. An apparent east to west gradient of disease was discovered; severity lessened as distance from the Central Valley increased. Atmospheric monitoring in three forested sites suggests that ozone occurs in doses sufficient to elicit symptoms of this widespread disease.  相似文献   

8.
Remote sensing is an extremely new science which developed from World War II technology. At that time, infrared sensitive film (false color) was used to detect such things as troop movements and camouflaged war materials. In essence, the film displayed a color contrast between the artificial and organic vegetation.  相似文献   

9.
One of the most annoying aspects of photochemical air pollution, particularly in the Southern California Air Basin, has been eye irritation. The most aggravating combination of driving in heavy traffic in Los Angeles, suffering from tearing and burning of the eyes together with very limited visibility, was a strong motivation for the public to demand that effective control actions be taken.  相似文献   

10.
This paper will discuss the sources of odorous air pollutants from sulfate pulping operations. One of the major sources is the recovery furnace. Odors from this source can be reduced considerably by oxidation of the black liquor prior to evaporation and burning. The procedure has been used with considerable success in the northwestern and northeastern parts of the United States. Unfortunately, the majority of sulfate pulp production occurs in areas where southern pine is the basic raw material. For several reasons the black liquor resulting from southern pine operations presents problems when the usual oxidation procedures are used. Although not as effective as normal black liquor oxidation strong black liquor can be oxidized without too much difficulty. Various procedures for oxidation of black liquor will be discussed. Results of stack sampling in U. S. pulp mills with and without the oxidation unit in operation will be reported.  相似文献   

11.
Abstract

Computational fluid dynamic (CFD) analysis of the thermal flow in the combustion chamber of a solid waste incinerator provides crucial insight into the incinerator’s performance. However, the interrelation of the gas flow with the burning waste has not been adequately treated in many CFD models. A strategy for a combined simulation of the waste combustion and the gas flow in the furnace is introduced here. When coupled with CFD, a model of the waste combustion in the bed provides the inlet conditions for the gas flow field and receives the radiative heat flux onto the bed from the furnace wall and gaseous species. An unsteady one-dimensional bed model was used for the test simulation, in which the moving bed was treated as a packed bed of homogeneous fuel particles. The simulation results show the physical processes of the waste combustion and its interaction with the gas flow for various operational parameters.  相似文献   

12.
Recently, various authors1–4 have indicated that a need exists to establish a uniform air pollution index for communities throughout the nation.Although the literature reveals several attempts to develop air pollution indices,5–7 none of these indices has received widespread acceptance by state and local air pollution control agencies, probably because none has received the active support or endorsement of the federal government. We now wish to report that significant progress has been made at the federal level toward the goal of a recommended national air pollution index.  相似文献   

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The use of multistage, dry, fluidized beds of continuously recycled, coal-based activated carbon appears technically and economically attractive for both adsorption of stack gas So2 and sequential conversion to elemental sulfur. Conceptual design details and economic factors are discussed for the treatment of power plant or oil refinery SO2 effluents with by-product sulfur recovery.  相似文献   

16.
The TR-l Research Committee of the Air Pollution Control Association conducted a survey during 1969–70 to determine what air pollution research problems require attention. All APCA committees were requested to contribute topics to this survey, especially within their area of activity. Other professional societies were contacted through liaison representatives of APCA. The responses to the survey have been reviewed, categorized, selected, and edited for inclusion in this report. Additional material and concepts have been contributed by members of the TR-l Committee.  相似文献   

17.
Air monitoring by the A.I.S.I. filter sampling device which both preceded and was concurrent with source control of particulates demonstrated air quality improvement over a ten-year period. A difference in improvement from that estimated by the pollution control agency resulted from difference in the measurement parameters.  相似文献   

18.
An urban air pollution incident, like a natural or man-made catastrophe, presents a crisis situation which can only be relieved if adequate contingency plans have been prepared in advance and an effective control organization is in a state of operational readiness to meet the threatened emergency. Although many air pollution incident control plans have been proposed in the past, most have remained in the conceptual or theoretical stages of preparation, because the relative infrequency of serious urban air pollution crises and the disruptive nature of major emission control operations tend to limit the opportunities available for field testing of these plans. In this respect, air pollution incident control planning is analogous to strategic planning for a military operation, where the only completely legitimate test of a strategy is applied on the battlefield. In order to accomplish the transition from conceptual planning to a practical, operational field strategy for air pollution incident control, a program of incident control tests has been initiated in Chicago. These field tests, which use the city as a laboratory for the development of control strategies, are analogous to a series of military war games in which communication systems, command and control organizational structures, personnel roles, surveillance and monitoring equipment, control resources and pollution source controllability are tested under conditions which approximate as closely as possible the situation which prevails during an actual air pollution incident. This paper discusses the evolution of an incident control strategy from an initial, fixed response emission control exercise, through a meteorologically initiated control test to a fairly realistic war game series which is still developing.  相似文献   

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Most air pollution control programs rest on one or more of the following four basic philosophies: emission standards, air quality standards, emission taxes, and cost benefit analysis. Frequently they rest on mixtures or combinations of these four. This paper examines each of the four separately, tries to show why each is different from the others, and compares their advantages and disadvantages.  相似文献   

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