Anthropogenic mercury emission in Europe

Preliminary estimates of Hg emissions from anthropogenic sources in Europe have been prepared to meet the request of air pollution transport modeling. Major emphasis was placed on four source categories: 1) combustion of fossil fuels, 2) non-ferrous metal production, 3) waste related sources, and 4) chlor-alkali production. Three chemical species: elemental, bivalent and particulate Hg were considered in these estimates. The emission estimates were spatially distributed within the EMEP grid of 150 km × 150 km for the year 1982.     

Global Emission of Mercury from Anthropogenic Sources in 1995

An estimate of the global emission of mercury from anthropogenicsources in 1995 has been prepared. Major emphasis is placed onemissions from stationary combustion sources, non-ferrous metalproduction, pig iron and steel production, cement production andwaste disposal. About three quarters of the total emission,estimated to be about 1900 tonnes, was from combustion of fuels, particularly coal combustion in China, India, and South and NorthKorea. In general, the Asian countries contribute about 56% to the global emissions of mercury to the atmosphere. Europe and North America seem to contribute less than 25%. The major chemical form of mercury emitted to the atmosphere is gaseouselemental mercury, contributing with about 53% to the totalemissions, followed by gaseous bivalent mercury with 37%. The Hg emissions on particles contribute only about 10% to the total emissions. Again, Asia contributes about 50% to the totalemissions of all individual chemical forms of mercury.     

Radiographic changes associated with tooth resorption type 2 in cats

The aim of this retrospective study was to follow the progression of radiographic changes in intentionally retained roots of teeth affected with tooth resorption type 2 in cats. Emphasis was placed on assessment of degree of resorption as well as the occurrence of inflammatory changes in tooth roots. The results confirm that crown amputation is an adequate treatment in cats for teeth affected by type 2 resorption.     

A Module to Calculate Primary Particulate Matter Emissions and Abatement Measures in Europe

Primary particulate matter is emitted directly into the atmosphere from various anthropogenic and natural sources such as power plants (combustion of fossil fuels) or forest fires. Secondary particles are formed by transformation of SO₂, NO_x, NH₃, and VOC in the atmosphere. They both contribute to ambient particulate matter concentrations, which may have adverse effects on human health. Health hazards are caused by small particulate size, high number of especially fine (< 2.5 µm) and ultra-fine (< 0.1 µm) particles and/or their chemical composition. As part of an integrated assessment model developed at IIASA, a module on primary particulate matter (PM) emissions has been added to the existing SO₂, NO_x, NH₃ and VOC sections. The module considers so far primary emissions of total suspended particles (TSP), PM₁₀ and PM_2.5 from aggregated stationary and mobile sources. A primary PM emission database has been established. Country specific emission factors for stationary sources have been calculated within the module using the ash content of solid fuels.     

Behaviour of sulphur and nitrogen compounds measured at marine stations Lista and Säby in Scandinavia

Long distance transport of various air pollutants has been studied at two Scandinavian coastal sites. The measuring period has covered one year divided into 4 campaigns. Seasonal variations for sulphur and nitrogen compounds as well as anthropogenically emitted metals are reported. Concentrations of Pb and Zn as well as the ratio of V/Ni concentrations have been used to trace sulphuric episodes. Covariation of anthropogenic pollutants for the two sites is demonstrated.     

Long-term changes in concentration and deposition of atmospheric mercury over Scandinavia

Samples for measurements of total gaseous mercury (Hg) in air have been collected since 1980 in south-western part of Scandinavia. A collection program for precipitation samples used to determine changes in depositional fluxes of total Hg has been in operation since 1987. A comparison of today's total gaseous Hg levels in air and the total Hg concentrations in precipitation with the ones found earlier, shows a clear decrease with time. At the Swedish west-coast, yearly average air concentrations and median levels of 3.3 and 3.1 (1980–1984), 3.2 and 2.8 (1985–1989), and 2.7 and 2.6 ng Hg/m³ (1990–1992), respectively, were found. Increased average and median winter concentrations were always found, with levels at 3.7 and 3.4, 3.7 and 3.3, and 3.0 and 2.7 ng Hg/m³ for the respective time period. Higher winter values were expected due to increased anthropogenic emissions and changes in the mixing height of the atmosphere. The corresponding total wet deposition rates decreased from 27 (1987–1989) to 10 μg Hg/m² yr. (1990–1992). A finding of special interest was the decreased number of episodic events of high total gaseous Hg levels in air, from 1990 and further on. In addition, the frequency distribution of the concentrations of Hg in air seems to be different for these years compared to the other two time periods. A frequency distribution of air concentrations of Hg more resembling a normal distribution was found for the years 1990 to 1992. The decrease of the atmospheric burden of total gaseous Hg and deposition of total Hg are most probably connected to lower emissions in source areas on the European continent. It seems logical to state that the problem of high Hg depositional fluxes to Scandinavia, is best solved by abatement strategies on the regional scale.     

Substance Flow Analysis of Mercury Affecting Water Quality in the European Union

Knowledge concerning the main flows of priority substances (PSs) and the production systems and consumption structures in the society causing these flows is a prerequisite for any attempt to predict and understand their environmental fate as well as to efficiently minimize future environmental burdens. In this paper, a simple SFA diagram on mercury, including the main European Union (EU-27) source categories, flows and environmental endpoints which in turn affect the mercury concentrations in the EU-27 waters are illustrated. From trend analysis and future projections, it becomes obvious that emissions of mercury as a trace contaminant in fuels and minerals (primary anthropogenic emission sources) are becoming increasingly important to the environmental concentrations compared to emissions from mercury used intentionally (secondary anthropogenic sources). Additional future control strategies should therefore be targeted industrial sources and safe treatment of mercury-containing wastes, wastewater effluents, as well as residues collected from various combustion processes. It was found that knowledge on flows and emission sources on a large geographical scale is limited due to a lack of information on emission factors from various industrial processes and waste systems, especially for the mercury being discharges to water and land.     

Mercury Emission from Anthropogenic Sources in Poland and Their Scenarios to the Year 2020

We present the concentrations and distribution patterns of nine acid leachable trace metals (ALTMs) Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, and Cd in the soil samples from the five century old Pachuca-Mineral de Monte mining district of the Central Mexico. The ALTMs do not show any significant correlation with pH, EC, CaCO₃, and organic carbon. The metal concentration indicates three distinct distribution patterns. Fe, Mn, Cr, Pb, and Zn show enrichment in the high altitude region of the northern and central part of the study area. Likewise, Cu and Cd are enriched in the northern mountainous terrains. Both these groups show strong positive correlation with Mn indicating that they are associated with Mn-bearing minerals. However, we relate the first group of metals to excessive vehicular transportation and second group to mining waste dumps. The third group of ALTMs Co and Ni indicates its direct relationship to ore processing activities. Comparison of ALTMs concentrations from this study and various other studies throughout the world suggests the need to take precautionary measures of surface soil in high altitude areas to avoid metal enrichments and its subsequent environmental problems.     

Source-receptor relationships for trace elements in Northern Europe

Measured air concentrations of several trace elements in southern Scandinavia have been related to long range transport and emissions of the same elements from sources in Europe using receptor modelling and statistical trajectory sector analysis. A good agreement, within a factor of 1.5 between estimates and measurements, has been obtained for Mn, Ni, Cu, and As. Significant differences were noted for V and Pb.     

Low levels of ferredoxin, ATP and leghemoglobin contribute to limited N2 fixation of peas (Pisum sativum L.) and alfalfa (Medicago sativa L.) under S deficiency conditions

Sulphur (S) has become a major limiting factor for plant production in industrial as well as in remote industrial rural areas. Limitation of S can reduce legume N₂ fixation by affecting nodule development and function. In pot experiments with pea (Pisum sativum L.) and alfalfa (Medicago sativa L.), we investigated the influence of S on growth, ferredoxin, ATP and leghemoglobin concentrations. Addition of 200 mg S pot⁻¹ increased yield of shoots, roots and nodules of both plant species significantly. However, the influence of S on nodule yield formation was most pronounced. Pea and alfalfa roots were found to have higher S concentrations than shoots and being up to 2.9 times the S concentration in the shoots of peas under S-sufficient conditions. Sulphur addition also increased N₂ fixation significantly. The ferredoxin concentration in bacteroids of root nodules of pea was increased significantly by S only 10 weeks after planting and in bacteroids of root nodules of alfalfa 10 and 17 weeks after planting, while on per pot base the amounts of ferredoxin were higher throughout the experimental period of time. The ATP concentration of bacteroids of root nodules of both plant species as well as of mitochondria of root nodules of pea were significantly higher with optimum S supply. The effects of S deficiency on N₂ fixation are likely to be caused by the shortage of ferredoxin and ATP. The amount of leghemoglobin was reduced in comparison to nodules of the S-sufficient plants.