Fluxes of Gaseous Elemental Mercury at a Mediterranean Coastal Grassland

Coastal rural areas can be a source of elemental mercury, but the potential influence of their topographic and climatic particularities on gaseous elemental mercury (GEM) fluxes have not been investigated extensively. In this study gaseous elemental mercury was measured over Mediterranean coastal grassland located at Northern Greece from 2014 to 2015 and GEM fluxes were evaluated utilizing Monin-Obukhov similarity theory. The GEM fluxes ranged from -50.30 to 109.695 ng m-2 h-1 with a mean value equal to 10.501 ng m-2 h-1 ± 19.14 ng m-2 h-1. Concerning the peak events, with high positive and low negative GEM fluxes, those were recorded from the morning until the evening. Rain events were a strong contributing factor for enhanced GEM fluxes. The enhanced turbulent mixing under daytime unstable conditions led to greater evasion and positive GEM fluxes while during nighttime periods the GEM evasion is lower indicating the effect of atmospheric stability on GEM fluxes. The coastal grassland with its specific characteristics influences the GEM fluxes and this area could be characterized as source of elemental mercury. This study is one of the rare efforts in the research community to estimate GEM fluxes in a coastal natural site based on aerodynamic gradient method.

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Fluxes of Gaseous Elemental Mercury on a Mediterranean Coastal Grassland

Atmosphere ◽

10.3390/atmos10090485 ◽

2019 ◽

Vol 10 (9) ◽

pp. 485

Author(s):

Christiana Polyzou ◽

Glykeria Loupa ◽

Aikaterini Trepekli ◽

Spyridon Rapsomanikis

Keyword(s):

Turbulent Mixing ◽

Rural Areas ◽

Similarity Theory ◽

Atmospheric Stability ◽

Elemental Mercury ◽

Mean Value ◽

Potential Influence ◽

Northern Greece ◽

Gaseous Elemental Mercury ◽

Rain Events

Coastal rural areas can be a source of elemental mercury, but the potential influence of their topographic and climatic particularities on gaseous elemental mercury (GEM) fluxes have not been investigated extensively. In this study, gaseous elemental mercury was measured over Mediterranean coastal grassland located in Northern Greece from 2014 to 2015 and GEM fluxes were evaluated utilizing Monin–Obukhov similarity theory. The GEM fluxes ranged from –50.30 to 109.69 ng m−2 h−1 with a mean value equal to 10.50 ± 19.14 ng m−2 h−1. Concerning the peak events, with high positive and low negative GEM fluxes, those were recorded from the morning until the evening. Rain events were a strong contributing factor for enhanced GEM fluxes. The enhanced turbulent mixing under daytime unstable conditions led to greater evasion and positive GEM fluxes, while, during nighttime periods, the GEM evasion is lower, indicating the effect of atmospheric stability on GEM fluxes. The coastal grassland with its specific characteristics influences the GEM fluxes and this area could be characterized as a source of elemental mercury. This study is one of the rare efforts in the research community to estimate GEM fluxes in a coastal natural site based on aerodynamic gradient method.

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Effect of sources and meteorological conditions on the concentration and distribution of gaseous elemental mercury in the urban atmosphere

10.32920/ryerson.14650035 ◽

2021 ◽

Author(s):

Daniel Prete

Keyword(s):

Rural Areas ◽

Elemental Mercury ◽

Average Concentration ◽

Meteorological Conditions ◽

Urban Atmosphere ◽

Mercury Vapour ◽

Data Set ◽

Gaseous Elemental Mercury ◽

Regional Sources ◽

High Mercury

Atmospheric gaseous elemental mercury (GEM) and meteorological parameters were monitored at two sites in downtown Toronto, Canada from Oct. 2015 to Oct. 2016 using Tekran 2537A mercury vapour analyzers. The average concentration was found to be 1.78 ± 0.89 ng/m3 for Kerr Hall North (KHN) and 1.46 ± 0.54 ng/m3 for Jorgenson Hall (JOR) site. Analysis of the data reveals that sporadic events of high mercury concentration are related to local sources. Comparing this data set with that collected in 2004 revealed that the average atmospheric GEM concentration in downtown Toronto dropped from 4.5 ng/m3 to 1.78 ng/m3. Decreases in GEM were also observed over the same period in rural areas as measured by CAMNet. The decrease might be a result of policy change, as three key national and provincial environmental policies have been enacted since 2004. The data collected in Toronto suggest GEM concentration and distribution are influenced by local and regional sources, meteorological conditions, and changes in environmental policy.

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Effect of sources and meteorological conditions on the concentration and distribution of gaseous elemental mercury in the urban atmosphere

10.32920/ryerson.14650035.v1 ◽

2021 ◽

Author(s):

Daniel Prete

Keyword(s):

Rural Areas ◽

Elemental Mercury ◽

Average Concentration ◽

Meteorological Conditions ◽

Urban Atmosphere ◽

Mercury Vapour ◽

Data Set ◽

Gaseous Elemental Mercury ◽

Regional Sources ◽

High Mercury

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SOME CHARACTERISTICS OF ATMOSPHERIC BOUNDARY LAYER OVER MAKASSAR

Jurnal Ilmu Kelautan SPERMONDE ◽

10.20956/jiks.v4i1.3797 ◽

2018 ◽

Vol 4 (1) ◽

Cited By ~ 1

Author(s):

Alimuddin Hamzah Assegaf ◽

Wasir Samad ◽

Sakka Sakka

Keyword(s):

Boundary Layer ◽

Similarity Theory ◽

Atmospheric Stability ◽

Mean Value ◽

Atmospheric Parameters ◽

Convective Boundary ◽

Obukhov Length ◽

Wind Characteristics ◽

Stability Classification

Some upper air atmospheric parameters measured during period of 2011-2016 by means of radiosonde located at Hasanuddin International Airport were examined for characterization of boundary layer over Makassar, Indonesia. These data, combined with surface atmospheric parameters were used to calculate some boundary layer parameters using AERMET model which based on Monin-Obukhov similarity theory. The obtained Monin-Obukhov length which reflecting atmospheric stability then converted into traditional Pasquill-Gifford stability classification. Examination of wind characteristics of wind showing clearly their dependence of the day, season and height. Winds dominantly flows from the southeast during the daytime with the relatively larger velocity and from the northwest with smaller velocity during the nighttime. Interpretation of monin-obukhov length using Pasquill-Gifford stability classification showing that the atmosphere was dominantly unstable during the daytime and dominantly stable during the nighttime. These atmospheric stabilities were also varied during seasons. The height of convective boundary layer (CBL) was start to rise in the morning and reaching its maximum in the afternoon (18:00) at the mean value of 2 km. Meanwhile, the height of mechanical boundary layer (MBL) during the day time forming parabolic curve with its maximum value of 1.2 km at noon. These indicated that any released pollution from the stack will be less dispersed during the nighttime due to the fact of lower mixing height, lower wind speed, atmosphere become more stable, and it dispersed in different direction compare to the daytime.

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Air Concentrations of Gaseous Elemental Mercury and Vegetation–Air Fluxes within Saltmarshes of the Tagus Estuary, Portugal

Atmosphere ◽

10.3390/atmos12020228 ◽

2021 ◽

Vol 12 (2) ◽

pp. 228

Author(s):

Rute Cesário ◽

Nelson J. O’Driscoll ◽

Sara Justino ◽

Claire E. Wilson ◽

Carlos E. Monteiro ◽

...

Keyword(s):

Leaf Area ◽

Elemental Mercury ◽

Ambient Air ◽

Tagus Estuary ◽

Contaminated Site ◽

Gaseous Elemental Mercury ◽

Mercury Flux ◽

Sarcocornia Fruticosa ◽

Air Concentrations

In situ air concentrations of gaseous elemental mercury (Hg(0)) and vegetation–atmosphere fluxes were quantified in both high (Cala Norte, CN) and low-to-moderate (Alcochete, ALC) Hg-contaminated saltmarsh areas of the Tagus estuary colonized by plant species Halimione portulacoides (Hp) and Sarcocornia fruticosa (Sf). Atmospheric Hg(0) ranged between 1.08–18.15 ng m−3 in CN and 1.18–3.53 ng m−3 in ALC. In CN, most of the high Hg(0) levels occurred during nighttime, while the opposite was observed at ALC, suggesting that photoreduction was not driving the air Hg(0) concentrations at the contaminated site. Vegetation–air Hg(0) fluxes were low in ALC and ranged from −0.76 to 1.52 ng m−2 (leaf area) h−1 for Hp and from −0.40 to 1.28 ng m−2 (leaf area) h−1 for Sf. In CN, higher Hg fluxes were observed for both plants, ranging from −9.90 to 15.45 ng m−2 (leaf area) h−1 for Hp and from −8.93 to 12.58 ng m−2 (leaf area) h−1 for Sf. Mercury flux results at CN were considered less reliable due to large and fast variations in the ambient air concentrations of Hg(0), which may have been influenced by emissions from the nearby chlor-alkali plant, or historical contamination. Improved experimental setup, the influence of high local Hg concentrations and the seasonal activity of the plants must be considered when assessing vegetation–air Hg(0) fluxes in Hg-contaminated areas.

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An Integrated Investigation of Atmospheric Gaseous Elemental Mercury Transport and Dispersion Around a Chlor-Alkali Plant in the Ossola Valley (Italian Central Alps)

Toxics ◽

10.3390/toxics9070172 ◽

2021 ◽

Vol 9 (7) ◽

pp. 172

Author(s):

Laura Fantozzi ◽

Nicoletta Guerrieri ◽

Giovanni Manca ◽

Arianna Orrù ◽

Laura Marziali

Keyword(s):

Elemental Mercury ◽

Background Concentration ◽

Dispersion Pattern ◽

Central Alps ◽

Gaseous Elemental Mercury ◽

Mercury Transport ◽

Close Proximity ◽

Potential Impact ◽

Hg Accumulation

We present the first assessment of atmospheric pollution by mercury (Hg) in an industrialized area located in the Ossola Valley (Italian Central Alps), in close proximity to the Toce River. The study area suffers from a level of Hg contamination due to a Hg cell chlor-alkali plant operating from 1915 to the end of 2017. We measured gaseous elemental Hg (GEM) levels by means of a portable Hg analyzer during car surveys between autumn 2018 and summer 2020. Moreover, we assessed the long-term dispersion pattern of atmospheric Hg by analyzing the total Hg concentration in samples of lichens collected in the Ossola Valley. High values of GEM concentrations (1112 ng m−3) up to three orders of magnitude higher than the typical terrestrial background concentration in the northern hemisphere were measured in the proximity of the chlor-alkali plant. Hg concentrations in lichens ranged from 142 ng g−1 at sampling sites located north of the chlor-alkali plant to 624 ng g−1 in lichens collected south of the chlor-alkali plant. A north-south gradient of Hg accumulation in lichens along the Ossola Valley channel was observed, highlighting that the area located south of the chlor-alkali plant is more exposed to the dispersion of Hg emitted into the atmosphere from the industrial site. Long-term studies on Hg emission and dispersion in the Ossola Valley are needed to better assess potential impact on ecosystems and human health.

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Oxidation efficiency and reaction mechanisms of gaseous elemental mercury by using CeO2/TiO2 and CuO/TiO2 photo-oxidation catalysts at low temperatures in multi-pollutant environments

Journal of the Taiwan Institute of Chemical Engineers ◽

10.1016/j.jtice.2021.06.033 ◽

2021 ◽

Author(s):

Jun-Zhu Yang ◽

Iau-Ren Ie ◽

Zu-Bei Lin ◽

Chung-Shin Yuan ◽

Huazhen Shen ◽

...

Keyword(s):

Reaction Mechanisms ◽

Low Temperatures ◽

Elemental Mercury ◽

Oxidation Catalysts ◽

Gaseous Elemental Mercury ◽

Photo Oxidation ◽

Oxidation Efficiency

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Occurrence of Volcanogenic Inorganic Mercury in Wild Mice Spinal Cord: Potential Health Implications

Biological Trace Element Research ◽

10.1007/s12011-021-02890-0 ◽

2021 ◽

Author(s):

A. Navarro-Sempere ◽

M. García ◽

A. S. Rodrigues ◽

P. V. Garcia ◽

R. Camarinho ◽

...

Keyword(s):

Spinal Cord ◽

Inorganic Mercury ◽

Elemental Mercury ◽

Potential Health ◽

Wild Mice ◽

Gaseous Elemental Mercury ◽

Lumbar Level ◽

Quantification Analysis ◽

Spinal Cord Potential ◽

Cord Potential

AbstractMercury accumulation has been proposed as a toxic factor that causes neurodegenerative diseases. However, the hazardous health effects of gaseous elemental mercury exposure on the spinal cord in volcanic areas have not been reported previously in the literature. To evaluate the presence of volcanogenic inorganic mercury in the spinal cord, a study was carried out in São Miguel island (Azores, Portugal) by comparing the spinal cord of mice exposed chronically to an active volcanic environment (Furnas village) with individuals not exposed (Rabo de Peixe village), through the autometallographic silver enhancement histochemical method. Moreover, a morphometric and quantification analysis of the axons was carried out. Results exhibited mercury deposits at the lumbar level of the spinal cord in the specimens captured at the site with volcanic activity (Furnas village). A decrease in axon calibre and axonal atrophy was also observed in these specimens. Given that these are relevant hallmarks in the neurodegenerative pathologies, our results highlight the importance of the surveillance of the health of populations chronically exposed to active volcanic environments.

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A Study of the Effects of Rain, Snow and Hail on the Atmospheric Electric Field near Ground

Atmosphere ◽

10.3390/atmos12080996 ◽

2021 ◽

Vol 12 (8) ◽

pp. 996

Author(s):

Athanasios Karagioras ◽

Konstantinos Kourtidis

Keyword(s):

Frequency Distribution ◽

Complex Structure ◽

Potential Gradient ◽

Weather Conditions ◽

The Other ◽

Fair Weather ◽

Northern Greece ◽

Rain Events ◽

The Impact ◽

Bounce Back

The purpose of the present study is to investigate the impact of rain, snow and hail on potential gradient (PG), as observed in a period of ten years in Xanthi, northern Greece. An anticorrelation between PG and rainfall was observed for rain events that lasted several hours. When the precipitation rate was up to 2 mm/h, the decrease in PG was between 200 and 1300 V/m, in most cases being around 500 V/m. An event with rainfall rates up to 11 mm/h produced the largest drop in PG, of 2 kV/m. Shortly after rain, PG appeared to bounce back to somewhat higher values than the ones of fair-weather conditions. A decrease in mean hourly PG was observed, which was around 2–4 kV/m during the hail events which occurred concurrently with rain and from 0 to 3.5 kV/m for hail events with no rain. In the case of no drop, no concurrent drop in temperature was observed, while, for the other cases, it appeared that, for each degree drop in temperature, the drop in hourly mean PG was 1000 V/m; hence, we assume that the intensity of the hail event regulates the drop in PG. The frequency distribution of 1-minute PG exhibits a complex structure during hail events and extend from −18 to 11 kV/m, with most of the values in the negative range. During snow events, 1-minute PG exhibited rapid fluctuations between high positive and high negative values, its frequency distribution extending from −10 to 18 kV/m, with peaks at −10 and 3 kV/m.

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