Annual atmospheric mercury species in Downtown Toronto, Canada

Song, Xinjie; Cheng, Irene; Lu, Junjie

doi:10.1039/b815435j

Cited by 64 publications

(47 citation statements)

References 36 publications

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“…The maximum levels appeared right before sunrise, followed by rapid decreases after sunrise, and daily minimum shortly after noon. Similar diurnal patterns were observed in other urban cities, such as Guiyang, China [27], Detroit, U.S. [28], and Toronto, Canada [29].…”

Section: Seasonal and Diurnal Variationssupporting

confidence: 57%

“…(2) Mercury accumulates overnight under the influence of a low nocturnal boundary layer, and reaches its maximum before sunrise, followed by a rapid decrease after sunrise and a daily minimum in the afternoon. This pattern most commonly occurs in urban sites where strong local and regional emissions are predominant [27][28][29]. (3) Mercury rapidly increases right after sunrise, followed by a gradual decrease in the later hours.…”

Section: Introductionmentioning

confidence: 99%

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Seasonal and Diurnal Variations of Total Gaseous Mercury in Urban Houston, TX, USA

Talbot

Laine³

et al. 2014

Atmosphere

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Total gaseous mercury (THg) observations in urban Houston, over the period from August 2011 to October 2012, were analyzed for their seasonal and diurnal characteristics. Our continuous measurements found that the median level of THg was 172 parts per quadrillion by volume (ppqv), consistent with the current global background level. The seasonal variation showed that the highest median THg mixing ratios occurred in summer and the lowest ones in winter. This seasonal pattern was closely related to the frequency of THg episodes, energy production/consumption and precipitation in the area. The diurnal variations of THg exhibited a pattern where THg accumulated overnight and reached its maximum level right before sunrise, followed by a rapid decrease after sunrise. This pattern was clearly influenced by planetary boundary layer (PBL) height and horizontal winds, including the complex sea breeze system in the Houston area. A predominant feature of THg in the Houston area was the frequent occurrence of large THg spikes. Highly concentrated pollution plumes revealed that mixing ratios of THg were related to not only the combustion tracers CO, CO 2 , and NO, but also CH 4 which is presumably released from oil and natural gas operations, landfills and waste treatment. Many THg episodes occurred simultaneously with peaks in CO, CO 2 , CH 4 , NO x , and/or SO 2 , suggesting possible contributions from similar sources with multi-source types. Our measurements revealed that the mixing ratios and variability of THg were primarily controlled by nearby mercury sources. OPEN ACCESSAtmosphere 2014, 5 400

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Section: Seasonal and Diurnal Variationssupporting

confidence: 57%

Section: Introductionmentioning

confidence: 99%

Seasonal and Diurnal Variations of Total Gaseous Mercury in Urban Houston, TX, USA

Talbot

Laine³

et al. 2014

Atmosphere

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“…Average GOM and PBM concentrations at Dartmouth were lower than many of the urban sites listed in Table 1 even after consideration of the 30-40 % uncertainties for GOM concentrations (Gustin and Jaffe, 2010). Previous studies conducted at urban sites have not only observed higher atmospheric Hg concentrations than those at rural sites, but also larger variability in the concentrations (Gabriel et al, 2005;Song et al, 2009;Liu et al, 2010). The overall variability in GEM concentrations based on relative standard deviation at Dartmouth was comparable to some of the major cities, such as Toronto, Windsor, Detroit, and Birmingham.…”

Section: Overall Concentrationsmentioning

confidence: 91%

“…The higher GOM concentrations in spring at Dartmouth were consistent with some urban sites, including Rochester, New York; Beltsville, Maryland; New Brunswick, New Jersey; The Bronx, New York; and Birmingham, Alabama. However, many of the urban sites also experienced higher GOM concentrations in summer or fall (Rutter et al, 2007;Lyman and Gustin, 2009;Song et al, 2009;Liu et al, 2010). Potential explanations for the seasonal GOM trend include, the influence of point sources (Rutter et al, 2007), increase oxidation of GEM due to the seasonal variation of atmospheric oxidants (Selin and Jacob, 2008;Liu et al, 2010), and free troposphere transport ).…”

Section: Seasonal Concentrationsmentioning

confidence: 99%

Concentration-weighted trajectory approach to identifying potential sources of speciated atmospheric mercury at an urban coastal site in Nova Scotia, Canada

Cheng¹,

et al. 2013

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Regional and local sources contributing to gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particle-bound mercury (PBM) at an urban coastal site in Dartmouth, Nova Scotia, Canada were investigated using the Concentration-Weighted Trajectory model (CWT) and Conditional Probability Function. From 2010–2011, GEM, GOM, and PBM concentrations were 1.67 ± 1.01 ng m⁻³, 2.07 ± 3.35 pg m⁻³, and 2.32 ± 3.09 pg m⁻³, respectively. Seasonal variability was observed, with statistically higher GEM and PBM concentrations in winter and spring and higher GOM in spring. In the CWT, concentrations are the weighting factors for the trajectory residence time in modeled grid cells, which results in the identification of source areas based on the CWT values in the grid cells. Potential source areas were identified in regions with known industrial Hg sources particularly in the fall season, but also in regions without these sources (e.g. Atlantic Ocean, northern Ontario and Quebec). CWTs for GOM and PBM that were associated with ≥ 5 kg industrial Hg emissions from 2010–2011 were statistically larger than those with zero Hg emissions, despite a lack of strong correlations. A large proportion of elevated CWTs (85–97%) was in regions with zero industrial Hg sources indicating the potential role of non-point sources, natural emissions, and residential-scale combustion. Analysis of wind data suggests that a commercial harbor and vehicular traffic were potential local sources. Evaluating modeled source areas against Hg emissions inventories was not an ideal method for assessing the CWT model accuracy because of insufficient data on Hg emissions at more precise locations

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“…Such concentration spikes (≥15.0 ng m À3 and up to 30.1 ng m À3 ) occurred in short durations (<30 min) and were commonly observed at urban sites [Feng et al, 2004;Friedli et al, 2011;Song et al, 2009]. These events were associated with different wind directions and speeds, suggesting different emission sources.…”

Section: Transient High-tgm Eventsmentioning

confidence: 99%

Characteristics and potential sources of atmospheric mercury at a subtropical near‐coastal site in East China

et al. 2015

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To evaluate the impact of regional mercury (Hg) emissions and understand possible source regions of atmospheric Hg in Eastern China, 2 year observation for speciated atmospheric Hg was conducted at the Dameishan Atmospheric Observatory, a mountain site near the east coast of China. The observed concentration of total gaseous Hg (TGM) was 3.3 ± 1.4 ng m À3 . During the sampling period, gaseous oxidized Hg and particulate bound Hg were 6.7 ± 4.3 pg m À3 and 180 ± 110 pg m À3 in winter and 5.9 ± 3.4 pg m À3 and 130 ± 100 pg m À3 in spring, respectively. The relatively high mean concentration of TGM was mainly caused by regional anthropogenic emissions and occasional long-range transport from domestic source regions. Seasonal variation in the TGM concentration was observed with lower values in the wet monsoon season (from May to September) and higher values in the dry monsoon season (from October to April). Backward trajectories and potential source contribution function analysis suggested that anthropogenic Hg emission from coal combustion in the Yangtze River Delta region was the most likely cause for the elevated TGM concentrations. Relatively clean air originating from the East China Sea was the most possible cause for the observed low TGM concentrations. Positive correlation between TGM concentration and air quality index suggests that emissions that influenced regional air quality contributed to the elevated TGM concentrations.

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Annual atmospheric mercury species in Downtown Toronto, Canada

Cited by 64 publications

References 36 publications

Seasonal and Diurnal Variations of Total Gaseous Mercury in Urban Houston, TX, USA

Seasonal and Diurnal Variations of Total Gaseous Mercury in Urban Houston, TX, USA

Concentration-weighted trajectory approach to identifying potential sources of speciated atmospheric mercury at an urban coastal site in Nova Scotia, Canada

Characteristics and potential sources of atmospheric mercury at a subtropical near‐coastal site in East China

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