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Several measures are available for reducing mercury emissions; however, these measures differ with regard to emission control efficiency, cost, and environmental benefits obtained through their implementation. Measures that include the application of technology, such as technology to remove mercury from flue gases in electric power plants, waste incinerators, and smelters, are rather expensive compared with nontechnological measures. In general, dedicated mercury removal is considerably more expensive than a co-benefit strategy, using air pollution control equipment originally designed to limit emissions of criterion pollutants, such as particulate matter, sulfur dioxide, or oxides of nitrogen. Substantial benefits can be achieved globally by introducing mercury emission reduction measures because they reduce human and wildlife exposure to methyl mercury. Although the reduction potential is greatest with the technological measures, technological and nontechnological solutions for mercury emissions and exposure reductions can be carried out in parallel.

Mercury in air has been measured at five coastal Mediterranean sites, involving measurements in Spain, France, Italy, Slovenia and Israel. Four two-weeks long measurements campaigns were performed at the five sites. The measurements were carried out during autumn 2003 and winter, spring and summer 2004. Total gaseous mercury/elemental gaseous mercury, particulate mercury and divalent gaseous mercury were measured in parallel at the five sites. The activities constituted a subtask of the EU funded MERCYMS research project, which also included Mediterranean Sea cruises where both mercury in air and water were measured. The result from an evaluation of all the coastal air data is presented. Mercury concentrations from the different sites are compared with similar data obtained in northern Europe and elsewhere. The result shows that the background concentration of mercury in Mediterranean coastal air is lower than earlier anticipated. Background concentrations of TGM, RGM and TPM corresponded to 1.75–1.80 ng m−3, 1–13 and 3–23 pg m−3, respectively. The measurements also showed that the mercury concentration occasionally can be very high in some areas due to local anthropogenic emissions. It is proposed that diurnal variation in RGM concentrations observed during situation with nocturnal inversion merely is an effect of meteorology rather than due to local photochemistry. [ABSTRACT FROM AUTHOR]

The atmosphere remains the major source of mercury in Swedish ecosystems. Since the late eighties, atmospheric emissions of mercury have drastically decreased in Europe. Wet deposition of mercury has decreased over the last decade but still exhibits a clear south-to-north gradient, greatly influenced by source areas in northern and central Europe. The decreases in emissions can be attributed to both direct measures to close known point sources and a declining economy and energy consumption in many East European countries. Further reductions of mercury emissions will require that other source categories such as indirect emissions from mercury-containing products and crematories are be considered. [ABSTRACT FROM AUTHOR]

Introduces several articles on the scientific aspects related to air pollution in Europe.

Comments on the article 'The European Air Quality Framework Directive and atmospheric mercury: the wrong tool for the job,' by David S. Lee, David Fowler and Eiko Nemitz, which appeared in a 2002 issue of the journal 'Atmospheric Environment.' Proposal of an action plan that incorporates the monitoring of emissions, ambient air concentrations and deposition and the assessment of potential for emission reductions.

Abstract: Five regional scale models with a horizontal domain covering the European continent and its surrounding seas, two hemispheric and one global scale model participated in the atmospheric Hg modelling intercomparison study. The models were compared between each other and with available measurements from 11 monitoring stations of the EMEP measurement network. Because only a very limited number of long-term measurement records of Hg were available, significant attention was given to the intercomparison of modelling results. Monthly and annually averaged values of Hg concentrations and depositions as well as items of the Hg deposition budgets for individual European countries were compared. The models demonstrated good agreement (within ±20%) between annual modelled and observed values of gaseous elemental Hg. Modelled values of Hg wet deposition in Western and Central Europe agreed with the observations within ±45%. The probability to predict wet depositions within a factor of 2 with regard to measurements was 50–70% for all the models. The scattering of modelling results for dry depositions of Hg was more significant (up to ±50% at the annual scale and even higher for monthly data). Contribution of dry deposition to the total Hg deposition was estimated at 20–30% with elevated dry deposition fluxes during summer time. The participating models agree in their predictions of transboundary pollution for individual countries within ±60% at the monthly scale and within ±30% at the annual scale. For the cases investigated, all the models predict that the major part of national anthropogenic Hg emissions is transported outside the country territory. [Copyright &y& Elsevier]

Abstract: As part of the European Mercury Emissions from Chlor Alkali Plants (EMECAP) project, we tested the hypothesis that contamination of ambient air with mercury around chlor alkali plants using mercury cells would increase the internal dose of mercury in people living close to the plants. Mercury in urine (U-Hg) was determined in 225 individuals living near a Swedish or an Italian chlor alkali plant, and in 256 age- and sex-matched individuals from two reference areas. Other factors possibly affecting mercury exposure were examined. Emissions and concentrations of total gaseous mercury (TGM) around the plants were measured and modeled. No increase in U-Hg could be demonstrated in the populations living close to the plants. This was the case also when the comparison was restricted to subjects with no dental amalgam and low fish consumption. The emissions of mercury to air doubled the background level, but contributed only about 2 ng/m3 to long-term averages in the residential areas. The median U-Hg levels in subjects with dental amalgam were 1.2 μg/g creatinine (μg/gC) in Italy and 0.6 μg/gC in Sweden. In individuals without dental amalgam, the medians were 0.9 μg/gC and 0.2 μg/gC, respectively. The number of amalgam fillings, as well as chewing, fish consumption, and female sex were associated with higher U-Hg. The difference between the countries is probably due to higher fish consumption in Italy, demethylated methyl mercury (MeHg) being partly excreted in urine. Post hoc power calculations showed that if the background mercury exposure is low it may be possible to demonstrate an increase in U-Hg of as little as about 10 ng/m3 as a contribution to ambient mercury from a point source. [Copyright &y& Elsevier]

Mercury (Hg) is regarded as a major environmental concern in many regions, traditionally because of high concentrations in freshwater fish, and now also because of potential toxic effects on soil microflora. The predominant source of Hg in most watersheds is atmospheric deposition, which has increased 2- to >20-fold over the past centuries. A promising approach for supporting current European efforts to limit transboundary air pollution is the development of emission-exposure-effect relationships, with the aim of determining the critical level of atmospheric pollution (CLAP, cf. critical load) causing harm or concern in sensitive elements of the environment. This requires a quantification of slow ecosystem dynamics from short-term collections of data. Aiming at an operational tool for assessing the past and future metal contamination of terrestrial and aquatic ecosystems, we present a simple and flexible modelling concept, including ways of minimizing requirements for computation and data collection, focusing on the exposure of biota in forest soils and lakes to Hg. Issues related to the complexity of Hg biogeochemistry are addressed by (1) a model design that allows independent validation of each model unit with readily available data, (2) a process- and scale-independent model formulation based on concentration ratios and transfer factors without requiring loads and mass balance, and (3) an equilibration concept that accounts for relevant dynamics in ecosystems without long-term data collection or advanced calculations. Based on data accumulated in Sweden over the past decades, we present a model to determine the CLAP-Hg from standardized values of region- or site-specific synoptic concentrations in four key matrices of boreal watersheds: precipitation (atmospheric source), large lacustrine fish (aquatic receptor and vector), organic soil layers (terrestrial receptor proxy and temporary reservoir), as well as new and old lake sediments (archives of response dynamics). Key dynamics in watersheds are accounted for by quantifying current states of equilibration in both soils and lakes based on comparison of contamination factors in sediment cores. Future steady-state concentrations in soils and fish in single watersheds or entire regions are then determined by corresponding projection of survey data. A regional-scale application to southern Sweden suggests that the response of environmental Hg levels to changes in atmospheric Hg pollution is delayed by centuries and initially not proportional among receptors (atmosphere≫soils≠sediments>fish; clearwater lakes≫humic lakes). This has implications for the interpretation of common survey data as well as for the implementation of pollution control strategies. Near Hg emission sources, the pollution of organic soils and clearwater lakes deserves attention. Critical receptors, however, even in remote areas, are humic waters, in which biotic Hg levels are naturally high, most likely to increase further, and at high long-term risk of exceeding the current levels of concern: ⩽0.5 mg (kg fw)−1 in freshwater fish, and 0.5 mg (kg dw)−1 in soil organic matter. If environmental Hg concentrations are to be reduced and kept below these critical limits, virtually no man-made atmospheric Hg emissions can be permitted. [Copyright &y& Elsevier]