Pollutant Budgets Research Articles

Vertical exchange and regional budgets of air pollutants over densely populated areas

Process parameters of photochemical smog formation are derived and vertical exchange between the boundary layer and the free troposphere is identified as an important transport contribution. The analysis is based on three-dimensional observations with aircraft measurements as a key contribution. The information is needed to supplement and validate numerical model results. The wind and concentration fields are reconstructed from the measurements and the fluxes into and out of a closed box are calculated. The flux budgets give net export rates for the box. In addition, a net accumulation rate and a lower limit to the fraction of locally produced pollution are obtained. The accumulation rate comprises net chemical production plus deposition for the secondary pollutant ozone. In case of primary pollutants such as NO x , local emissions also contribute to this accumulation rate. Six diverse areas are compared: Swiss Plateau, Vienna, Berlin, Heilbronn, Ticino Region and Hong Kong. Typical net production rates for ozone are between 2.5 and 3.5 ppb h -1 in the afternoon. Fresh local production contributes between 5 and 30% to the observed ozone, while the remainder is advected or is already present. Berlin, as a fairly isolated urban area in a rural environment, has the highest fraction of “homemade” pollution. Over Hong Kong, strong local NO x emissions hinder significant net ozone production in the vicinity of the urban center, but enhanced ozone production occurs further downwind. Budgets of the primary pollutant NO 2 are much more dependent on the regional emission situation. The corresponding fractions of “homemade” NO 2 pollution are higher than for O 3 and typically between 30 and 100%. An exception is the Ticino Region which imports large amounts of pollutants from highly industrialized northern Italy. Vertical exchange between the atmospheric boundary layer and the free troposphere contributes substantially to the regional pollutant budget. It dominates the budget when horizontal pollutant gradients across the box are absent or weak, as over the heterogeneous Swiss Plateau. The vertical flux can be calculated directly from the high-resolution aircraft measurements over Switzerland and Hong Kong using the eddy correlation method. A statistical model is developed to describe the fluxes as a function of the concentration gradients, the potential temperature and the wind profiles. This model is then used for the cases without high-resolution aircraft measurements (Vienna, Berlin and Heilbronn).

The FLAME Project: General Discussion and Conclusions

Detailed discussion of the FLAME data at individual country level is included in other papers in this volume but some aspects of the analyses and data interpretation are best discussed on a broader level and that is the aim of this paper. The spatial distribution of fly-ash particles in the participating countries shows good agreement with expected sources and this implies that the majority of particulates travel less than 100 km from their source although lower concentrations of particles were detected at all sample sites. Areas of elevated concentration mostly coincide with population centres and imply possible impacts on human health by fine particulates (e.g. PM10) from fossil-fuel sources in these areas. Problems with the particle characterisation, developed within the FLAME project, include difficulties in allocation due to the overlap between coal-series fuels and the presence of a 'mineral coal' background at lake sites thought to be due to persistent sediment minerals surviving the chemical pre-treatment and becoming allocated to coal. This leads to implications for the inclusion of further fuels into the classification and the application of the technique to the same fuels beyond Europe. The combination of lake sediment SCP data and sediment and moss metals data can also provide an indication of the impact from anthropogenic contamination at a site and probable source types. Comparison with previous moss analyses from 1990 show that metal concentrations in central Europe may have decreased but levels in the UK have shown little change. Finally, comparisons of FLAME data with the EMEP model for pollutant budgets across Europe generally show good agreement for pathways, although further work is needed in receptor countries for additional confirmation.

Transport of air pollutants from the boundary layer to the free tropospere over complex terrain

Transport of trace gases from the atmospheric boundary layer (ABL) to the free troposphere (FT) is negligible under cloudless conditions over uniform terrain. However, over complex topography, an instantaneous exchange between the structured and discontinuous ABL and the FT may be possible. Aircraft measurements at the ABL - FT transition zone reveal pollutant fluxes larger than could be expected from an one-way entrainment. Those fluxes significantly influence regional pollutant budgets. Above populated areas and under high insolation, flux of O 3 and NO 2 is usually directed from the ABL to the free troposphere, where the overall tropospheric ozone production is altered. The exchange with the free troposphere is examined for two mesoscale areas: The Swiss Plateau in Switzerland and the Hong Kong area in Asia. The Swiss Plateau exhibits mainly hilly terrain while the Hong Kong area displays a very complex terrain with sea surfaces as well as steep mountains. The flux across the top of the ABL is obtained from high resolution airborne measurements taken by the NCAR King Air. A flux partitioning is performed to identify the most important atmospheric scales contributing to this vertical transport. Turbulent transport is important for the Swiss Plateau as well as Hong Kong. Over Hong Kong, larger scales also contribute significantly to vertical exchange. This larger scale transport might indicate that local thermotopographic circulations are involved. A statistical model based upon the measurements over the Swiss Plateau allows a rough estimation of the vertical flux densities from the concentration, potential temperature and windshear profiles for cases where high resolution airborne measurements are not available.

Pollutant transport over complex terrain: Flux and budget calculations for the pollumet field campaign

Especially over complex terrain, transport processes dominate the local pollutant concentrations observed. The data gathered during the POLLUMET measuring campaign in 1993 allow a quantitative analysis of the pollutant fluxes and the pollutant budgets. The data include airborne measurements by NCAR's King Air, radio soundings, radar wind profiles, and data from meteorological ground stations. The regions of interest were the rather densely populated Swiss Plateau, which is embedded between the Alps and the Jura Mountains, and a box south of the Alps covering the south Ticino region and parts of northern Italy. An interpolation scheme was developed to reconstruct the wind field from all available measurements. From the wind field and the reconstruction of the concentration field the fluxes into and out of a box with fixed boundaries are calculated. The pollutant budgets are obtained from the sum of the fluxes and considering a mean vertical velocity. To assess the uncertainties introduced through the interpolation of the measurements, an extensive sensitivity analysis is included. The Swiss Plateau exports ozone and nitrogen oxides. The export rates can be interpreted as an ozone accumulation or fraction of ‘homemade pollution’ between 3 and 10% and require a net production rate of 1–2 ppb h −1. Accumulation of nitrogen oxides amounts to 20–60%. The box south of the Alps imports polluted air from northern Italy. Thus, oxidized nitrogen is not exported but a net production of ozone still occurs at a rate of 1–2 ppb h −1. The interpolated flow and concentration fields are decomposed into the mean over a box-boundary and the deviation from that mean. This allows isolation of the contribution of local circulations and large-scale turbulence to the total flux. It is shown how the local thermotopographic circulations increasingly dominate the transport as typical Alpine topography is approached. Even over the Swiss Plateau, approximately 20 km away from Alpine topography, coherent structures with a scale of 2–20 km contribute to the transport, which occurs mainly with the mean wind, however.

Pollutional aspects of gross solids and their interaction with sewer sediments

This paper describes a study programme underway in the upper Perth Road catchment in Dundee to estimate the effect of gross solids and their interaction with the sediment found within a combined sewer network. Gross solids have been collected at three different sites in the study catchment, near its head, at the catchment outfall and at an intermediate site. In conjunction with the study of gross solids, sewer sediment samples were collected and analysed to determine both their chemical and physical characteristics. The study also includes flow sampling (both dry and storm) and gully discharge monitoring. The pool of pollutants information thus collected includes surface derived, foul flow and gross solids pollutant characteristics. The objective of the study programme is to analyse the contribution made from the various inputs and to produce a budget of pollutants within the study sewer system. A description of the field and laboratory work undertaken in the study is described, together with a preliminary assessment of the pollutants budget technique.

Pollutional aspects of gross solids and their interaction with sewer sediments

This paper describes a study programme underway in the upper Perth Road catchment in Dundee to estimate the effect of gross solids and their interaction with the sediment found within a combined sewer network. Gross solids have been collected at three different sites in the study catchment, near its head, at the catchment outfall and at an intermediate site. In conjunction with the study of gross solids, sewer sediment samples were collected and analysed to determine both their chemical and physical characteristics. The study also includes flow sampling (both dry and storm) and gully discharge monitoring.The pool of pollutants information thus collected includes surface derived, foul flow and gross solids pollutant characteristics. The objective of the study programme is to analyse the contribution made from the various inputs and to produce a budget of pollutants within the study sewer system.A description of the field and laboratory work undertaken in the study is described, together with a preliminary assessment of the pollutants budget technique.

Atmosphere, climate, and change

This book, pat of the Scientific American Library series, seeks to provide the educated reader with a thorough sense of the scientific understanding of the major global environmental issues involving changes in the climate and in atmospheric chemistry. The eight chapters cover the following topics: introduction to the earth system; agents of climate including radiation energy, water budget, atmospheric circulation, and atmospheric transport of pollutants; chemistry in the air; climates of the past; changing chemistry; predicting the near future; predicting the far future; change and sustainability.

Long-range atmospheric transport of toxaphene to Lake Baikal

Complex mixtures of chlorinated bornanes and bornenes (CHBs), typically referred to as toxaphene or polychlorinated camphenes, were measured in the air and surface water of Lake Baikal, Russia during June, 1991. The mean CHB concentration was 16 ± 4 pg m −3 in air and 64 ± 37 pg/L in water. Levels in air were similar to previous measurements in Arctic regions, and the chromatographic pattern of CHB congeners was extremely “weathered” compared to a toxaphene standard suggesting long-range atmospheric transport rather that a nearby source. The congener pattern in the water samples was similar to that in the air indicating the importance of atmospheric deposition processes to Lake Baikal. Estimates of gas flux of CHBs across the air-water interface predict that this process could cause a substantial contribution to the lakes' overall pollutant budget.

Lead-210 sedimentation in Lake Ontario

The sedimentation rates and diffusive sediment mixing coefficients at several Lake Ontario locations have been derived from measurements of unsupported210Pb profiles in sediment cores. The values of mixing coefficients obtained in the present study are significantly lower than those obtained previously through an analysis of porosity profiles. The present estimates, however, are consistent with the rather well-preserved pollutant profiles at some of these locations. It is observed that the more realistic value of the mixing coefficient, obtained by inclusion of the sedimentation rate parameter, follows the sign opposite to that for the constant obtained by regression analysis of the porosity data. Further work is required to delineate this apparent relationship between two important physical characteristics of deposited sediments.Analysis of available suspended sediment data shows that Niagara River supplies about 1.8 million tonnes of sediment annually to Lake Ontario. This value is significantly lower than that (4.6 mt/yr) used previously in constructing sediment and pollutant budgets for Lake Ontario. From the presently derived sedimentation rate and suspended solid discharge estimates, an average value of 441 km2 (range 220-938 km2) is obtained for the minimum area of Lake Ontario over which the Niagara River-supplied fine sediment is deposited.

Water, nutrient and pollutant budgets in damaged Norway spruce stands in NE-Bavaria (F.R.G.) and their changes after different fertilization treatments

Water budgets and ecosystem balances of the main nutrients and pollutants were calculated in two Norway spruce forests at different states of decline in the Fichtelgebirge (F.R.G.) from summer 1984 through summer 1986. For that purpose, samples of precipitation, throughfall, litter seepage and soil solution were gathered weekly. Fluxes of main cations and anions were calculated by multiplying water fluxes through the different compartments with the appropriate ion concentrations. Both spruce stands are characterized by a sufficient water supply throughout the investigation period caused by high annual precipitation. Only in dry periods drastical restriction of plant available water may endanger those spruces growing on very stony podzols and cambisols. The calculation of deposition fluxes differentiates the damaged and the apparently healthy spruce stand. Input of SO2 and H+ as well as canopy buffering and K-leaching of the canopies are significantly higher in the damaged spruce stand than in the healthy one. Additionally, the exchangeable base cation content of the soil on the damaged site is nearly exhausted and therefore buffering capacity in the soil differs from those of the healthy site. There was a low increase of N03-leaching with seepage after the fertilization with high amounts of lime.

Use of trialkylamines as an indicator of urban sewage in sludges, coastal waters and sediments

Coastal areas receive a variety of land-based organic inputs, both natural and synthetic. The identification of specific organic markers in different marine compartments may be used to trace the pathways of transport, the regions of concentration and the short-term effects of such inputs into the ocean. Particular attention is being devoted to the assessment of urban wastes at coastal areas because of the environmental implications of discharging large quantities of urban sewage waters or sludges into the sea. Here we report the widespread occurrence of trialkylamines (TAMs) in coastal areas, originating from such sewage discharges. The concentrations of these compounds—which have the formula R1R2NCH3, where R1 = CH3 or CnH2n+1 and R2= CnH2n+1 for n = 14–18—in Western Mediterranean and North Sea coastal sediments (Fig. 1) ranged from 0.1 to 35 μgg−1 depending on the distance from and the pollutant budget of the urban sewage sources. We have identified TAMs as trace impurities in quaternary ammonium salts used as fabric softeners in household laundry detergents, for which reason they are found in urban sewage waters, primarily associated with the particulate phase. They correlate in the sedimentary record with other domestic surfactant markers, such as the long-chain alkylbenzenes (LABs). We propose, therefore, that TAMs may serve as conservative indicators of urban sewage contamination of coastal areas.

Budget of organic and inorganic pollutants in the doñana national park (Spain)

We report here an assessment of sources and inputs of organic and inorganic pollutants to the Doñana National Park (SW Spain), one of the finest wetlands in Europe. In the absence of local pollution sources, the occurrence and distribution of heavy metals (Zn, Cu, Pb), organochlorine compounds (DDT and PCBs) and hydrocarbons (both natural and anthropogenic) in different biotic and abiotic compartments of the park are explained in terms of transport processes related to geographical, hydrological and biological factors. In this respect, it has been recognised that drainage waters from the northern opencast-worked polymetallic sulphide deposits constitute a chronic input of heavy metals into the park. Waste waters from olive-oil manufacturing mills in the area may also contribute to the mobilisation of metals towards the park. However, the resulting relative distributions of Zn, Cu and Pb within the park differ from those of mine effluents, indicating a differential transport of these metals through the water systems. Zinc seems to be the best indicator of input from the mining area. Petroleum hydrocarbons enter the park from the SE via the main rivers and tidal sea movements, whereas PAHs, PCBs and DDTs are uniformly distributed at very low levels in surface sediments, indicating a contribution by aeolian transport. Evidence of inefficient recycling of organic matter in the shallow ponds is obtained by the identification of well preserved natural products from local plants and chemical markers of denitrifying bacteria (cyanobacterial markers).

Oil spills in Narragansett Bay: Comparison between federal and state records

Oil spill response in the US is divided among several jurisdictions due to separate and overlapping legislative and regulatory authority. In Rhode Island, data concerning oil spill incidents are kept by two agencies of the federal government and by one agency of the state government. Narragansett Bay and its tributaries are geographically in three jurisdictions; however, because of a tradition of good interagency cooperation, there were very few duplications in spill response. Because each agency has differing expertise and equipment, the types of spill incidents reported by each, if considered separately, present an entirely different picture of the nature of oil spills in this region. Assessment of oil spills as a source of pollution to coastal waters requires examination of all data, not only that from one agency. For Narragansett Bay and its tributaries, oil spills were a minor part of the total oil pollution budget.

Annual Input of Petroleum Hydrocarbons to the Coastal Environment via Urban Runoff

To compile an oil pollution budget for Narragansett Bay, Rhode Island, urban runoff samples were collected at four storm drains each serving a different land use. Three to six storm events with different rainfall amounts were monitored at each drain, and the samples were analyzed for petroleum hydrocarbons using glass capillary gas chromatography. The hydrocarbon (HC) load for each storm (mass HC/area) varied systematically with total rainfall, and the storm event load–rainfall relationship was different for each land use. Using rainfall records, the load for each storm was calculated and then summed to predict an annual input rate of hydrocarbons to receiving waters in terms of mass HC/area for each land use. Industrial and interstate highway land gave the highest loads followed by commercial and residential land, respectively. Finally, an estimate of the total hydrocarbon annual input to Narragansett Bay via urban runoff was compiled using land use data from cities and towns in the drainage basin.

Pollution budgeting: A concept whose times has come

The paper provides a discussion of the pollution budgeting concept and the use of emissions trading as an implementation strategy. The paper is divided into three sections. Section 1 discusses the use of emissions trading to implement the pollution budget concept. Section 2 provides a discussion of the policy problems that have arisen in the implementation of emissions trading as a transitional system. Section 3 provides concluding comments.

Emissions trading: An improved technique for air quality management

The emissions trading program was one of the first major regulatory reform efforts at the U.S. Environmental Protection Agency under the Reagan Administration. This program is a set of guidelines for the states to develop federally approved transactions in discharge permits, called an Emission Reduction Credit. The rules governing emissions trading apply within a total ambient constraint or “pollution budget.” This paper provides a discussion of the emissions trading program as an improved technique for air quality management. The paper begins with a discussion of the concept of emissions trading and how the EPA emissions trading program fits into the U.S. Clean Air Act. It is then argued that emissions trading provides a more cost-effective set of implementation incentives in comparison to a “command and control” regulatory system. A number of important attributes of the emissions trading program are discussed, and estimates of cost reductions are provided. The current status of the implementation of the emissions trading program is discussed. The paper concludes with a discussion of several legal, technical, and administrative obstacles to obtaining the efficiencies of emissions trading.

The computation of a pollutant budget for the Arctic Ocean

Abstract An equation is proposed for calculating the pollutant budget of the Arctic Ocean, and its application is illustrated on the basis of data for oil pollution.

The equitable approach to pollution control management in the thames estuary

Wood & Cockburn (IAWPR Conference, Vienna, 1979) outlined the theory of an equitable approach to pollution control. In order to use this approach, the pollution budget for the stretch of river must be defined, and this budget must be distributed equitably among the dischargers. The equitable approach assumes that all dischargers have an equal right to a share of the budget proportional to the potential load which would have been discharged were no treatment given. This paper extends the theory into practice and discusses some of the advantages and problems in the Thames Estuary. The dissolved oxygen pollution budget, based on quality objectives for the Thames, is defined, and is distributed equitably amongst the dischargers. In setting the equitable allowances it is clear that other restraints prevent the fresh water rivers from using their full allowance, and this becomes available for other dischargers, further, it is difficult to properly ascribe allowances for non-point discharges and storm discharges. Because the setting of the pollution budget, and the equitable approach use two different bases, they are not necessarily compatible, and therefore in the Thames a purely equitable approach would result in some failure to meet the objectives. A method for overcoming the problem is set out in the paper. When compatibility between equitability and the quality objectives has been achieved, required discharge standards can be calculated.