Search Results (5)

Mercury, a global pollutant with high biotoxicity, is widely distributed in soils, water bodies, and the atmosphere. Anthropogenic activities such as industrial emissions and coal combustion release large quantities of mercury into the environment, posing health risks to human populations. Strict implementation of the Minamata Convention and innovative remediation technologies can mitigate escalating environmental and public health risks. This study investigated the spatiotemporal dynamics of mercury in soils and atmosphere across four spatial scales (central city, county, township, and village) within the Changchun urban agglomeration, China. During spring, summer, and autumn of 2023, surface soil and atmospheric mercury concentrations (at 0 cm and 100 cm) were measured using LUMEX RA-915+ at 361 sites. Soil mercury exhibited seasonal variability, with a mean concentration of 46.2 µg/kg, showing peak values in spring and troughs in summer; concentrations decreased by 29.40% from spring to summer, followed by a 27.85% rebound in autumn. Spatially, soil mercury concentrations exhibited a core–periphery decreasing gradient (central city > county > township > village). Average concentrations at county, township, and village levels were 9.92%, 35.07%, and 42.11% lower, respectively, than those in the central city. Atmospheric mercury displayed seasonal variations; mean concentrations at 0 cm and 100 cm heights were 6.13 ng/m³ and 6.75 ng/m³, respectively, both peaking in summer. At 0 cm, summer concentrations increased by 35.61% compared to spring, then declined by 35.96% in autumn; at 100 cm, summer concentrations rose by 49.39% from spring and decreased by 31.08% in autumn. Atmospheric mercury at both heights decreased from the central city to the peripheries, with reductions of approximately 40% at 0 cm and 37–39% at 100 cm. Atmospheric mercury dynamics were significantly correlated with meteorological parameters such as temperature and humidity. Spatial autocorrelation analysis revealed scale-dependent clustering patterns: soil mercury Moran’s I ranked central city > county > village > township, while atmospheric mercury followed township > village > county > central city. Structural equation modeling demonstrated that different spatial scales had a significant negative effect on soil mercury concentrations, atmospheric mercury concentrations at 0 cm and 100 cm, and mercury and its compounds emissions. Organic matter content had a significant positive effect on soil mercury content. Temperature and humidity positively influenced near-surface atmospheric mercury. This multi-scale approach elucidates urban agglomeration mercury dynamics, highlighting core–periphery pollution gradients and seasonal patterns, thereby providing empirical evidence for regional mercury transport studies and providing a scientific foundation for future heavy metal management strategies. Full article

Considerable amounts of gaseous elemental mercury (Hg⁰) can be released into the atmosphere from Hg-enriched substrates, such as those from former mining areas, posing a potential environmental threat. In this work, Hg⁰ fluxes at the soil–air interface under natural vegetation covers were measured in various locations within the Idrija Hg mining area (Slovenia) and its surroundings. Sites were selected in order to compare Hg⁰ fluxes from both forest soils heavily impacted by historical ore roasting and urban soils characterised by a different degree of Hg enrichment due to the natural occurrence of Hg in rocks or recent mining and roasting processes. Replicate measurements at each site were conducted using a non-steady state flux chamber coupled with a real-time Hg⁰ analyser (Lumex RA-915M). Moreover, topsoil samples (0–2 cm) were analysed for Hg total concentration and speciation. Cinnabar was the predominant Hg form in almost all the sites. Despite Hg⁰ being undetectable in soils using thermo-desorption, substantial emissions were observed (70.7–701.8 ng m⁻² h⁻¹). Urban soils in a naturally enriched area showed on average the highest Hg⁰ fluxes, whereas relatively low emissions were found at the historical roasting site, which is currently forested, despite the significantly high total Hg content in soils (up to 219.0 and 10,400 mg kg⁻¹, respectively). Overall, our findings confirm that shading by trees or litter may effectively limit the amount of Hg⁰ released into the atmosphere even from extremely enriched soils, thus acting as a natural mitigation. Full article

Atmospheric levels of atomic mercury pollution were measured using spectroscopic techniques in the city of Guangzhou, Guangdong Province, China. Assessments were mainly performed at ground level using a portable (vehicle mounted or hand carried) Zeeman modulation correlation spectrometer (Lumex RA-915M), and the results are given in easily comprehensible diagrams. Measurements were made with continuous recording in car traverses along major roads which cross the city, but also at selected spots, such as at a university campus with laboratory buildings. Further, pollution levels at different locations were recorded when walking through a major and a small hospital. While concentrations in the city in the range 3–10 ng/m³ were typical, and strongly dependent on the traffic situation, very high concentrations (up to 1300 ng/m³) were found at certain indoor hospital locations, again drawing attention to the fact that high mercury levels due to inadequate handling routines can remain undetected but could readily be eliminated by adequate measurements and subsequent sanitation. Full article

Mercury (Hg) is a global pollutant that may potentially have serious impacts on human health and ecologies. The gaseous elemental mercury (GEM) exchanges between terrestrial surfaces and the atmosphere play important roles in the global Hg cycle. This study investigated GEM exchange fluxes over two land cover types (including Artemisia anethifolia coverage and removal and bare soil) using a dynamic flux chamber attached to the Lumex^R RA915+ Hg analyzer during the growing season from May to September of 2018, in which the interactive effects of plant coverage and meteorological conditions were highlighted. The daily mean ambient levels of GEM and the total mercury concentrations of the soil (TSM) were determined to be 12.4 ± 3.6 to 16.4 ± 5.6 ng·m⁻³ and 32.8 to 36.2 ng·g⁻¹, respectively, for all the measurements from May to September. The GEM exchange fluxes (ng·m⁻²·h⁻¹) during the five-month period for the three treatments included the net emissions from the soil to the atmosphere (mean 5.4 to 7.1; range of −27.0 to 47.3), which varied diurnally, with releases occurring during the daytime hours and depositions occurring during the nighttime hours. Significant differences were observed in the fluxes between the vegetation coverage and removal during the growing months (p < 0.05). In addition, it was determined that the Hg fluxes were positively correlated with the solar radiation and air/soil temperature levels and negatively correlated with the air relative humidity and soil moisture under all the conditions (p < 0.05). Overall, the results obtained in this study demonstrated that the grassland soil served as both a source and a sink for atmospheric Hg, depending on the season and meteorological factors. Furthermore, the plants played an important inhibiting role in the Hg exchanges between the soil and the atmosphere. Full article

Mercury is a toxic and noxious element and is the only metal that naturally occurs as gas. One of the most challenging topics (included in the United Nations Minimata convention) is to understand the adsorption–release processes of manmade materials (e.g., concrete, bricks, tiles, painting). Adsorption of Hg by construction and demolition waste materials has recently been studied, but investigations on how much Hg⁰ can be released from these products are rather poor. The abandoned mining site of Abbadia San Salvatore (Siena, central Italy) where, for about one century, cinnabar was roasted to produce liquid mercury, is known for the high concentrations of (i) Hg⁰ in edifices and structures and (ii) total and leachate Hg in synthetic materials. In the present paper, a new, simple and low-cost method to measure the amount of GEM (Gaseous Elemental Mercury) released from anthropic materials (concrete, wall rocks, and tiles) located in the Hg⁰-rich environments of the former mining site, is proposed. The efficiency of a specific paint that was supposed to act as blocking agent to Hg⁰ was also tested. Full article