Suchergebnisse

AbstractMercury is a toxic pollutant that exists in the atmosphere in several forms, operationally identified according to their chemical and physical characteristics. The problem of atmospheric mercury pollution has recently received increasing attention, as evidenced by the numerous European regulations issued in the last years. The normative question is closely related to the methodological one, as the quantification of the mercury species is strictly linked to the sampling and analysis methods. Due to their different bioavailability, airborne mercury forms detection is fundamental both in outdoor and indoor (i.e., workplace) environments. This paper presents an overview of European legislation on atmospheric mercury pollution, with particular attention to the Italian legislation. Starting from the regulatory protocols, the methodological framework for mercury quantification was reviewed, underlining the limits and the problems of the different methodologies and providing new guidance for the analysis. Regulatory and methodological updates have led to great specificity in mercury quantification, which is distinguished for the outdoor and indoor environments. For workplace environments, all mercury species (i.e., gaseous and particulate mercury) are required to be quantified by the Italian legislation; on the contrary, only gaseous compounds are monitored in outdoor conditions. It hence appears of primary importance that the monitoring operator chooses the sampling and analytical method for mercury sampling and analysis that correctly adheres to the normative regulations. Detailed norms describe how to carry on the monitoring in both outdoor and indoor conditions, preventing the operator's arbitrariness, which otherwise can lead to airborne mercury underestimation/overestimation.

AbstractBiomonitoring studies are often employed to track airborne pollutants both in outdoor and indoor environments. In this study, the mercury (Hg) sorption by three biomonitors, i.e., Pinus nigra bark, Pseudovernia furfuracea lichen, and Hypnum cupressiforme moss, was investigated in controlled (indoor) conditions. In comparison to outdoor environments, controlled conditions offer the opportunity to investigate more in detail the variables (humidity, temperature, pollutants speciation, etc.) that control Hg uptake. The biomonitors were exposed in two distinct periods of the year for 2 and 12 months respectively, in the halls of the Central Italian Herbarium (Natural History Museum of the University of Florence, Italy), which are polluted by Hg, due to past plant sample treatments. The Hg sorption trend was monitored every 3 weeks by recording: (i) the Hg content in the substrata, (ii) gaseous elemental mercury (GEM) concentrations in the exposition halls, (iii) temperature, (iv) humidity, and (v) particulate matter (PM) concentrations. At the end of the experiment, Hg concentrations in the biomonitors range from 1130 ± 201 to 293 ± 45 μg kg−1 (max–min) in barks, from 3470 ± 571 to 648 ± 40 μg kg−1 in lichens, and from 3052 ± 483 to 750 ± 127 μg kg−1 in mosses. All the biomonitors showed the highest Hg accumulation after the first 3 weeks of exposure. Mercury concentrations increased over time showing a continuous accumulation during the experiments. The biomonitors demonstrated different Hg accumulation trends in response to GEM concentrations and to the different climatic conditions (temperature and humidity) of the Herbarium halls. Barks strictly reflected the gaseous Hg pollution, while lichen and moss accumulation was also influenced by the climatic conditions of the indoor environment. Mercury bound to PM seemed to provide a negligible contribution to the biomonitors final uptake.