Mercury in European topsoils: Anthropogenic sources, stocks and fluxes

Abstract

Mercury (Hg) is one of the most dangerous pollutants worldwide. In the European Union (EU), we recently estimated the Hg distribution in topsoil using 21,591 samples and a series of geo-physical inputs. In this manuscript, we investigate the impact of mining activities, chrol-alkali industries and other diffuse pollution sources as primary anthropogenic sources of Hg hotspots in the EU. Based on Hg measured soil samples, we modelled the Hg pool in EU topsoils, which totals about 44.8 Gg, with an average density of 103 g ha −1 . As a following step, we coupled the estimated Hg stocks in topsoil with the pan-European assessment of soil loss due to water erosion and sediment distribution. In the European Union and UK, we estimated that about 43 Mg Hg yr −1 are displaced by water erosion and c. a. 6 Mg Hg yr −1 are transferred with sediments to river basins and eventually released to coastal Oceans. The Mediterranean Sea receives almost half (2.94 Mg yr −1 ) of the Hg fluxes to coastal oceans and it records the highest quantity of Hg sediments. This is the result of elevated soil Hg concentration and high erosion rates in the catchments draining into the Mediterranean Sea. This work contributes to new knowledge in support of the policy development in the on the Zero Pollution Action Plan and the Sustainable Development Goal (SDGs) 3.9 and 14.1, which both have as an objective to reduce soil pollution by 2030.

Assessing the spatial and temporal variability of methylmercury biogeochemistry and bioaccumulation in the Mediterranean Sea with a coupled 3D model

“…Despite the relatively high mean concentrations (Table S6) assumed, the estimated Hg T load is slightly lower than the estimate (6 Mg yr −1 ) from Cossa et al (2022), most likely because the water discharge used in that work (> 350 km 3 yr −1 ) is higher than the total discharge used in this model setup (> 291 km 3 yr −1 ). On the other hand, the load to the Mediterranean Sea from solely European rivers (2.9 Mg yr −1 ) estimated from Hg concentrations in topsoils and water erosion rates from river catchments (Panagos et al, 2021) is slightly lower than the load from European rivers in our model setup (3.25 Mg yr −1 ). Finally, all these estimates are lower than the 18 Mg yr −1 computed by Liu et al ( 2021) for the Mediterranean Sea through a global river model explicitly considering water discharge, suspended solids, and Hg loadings.…”

“…Further, at the mouth of the Soča/Isonzo River, impacted by upstream Hg mining, concentrations of unfiltered Hg higher than 200 pM have been reported (Hines et al, 2000). Hg loads for the Mediterranean tributary were estimated based on this information as synthesized in Table S6, also qualitatively referring to the spatial distribution of Hg stock and erosion fluxes in European topsoils (Panagos et al, 2021) and other information on anthropogenic activities (Ahmed et al, 2018). In the reference simulation, including only the dissolved input, the loading estimate is 0.28 Mg yr −1 for total dissolved Hg (and 0.008 Mg yr −1 for dissolved MMHg), while in the simulation with total Hg inputs the loading is about 4.6 Mg yr −1 , including 0.27 Mg yr −1 of MMHg.…”

Mediterranean Mercury Assessment 2022: An Updated Budget, Health Consequences, and Research Perspectives

“…Riverine and Submarine Groundwater Discharge. According to a recent paper, 120 riverine discharge from European rivers into the MED is 2.9 Mg y −1 ; this input is highly seasonal due to the Mediterranean hydrological regime. 75 However, the inputs from rivers into the Eastern and Southern parts of the MED shore are not included in this inventory.…”

The Renaissance of Wild Food Plants: Insights from Tuscany (Italy)

“…A regional analysis of Tuscan vineyards showed, for example, a rather high mean copper concentration (64.81 mg kg −1 ) [113], probably due to the large use of copper-based products in agriculture [114]. High mercury content has been found in some areas of Tuscany [115], due to pollution coming from geothermal systems and from mining activity. In the area of Monte Amiata, for example, is located the third-highest mercury deposit of Europe [116].…”