An assessment of atmospheric mercury in the Community Multiscale Air Quality (CMAQ) model

Abstract. Quantitative analysis of three atmospheric mercury species – gaseous elemental mercury (Hg0), reactive gaseous mercury (RGHg) and particulate mercury (PHg) – has been limited to date by lack of ambient measurement data as well as by uncertainties in numerical models and emission inventories. This study employs the Community Multiscale Air Quality Model version 4.6 with mercury chemistry (CMAQ-Hg), to examine how local emissions, meteorology, atmospheric chemistry, and deposition affect mercury concentration and deposition the Great Lakes Region (GLR), and two sites in Wisconsin in particular: the rural Devil's Lake site and the urban Milwaukee site. Ambient mercury exhibits significant biases at both sites. Hg0 is too low in CMAQ-Hg, with the model showing a 6% low bias at the rural site and 36% low bias at the urban site. Reactive mercury (RHg = RGHg + PHg) is over-predicted by the model, with annual average biases >250%. Performance metrics for RHg are much worse than for mercury wet deposition, ozone (O3), nitrogen dioxide (NO2), or sulfur dioxide (SO2). Sensitivity simulations to isolate background inflow from regional emissions suggests that oxidation of imported Hg0 dominates model estimates of RHg at the rural study site (91% of base case value), and contributes 55% to the RHg at the urban site (local emissions contribute 45%).

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In situ measurements of speciated atmospheric mercury and the identification of source regions in the Mexico City Metropolitan Area

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-207-2009 ◽

2009 ◽

Vol 9 (1) ◽

pp. 207-220 ◽

Cited By ~ 63

Author(s):

A. P. Rutter ◽

D. C. Snyder ◽

E. A. Stone ◽

J. J. Schauer ◽

R. Gonzalez-Abraham ◽

...

Keyword(s):

Point Source ◽

Mexico City ◽

Metropolitan Area ◽

Atmospheric Mercury ◽

Point Sources ◽

Rural Site ◽

Urban Site ◽

Trajectory Data ◽

Source Regions ◽

Rural Sites

Abstract. In order to expand the currently limited understanding of atmospheric mercury source-receptor relationships in the Mexico City Metropolitan Area, real time measurements of atmospheric mercury were made at a downtown urban site, and a rural site on the outskirts of Mexico City, during March 2006. Numerous short-lived increases in particulate mercury (PHg) and reactive gaseous mercury (RGM) concentrations were observed at the urban site during the 17 day study, and less frequent increases in gaseous elemental mercury (GEM) concentrations were measured at both the urban and rural sites. The episodic increases observed were attributed to plume impacts from industrial point source emissions in and around Mexico City. Average concentrations and standard deviations measured during the study were as follows: i) urban site; PHg=187±300 pg m−3, RGM=62±64 pg m−3, GEM=7.2±4.8 ng m−3, and; ii) rural site; GEM=5.0±2.8 ng m−3. Several source regions of atmospheric mercury to the urban and rural sites were determined using Concentration Field Analysis, in which atmospheric mercury measurements were combined with back trajectory data to determine source regions. Only some source regions correlated to mercury emission sources listed in the Federal Pollutant Release and Transfer Register, leaving the rest unaccounted for. Contributions of anthropogenic mercury point sources in and around Mexico City to concentration averages measured at the urban site during the study were estimated to be: 93±3% of reactive mercury (PHg and RGM), and; 81±0.4% of GEM. Point source contributions to GEM measured at the rural site were 72±1%. GEM and reactive mercury (PHg+RGM) were not found to correlate with biomass burning at either of the measurement sites.

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The impact of biomass burning and aqueous-phase processing on air quality: a multi-year source apportionment study in the Po Valley, Italy

10.5194/acp-2019-274 ◽

2019 ◽

Cited By ~ 1

Author(s):

Marco Paglione ◽

Stefania Gilardoni ◽

Matteo Rinaldi ◽

Stefano Decesari ◽

Nicola Zanca ◽

...

Keyword(s):

Air Quality ◽

Source Apportionment ◽

Biomass Burning ◽

Organic Aerosol ◽

Cold Season ◽

World Health ◽

Rural Site ◽

Urban Site ◽

Urban Background ◽

Po Valley

Abstract. The Po Valley (Italy) is a well-known air quality hotspot characterized by Particulate Matter (PM) levels well above the limit set by the European Air Quality Directive and by the World Health Organization, especially during the colder season. In the framework of the Emilia-Romagna regional project SUPERSITO, the southern Po Valley submicron aerosol chemical composition was characterized by means of High-Resolution Aerosol Mass Spectroscopy (HR-AMS) with the specific aim of organic aerosol (OA) characterization and source apportionment. Eight intensive observation periods (IOPs) were carried out over four years (from 2011 to 2014) at two different sites (Bologna, BO, urban background and San Pietro Capofiume, SPC, rural background), to characterize the spatial variability and seasonality of the OA sources, with a special focus on the cold season. On the multi-year basis of the study, the AMS observations show that OA accounts for an average 45 ± 8 % (ranging 33–58 %) and 46 ± 7 % (ranging 36–50 %) of the total non-refractory submicron particle mass (PM1-NR) at the urban and at the rural site, respectively. Primary organic aerosol (POA) comprises biomass burning (23 ± 13 % of OA) and fossil fuel (12 ± 7 %) contributions with a marked seasonality in concentration. As expected, the biomass burning contribution to POA is more significant at the rural site (urban/rural concentrations ratio of 0.67), but it is also an important source of POA at the urban site during the cold season, with contributions ranging from 14 to 38 % of the total OA mass. Secondary organic aerosol (SOA) contribute to OA mass to a much larger extent than POA at both sites throughout the year (69 ± 16 % and 83 ± 16 % at urban and rural, respectively), with important implications for public health. Within the secondary fraction of OA, the measurements highlight the importance of biomass burning ageing products during the cold season, even at the urban background site. This biomass burning SOA fraction represents 14–44 % of the total OA mass in the cold season, indicating that in this region a major contribution of combustion sources to PM mass is mediated by environmental conditions and atmospheric reactivity. Among the environmental factors controlling the formation of SOA in the Po Valley, the availability of liquid water in the aerosol was shown to play a key role in the cold season. We estimate that organic fraction originating from aqueous reactions of biomass burning products (bb-aqSOA) represents 21 % (14–28 %) and 25 % (14–35 %) of the total OA mass and 44 % (32–56 %) and 61 % (21–100 %) of the SOA mass at the urban and rural sites, respectively.

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The impact of biomass burning and aqueous-phase processing on air quality: a multi-year source apportionment study in the Po Valley, Italy

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-1233-2020 ◽

2020 ◽

Vol 20 (3) ◽

pp. 1233-1254 ◽

Cited By ~ 5

Author(s):

Marco Paglione ◽

Stefania Gilardoni ◽

Matteo Rinaldi ◽

Stefano Decesari ◽

Nicola Zanca ◽

...

Keyword(s):

Air Quality ◽

Source Apportionment ◽

Biomass Burning ◽

Organic Aerosol ◽

Cold Season ◽

Rural Site ◽

Urban Site ◽

Urban Background ◽

Po Valley ◽

Rural Sites

Abstract. The Po Valley (Italy) is a well-known air quality hotspot characterized by particulate matter (PM) levels well above the limit set by the European Air Quality Directive and by the World Health Organization, especially during the colder season. In the framework of Emilia-Romagna regional project “Supersito”, the southern Po Valley submicron aerosol chemical composition was characterized by means of high-resolution aerosol mass spectroscopy (HR-AMS) with the specific aim of organic aerosol (OA) characterization and source apportionment. Eight intensive observation periods (IOPs) were carried out over 4 years (from 2011 to 2014) at two different sites (Bologna, BO, urban background, and San Pietro Capofiume, SPC, rural background), to characterize the spatial variability and seasonality of the OA sources, with a special focus on the cold season. On the multi-year basis of the study, the AMS observations show that OA accounts for averages of 45±8 % (ranging from 33 % to 58 %) and 46±7 % (ranging from 36 % to 50 %) of the total non-refractory submicron particle mass (PM1-NR) at the urban and rural sites, respectively. Primary organic aerosol (POA) comprises biomass burning (23±13 % of OA) and fossil fuel (12±7 %) contributions with a marked seasonality in concentration. As expected, the biomass burning contribution to POA is more significant at the rural site (urban / rural concentration ratio of 0.67), but it is also an important source of POA at the urban site during the cold season, with contributions ranging from 14 % to 38 % of the total OA mass. Secondary organic aerosol (SOA) contributes to OA mass to a much larger extent than POA at both sites throughout the year (69±16 % and 83±16 % at the urban and rural sites, respectively), with important implications for public health. Within the secondary fraction of OA, the measurements highlight the importance of biomass burning aging products during the cold season, even at the urban background site. This biomass burning SOA fraction represents 14 %–44 % of the total OA mass in the cold season, indicating that in this region a major contribution of combustion sources to PM mass is mediated by environmental conditions and atmospheric reactivity. Among the environmental factors controlling the formation of SOA in the Po Valley, the availability of liquid water in the aerosol was shown to play a key role in the cold season. We estimate that the organic fraction originating from aqueous reactions of biomass burning products (“bb-aqSOA”) represents 21 % (14 %–28 %) and 25 % (14 %–35 %) of the total OA mass and 44 % (32 %–56 %) and 61 % (21 %–100 %) of the SOA mass at the urban and rural sites, respectively.

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A Local Scale Modeling Study of Mercury Depletion Event at Canadian Arctic

10.32920/ryerson.14647020 ◽

2021 ◽

Author(s):

Minish Panchall

Keyword(s):

Measurement Data ◽

Canadian Arctic ◽

Elemental Mercury ◽

Local Scale ◽

Atmospheric Mercury ◽

Scale Model ◽

Mercury Species ◽

Time Step ◽

Gaseous Elemental Mercury ◽

Modeling Study

A modeling study was conducted on the transformation and deposition patterns of atmospheric mercury in the Canadian Arctic. One Dimensional (1-D) local scale model was used to simulate the episodic depletions of gaseous elemental mercury (GEM) after polar sunrise at Alert, Canada. The model was developed by starting with existing meteorological model (LCM-Local Climate Model) which is coupled with Canadian Aerosol Module (CAM) and then adding modules specific to atmospheric mercury chemistry. The model is able to simulate local scale transport of mercury over the entire depth of the troposphere with a basic time step of 20 min. and incorporates current knowledge of transformation reactions of atmospheric mercury species. Three mercury species Hg(O), Hg(II) and Hg(p) were considered. The developed model was applied to a portion of the Canadian Arctic region, Alert, for the month of April 2002. The model was then evaluated by comparing model estimates of mercury species concentrations with the measurement data collected in the Canadian Arctic by Meteorological Services of Canada, Downsview, Ontario. The results from this modeling study agree reasonably well with some underestimation caused by lower conversion of gaseous elemental mercury (GEM) into reactive gaseous mercury (RGM) and subsequent conversion to total particulate mercury (TPM). A sensitivity analysis was also conducted to examine the depositions of mercury species in response to changes in ozone and soot concentrations.

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Comparison of Atmospheric Mercury Speciation at a Coastal and an Urban Site in Southeastern Texas, USA

Atmosphere ◽

10.3390/atmos11010073 ◽

2020 ◽

Vol 11 (1) ◽

pp. 73 ◽

Cited By ~ 3

Author(s):

Travis Griggs ◽

Lei Liu ◽

Robert W. Talbot ◽

Azucena Torres ◽

Xin Lan

Keyword(s):

Northern Hemisphere ◽

Background Level ◽

Elemental Mercury ◽

Atmospheric Mercury ◽

Urban Site ◽

Mercury Species ◽

Mixing Ratio ◽

Coastal Site ◽

Mixing Ratios ◽

The Relationship

Sixteen months of continuous measurements and the analysis of atmospheric mercury (gaseous elemental mercury GEM, gaseous oxidized mercury GOM, and particulate bound mercury PBM) under urban and coastal settings were conducted in Southeastern Texas. At the urban site, the GEM mean mixing ratio was 185 ppqv, 5%–10% higher than the Northern Hemisphere GEM background level. GOM and PBM mixing ratios were as much as six times higher than their background level. The coastal site GEM mean mixing ratio was 165 ppqv, higher than other coastal sites located in the Northern Hemisphere. GOM and PBM mean mixing ratios at the coastal site were 0.75 ppqv and 0.58 ppqv. The urban site had a higher frequency of high mercury events (>300 ppqv) compared to the coastal site. The diurnal patterns were found for both sites: In the urban environment, GEM accumulated to the maximum mixing ratio just after sunrise and decreased to the minimum mixing ratio in late afternoon. In the coastal environment, GEM decreased at night reaching its minimum mixing ratio before sunrise. The relationship between atmospheric mercury species and meteorological parameters was investigated. An examination of the relationship between atmospheric mercury species and key trace gases was conducted as well, showing that the concurrence of GEM, CO2, CO, CH4, and SO2 maximum mixing ratios was notable and provided evidence they may originate from the same emission source. The coastal site was at times influenced by polluted air from urban Houston and the cleaner Gulf of Mexico marine air at other times.

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A Local Scale Modeling Study of Mercury Depletion Event at Canadian Arctic

10.32920/ryerson.14647020.v1 ◽

2021 ◽

Author(s):

Minish Panchall

Keyword(s):

Measurement Data ◽

Canadian Arctic ◽

Elemental Mercury ◽

Local Scale ◽

Atmospheric Mercury ◽

Scale Model ◽

Mercury Species ◽

Time Step ◽

Gaseous Elemental Mercury ◽

Modeling Study

A modeling study was conducted on the transformation and deposition patterns of atmospheric mercury in the Canadian Arctic. One Dimensional (1-D) local scale model was used to simulate the episodic depletions of gaseous elemental mercury (GEM) after polar sunrise at Alert, Canada. The model was developed by starting with existing meteorological model (LCM-Local Climate Model) which is coupled with Canadian Aerosol Module (CAM) and then adding modules specific to atmospheric mercury chemistry. The model is able to simulate local scale transport of mercury over the entire depth of the troposphere with a basic time step of 20 min. and incorporates current knowledge of transformation reactions of atmospheric mercury species. Three mercury species Hg(O), Hg(II) and Hg(p) were considered. The developed model was applied to a portion of the Canadian Arctic region, Alert, for the month of April 2002. The model was then evaluated by comparing model estimates of mercury species concentrations with the measurement data collected in the Canadian Arctic by Meteorological Services of Canada, Downsview, Ontario. The results from this modeling study agree reasonably well with some underestimation caused by lower conversion of gaseous elemental mercury (GEM) into reactive gaseous mercury (RGM) and subsequent conversion to total particulate mercury (TPM). A sensitivity analysis was also conducted to examine the depositions of mercury species in response to changes in ozone and soot concentrations.

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In situ measurements of speciated atmospheric mercury and the identification of source regions in the Mexico City Metropolitan Area

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-8-13125-2008 ◽

2008 ◽

Vol 8 (4) ◽

pp. 13125-13157

Author(s):

A. P. Rutter ◽

D. C. Snyder ◽

E. A. Stone ◽

J. J. Schauer ◽

R. Gonzalez-Abraham ◽

...

Keyword(s):

Point Source ◽

Mexico City ◽

Metropolitan Area ◽

Atmospheric Mercury ◽

Point Sources ◽

Rural Site ◽

Urban Site ◽

Trajectory Data ◽

Source Regions ◽

Rural Sites

Abstract. In order to expand the currently limited understanding of atmospheric mercury source-receptor relationships in the Mexico City Metropolitan Area, real time measurements of atmospheric mercury were made at a downtown urban site, and a rural site on the outskirts of Mexico City, during March, 2006. Numerous short-lived increases in particulate mercury (PHg) and reactive gaseous mercury (RGM) concentrations were observed at the urban site during the 17 day study, and less frequent increases in gaseous elemental mercury (GEM) concentrations were measured at both the urban and rural sites. The episodic increases observed were attributed to plume impacts from industrial point source emissions in and around Mexico City. Average concentrations and standard deviations measured during the study were as follows: i) Urban site: PHg=187±300 pg m−3, RGM=62±64 pg m−3, GEM=7.2±4.8 ng m−3. ii) Rural site: GEM=5.0±2.8 ng m−3. Several source regions of atmospheric mercury to the urban and rural sites were determined using Concentration Field Analysis, in which atmospheric mercury measurements were combined with back trajectory data to determine source regions. Only some source regions correlated to mercury emission sources listed in the Federal Pollutant Release and Transfer Register, leaving the rest unaccounted for. Contributions of anthropogenic mercury point sources in and around Mexico City to concentration averages measured at the urban site during the study were estimated to be: 93±3% of reactive mercury (PHg and RGM), and; 81±0.4% of GEM. Point source contributions to GEM measured at the rural site were 72±1%. GEM and reactive mercury (PHg and RGM) were not found to correlate with biomass burning at either of the measurement sites.

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Salt Intake in Nigeria: a nationwide population survey

European Heart Journal ◽

10.1093/ehjci/ehaa946.2866 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

A.N Odili ◽

B.S Chori ◽

B Danladi ◽

P.C Nwakile ◽

J.O Ogedengbe ◽

...

Keyword(s):

Salt Intake ◽

Sodium Intake ◽

Population Analysis ◽

Cost Effective ◽

Rural Site ◽

Urban Site ◽

Funding Source ◽

Salt Reduction ◽

High Salt Intake ◽

The Impact

Abstract Background Population wide salt reduction programmes are cost effective strategies for control of cardiovascular diseases (CVDs). Obtaining a nationwide salt consumption data in a multi-cultural setting as Nigeria's is key for proper implementation and monitoring of such strategy. Methods We measured sodium in 24-hour urine of free-living adult Nigerians selected from an urban and a rural site each from the 6 geopolitical zones of Nigeria to evaluate patterns of salt intake and its associations with blood pressures (BP). Results Across the 12 sites, sodium intake ranged from 97.9 in the rural South-South to 210 mmol/day in the urban site of the same zone. Overall, the median (IQR) daily sodium intake was 143.5 (97.8) mmol; with higher (p=0.0028) levels among the urban 149.7 (113.8) compared to the rural 133.1 (105.2) dwellers. Overall, 20% of the subjects consumed less than the recommended 2g (86mmol) of sodium daily. After adjustment for age, sex and BMI; sodium intake and BP (systolic and diastolic) were positively associated in 8 out of the 12 sites; significantly so in 2 (p<0.05) for systolic. Within population analysis; which included 973 individuals, increasing sodium intake tended (not significantly) to increase SBP but decrease DBP. However, among subjects whose sodium intake was in excess of 257mmol/day, a 100 mmol/day increase in sodium intake was significantly (p=0.04) associated with a 3.3 mmHg increase in SBP. Conclusion Salt intake among Nigerians is higher than the recommended. The impact of sodium intake on BP appears to be evident only among individuals with high salt intake. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Wellcome Trust

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The Diamond League athletic series: does the air quality sparkle?

International Journal of Biometeorology ◽

10.1007/s00484-021-02114-z ◽

2021 ◽

Author(s):

James R. Hodgson ◽

Lee Chapman ◽

Francis D. Pope

Keyword(s):

Particulate Matter ◽

Air Quality ◽

Performance Metrics ◽

Urban Air Pollution ◽

Quality Data ◽

Performance Variation ◽

Short And Long Term ◽

Respiratory Conditions ◽

Race Performance

AbstractUrban air pollution can have negative short- and long-term impacts on health, including cardiovascular, neurological, immune system and developmental damage. The irritant qualities of pollutants such as ozone (O3), nitrogen dioxide (NO2) and particulate matter (PM) can cause respiratory and cardiovascular distress, which can be heightened during physical activity and particularly so for those with respiratory conditions such as asthma. Previously, research has only examined marathon run outcomes or running under laboratory settings. This study focuses on elite 5-km athletes performing in international events at nine locations. Local meteorological and air quality data are used in conjunction with race performance metrics from the Diamond League Athletics series to determine the extent to which elite competitors are influenced during maximal sustained efforts in real-world conditions. The findings from this study suggest that local meteorological variables (temperature, wind speed and relative humidity) and air quality (ozone and particulate matter) have an impact on athletic performance. Variation between finishing times at different race locations can also be explained by the local meteorology and air quality conditions seen during races.

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