Studies of mercury species in the atomosphere in downtown Toronto

2021 ◽  
Author(s):  
Xinjie Song
Keyword(s):  
Meteorological Parameters ◽  
Inorganic Mercury ◽  
Elemental Mercury ◽  
Ambient Air ◽  
Temporal Variations ◽  
Anthropogenic Sources ◽  
Mercury Species ◽  
Gaseous Elemental Mercury ◽  
Reactive Gaseous Mercury ◽  
Mean Concentration

This study had been carried out in downtown Toronto from December 2003 to November 2004. Gaseous elemental mercury (GEM), reactive gaseous mercury (RGM, also called gaseous oxidized inorganic mercury, GOIM) and mercury associated with particles having size (PM<2.5) were simultaneously measured using Tekran mercury speciation unit. Mean concentration, standard deviation and distribution of GEM, PM<2.5 and RGM were 4.52 +/- 3.13 ng m⁻³ (98.7%), 21.51 +/- 16.35 pg m⁻³ (0.5%) and 14.19 +/- 13.24 pg m⁻³ (0.3%), respectively. Local and regional anthropogenic sources are believed to contribute [to] the elevated value and high temporal variations. Overall, the mercury species concentrations are lower in winter than in the other three seasons. Nighttime GEM, PM<2.5 and RGM concentrations are higher than those of daytime. Correlation analysis was conducted between each mercury species and the meteorological parameters (i.e., surface ambient air temperature, relative humidity, wind direction), as well as among the mercury species in this study.

Studies of mercury species in the atomosphere in downtown Toronto

2021 ◽  
Author(s):  
Xinjie Song
Keyword(s):  
Meteorological Parameters ◽  
Inorganic Mercury ◽  
Elemental Mercury ◽  
Ambient Air ◽  
Temporal Variations ◽  
Anthropogenic Sources ◽  
Mercury Species ◽  
Gaseous Elemental Mercury ◽  
Reactive Gaseous Mercury ◽  
Mean Concentration

This study had been carried out in downtown Toronto from December 2003 to November 2004. Gaseous elemental mercury (GEM), reactive gaseous mercury (RGM, also called gaseous oxidized inorganic mercury, GOIM) and mercury associated with particles having size (PM<2.5) were simultaneously measured using Tekran mercury speciation unit. Mean concentration, standard deviation and distribution of GEM, PM<2.5 and RGM were 4.52 +/- 3.13 ng m⁻³ (98.7%), 21.51 +/- 16.35 pg m⁻³ (0.5%) and 14.19 +/- 13.24 pg m⁻³ (0.3%), respectively. Local and regional anthropogenic sources are believed to contribute [to] the elevated value and high temporal variations. Overall, the mercury species concentrations are lower in winter than in the other three seasons. Nighttime GEM, PM<2.5 and RGM concentrations are higher than those of daytime. Correlation analysis was conducted between each mercury species and the meteorological parameters (i.e., surface ambient air temperature, relative humidity, wind direction), as well as among the mercury species in this study.

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

Atmosphere ◽  
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.

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

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.

scholarly journals Simulation of atmospheric mercury depletion events (AMDEs) during polar springtime using the MECCA box model

2008 ◽  
Vol 8 (23) ◽  
pp. 7165-7180 ◽  
Author(s):  
Z.-Q. Xie ◽  
R. Sander ◽  
U. Pöschl ◽  
F. Slemr
Keyword(s):  
Aqueous Phase ◽  
Ozone Depletion ◽  
Elemental Mercury ◽  
Atmospheric Mercury ◽  
Box Model ◽  
Rate Coefficients ◽  
Mercury Species ◽  
Phase Reaction ◽  
Gaseous Elemental Mercury ◽  
Sea Salt Aerosol

Abstract. Atmospheric mercury depletion events (AMDEs) during polar springtime are closely correlated with bromine-catalyzed tropospheric ozone depletion events (ODEs). To study gas- and aqueous-phase reaction kinetics and speciation of mercury during AMDEs, we have included mercury chemistry into the box model MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere), which enables dynamic simulation of bromine activation and ODEs. We found that the reaction of Hg with Br atoms dominates the loss of gaseous elemental mercury (GEM). To explain the experimentally observed synchronous depletion of GEM and O3, the reaction rate of Hg+BrO has to be much lower than that of Hg+Br. The synchronicity is best reproduced with rate coefficients at the lower limit of the literature values for both reactions, i.e. kHg+Br≈3×10−13 and kHg+BrO≤1×10−15 cm3 molecule−1 s−1, respectively. Throughout the simulated AMDEs, BrHgOBr was the most abundant reactive mercury species, both in the gas phase and in the aqueous phase. The aqueous-phase concentrations of BrHgOBr, HgBr2, and HgCl2 were several orders of magnitude larger than that of Hg(SO3)22−. Considering chlorine chemistry outside depletion events (i.e. without bromine activation), the concentration of total divalent mercury in sea-salt aerosol particles (mostly HgCl42−) was much higher than in dilute aqueous droplets (mostly Hg(SO3)22−), and did not exhibit a diurnal cycle (no correlation with HO2 radicals).

scholarly journals A cavity ring-down spectroscopy sensor for measurements of gaseous elemental mercury – Part 1: Development for high time resolution measurements in ambient air

2012 ◽  
Vol 5 (6) ◽  
pp. 8995-9020
Author(s):  
A. Pierce ◽  
D. Obrist ◽  
H. Moosmüller ◽  
X. Faïn ◽  
C. Moore
Keyword(s):  
Time Resolution ◽  
Frequency Conversion ◽  
Elemental Mercury ◽  
Ambient Air ◽  
High Time ◽  
High Time Resolution ◽  
Concentration Data ◽  
Cavity Ring Down Spectroscopy ◽  
Gaseous Elemental Mercury ◽  
Cavity Ring Down

Abstract. The ability to make high time resolution measurements of gaseous elemental mercury (GEM) concentrations in air is imperative for the understanding of mercury cycling. Here we describe further development and field implementation of a laboratory prototype pulsed cavity ring-down spectroscopy (CRDS) system for high time resolution, continuous and automated measurement of GEM concentrations in ambient air. In particular, we present use of an external, isotopically enriched Hg cell for automated wavelength locking and wavelength stabilization to maintain laser wavelength on the peak of GEM absorption line in ambient air. We further describe implementation of differential absorption measurements using a piezoelectric tuning element that allows for continuous accounting of system baseline extinction losses needed to calculate GEM absorption coefficients. Data acquisition systems and software programs were modified to acquire high-speed ring-down data at 50 Hz repetition rate as well as process and analyze data in real time. The system was installed in a mobile trailer, and inlet systems and temperature controls were designed to minimize effects of changes in ambient air temperature and ozone (O3) concentration. Data that identify technical challenges and interferences that occurred during measurements, including temperature fluctuations, interferences by ambient O3 and drifts in frequency conversion efficiencies are discussed. Successful development of a CRDS system capable of measuring ambient air GEM concentrations with high time resolution is based on minimizing these interferences.

scholarly journals Evaluation of cation exchange membrane performance under exposure to high Hg<sup>0</sup> and HgBr<sub>2</sub> concentrations

2019 ◽  
Vol 12 (2) ◽  
pp. 1207-1217 ◽  
Author(s):  
Matthieu B. Miller ◽  
Sarrah M. Dunham-Cheatham ◽  
Mae Sexauer Gustin ◽  
Grant C. Edwards
Keyword(s):  
Cation Exchange ◽  
High Efficiency ◽  
Absolute Humidity ◽  
Elemental Mercury ◽  
Mercury Vapor ◽  
Ambient Air ◽  
Atmospheric Mercury ◽  
Promising Alternative ◽  
Gaseous Elemental Mercury ◽  
High Concentrations

Abstract. Reactive mercury (RM), the sum of both gaseous oxidized Hg and particulate bound Hg, is an important component of the global atmospheric mercury cycle, but measurement currently depends on uncalibrated operationally defined methods with large uncertainty and demonstrated interferences and artifacts. Cation exchange membranes (CEMs) provide a promising alternative methodology for quantification of RM, but method validation and improvements are ongoing. For the CEM material to be reliable, uptake of gaseous elemental mercury (GEM) must be negligible under all conditions and RM compounds must be captured and retained with high efficiency. In this study, the performance of CEM material under exposure to high concentrations of GEM (1.43×106 to 1.85×106 pg m−3) and reactive gaseous mercury bromide (HgBr2 ∼5000 pg m−3) was explored using a custom-built mercury vapor permeation system. Quantification of total permeated Hg was measured via pyrolysis at 600 ∘C and detection using a Tekran® 2537A. Permeation tests were conducted over 24 to 72 h in clean laboratory air, with absolute humidity levels ranging from 0.1 to 10 g m−3 water vapor. GEM uptake by the CEM material averaged no more than 0.004 % of total exposure for all test conditions, which equates to a non-detectable GEM artifact for typical ambient air sample concentrations. Recovery of HgBr2 on CEM filters was on average 127 % compared to calculated total permeated HgBr2 based on the downstream Tekran® 2537A data. The low HgBr2 breakthrough on the downstream CEMs (< 1 %) suggests that the elevated recoveries are more likely related to suboptimal pyrolyzer conditions or inefficient collection on the Tekran® 2537A gold traps.

Measurements of atmospheric gaseous elemental mercury (GEM) and GEM fluxes in the seas of Southeast Asia in October-December 2019

2020 ◽  
Author(s):  
Viktor Kalinchuk ◽  
Evgeny Lopatnikov ◽  
Anatoly Astakhov ◽  
Maksim Ivanov ◽  
Renat Shakirov ◽  
...  
Keyword(s):  
South China Sea ◽  
Sea Of Japan ◽  
South China ◽  
Elemental Mercury ◽  
Ambient Air ◽  
The South China Sea ◽  
The Sea Of Japan ◽  
The South ◽  
Gaseous Elemental Mercury ◽  
China Sea

&lt;p&gt;Measurements of gaseous elemental mercury (GEM) in the marine boundary layer (MBL) and GEM evasion fluxes were carried out during the Russian-Vietnam cruise conducted from the Sea of Japan to the South China Sea from October 25 to December 7, 2019. All GEM measurements were performed using two RA-915M mercury analysers (Lumex LLC, Russia). Atmospheric GEM concentrations were measured at two levels (about 2 m and 20 m above the sea surface) with a time resolution of 30 minutes. GEM fluxes were measured in the South China Sea using a dynamic flux chamber.&lt;/p&gt;&lt;p&gt;GEM concentrations ranged between 0.56 ng/m&lt;sup&gt;3&lt;/sup&gt; and 25.47 ng/m&lt;sup&gt;3&lt;/sup&gt;, and between 0.39 ng/m&lt;sup&gt;3&lt;/sup&gt; and 23.95 ng/m&lt;sup&gt;3&lt;/sup&gt; with medians of 1.38 ng/m&lt;sup&gt;3&lt;/sup&gt; and 1.45 ng/m&lt;sup&gt;3&lt;/sup&gt; for 2 m and 20 m measurements, respectively. GEM concentrations were significantly affected by air transport of GEM. Concentration Weighted Trajectory (CWT) analysis showed several source regions potentially influencing GEM concentrations in the ambient air during the cruise: the south of the South China Sea, Vietnam, the southeastern China, the south of Japan and the Korean peninsula. Maximum concentrations (up to 25 ng/m&lt;sup&gt;3&lt;/sup&gt;) were registered in Haiphong (Vietnam).&lt;/p&gt;&lt;p&gt;Hg(0) fluxes measured at 7 stations in the South China Sea ranged from 1.1 ng/m&lt;sup&gt;2&lt;/sup&gt;/h to 2.5 ng/m&lt;sup&gt;2&lt;/sup&gt;/h, with median value of 2.07 ng/m&lt;sup&gt;2&lt;/sup&gt;/h. These values were 1,5 times higher than those that were measured by the same method in the Sea of Japan and the Sea of Okhotsk a month earlier.&lt;/p&gt;&lt;p&gt;This work was supported by the Russian Science Foundation (RSF) (Project &amp;#8470; 19-77-10011).&lt;/p&gt;

scholarly journals Seasonal and Temporal Variations of Criteria Air Pollutants and the Influence of Meteorological Parameters on the Concentration of Pollutants in Ambient Air in Lahore, Pakistan

2016 ◽  
Vol 59 (1) ◽  
pp. 34-42
Author(s):  
Amtul Bari Tabinda ◽  
Saleha Munir ◽  
Abdullah Yasar ◽  
Asad Ilyas
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Negative Correlation ◽  
Air Pollutants ◽  
Meteorological Parameters ◽  
Ambient Air ◽  
Temporal Variations ◽  
Criteria Air Pollutants ◽  
Summer Minimum ◽  
One Year

Criteria air pollutants have their significance for causing health threats and damage to theenvironment. The study was conducted to assess the seasonal and temporal variations of criteria air pollutantsand evaluating the correlations of criteria air pollutants with meteorological parameters in the city ofLahore, Pakistan for a period of one year from April 2010 to March 2011. The concentrations of criteriaair pollutants were determined at fixed monitoring stations equipped with HORIBA analyzers. The annualaverage concentrations (µg/m3) of PM2.5, O3, SO2, CO and NOx (NO+NO2) for this study period were118.94±57.46, 46.0±24.2, 39.9±8.9, 1940±1300 and 130.9±81.0 (61.8±46.2+57.3±22.19), respectively.PM2.5, SO2, CO and NOx had maximum concentrations during winter whereas O3 had maximum concentrationduring summer. Minimum concentrations of PM2.5, SO2 and NOx were found during monsoon as comparedto other seasons due to rainfall which scavenged these pollutants. The O3 showed positive correlation withtemperature and solar radiation but negative correlation with wind speed. All other criteria air pollutantsshowed negative correlation with wind speed, temperature and solar radiation. A significant (P<0.01)correlation was found between NOx and CO (r = 0.779) which showed that NOx and CO arise from commonsource that could be the vehicular emission. PM2.5 was significantly correlated (P<0.01) with NOx (r = 0.524)and CO (r = 0.519), respectively. High traffic intensity and traffic jams were responsible for increased airpollutants level especially the PM2.5, NOx and CO.

Sign in / Sign up

Export Citation Format

Share Document