Annual and seasonal trends in mercury deposition in Maryland

Lawson, Nicole; Sheu, Guey Rong

doi:10.1016/s1352-2310(99)00428-8

Cited by 97 publications

(49 citation statements)

References 29 publications

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“…MeHg generally accounts for ∼ 0.5-3.0 % of THg in precipitation (Mason et al, 2000;St. Louis et al, 2005;Nguyen et al, 2005;Munthe et al, 1995a, b), but the proportion can be > 10 % in single event (St. Louis et al, 2005;Hall et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

“…Numerous studies suggested that atmospheric deposition is the primary source of Hg to terrestrial and aquatic ecosystems (Lombard et al, 2011), such as Great Lakes (Fitzgerald et al, 1991;Landis and Keeler, 2002), remote inland lakes (Sorensen et al, 1990) and forested catchments (Munthe et al, 1995a). Some other studies considered atmospheric deposition of MeHg to be a minor contributor to the aquatic ecosystem (Mason et al, 2000), while some investigators argued that wet deposition could be an important source of MeHg for certain ecosystems (Munthe et al, 1995b;Rolfhus et al, 2003), such as upland watershed at the ELA (St. Louis et al, 1994).…”

Section: Introductionmentioning

confidence: 99%

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Spatial and temporal distributions of total and methyl mercury in precipitation in core urban areas, Chongqing, China

Wang

Meng

et al. 2012

Atmos. Chem. Phys.

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Abstract. The spatial and temporal distribution patterns of mercury (Hg) in precipitation were investigated in the core urban areas of Chongqing, China. During the period from July 2010 to June 2011, total mercury (THg) and methyl mercury (MeHg) concentrations in precipitation were analysed from three sampling sites. Our results suggested that the volume-weight mean THg and MeHg concentrations in precipitation were 30.67 ng l −1 and 0.31 ng l −1 , respectively. The proportion of MeHg in THg ranged from 0.1 % to 7.6 % with a mean value of 1.3 %. THg and MeHg concentrations showed seasonal variations, while the highest THg value was measured in winter. Contrarily, the highest MeHg concentration was observed in autumn. Additionally, a geographically gradual decline of THg concentration in precipitation was observed from the downtown to the suburb, then to the controlled site in the city. 5 mm rainfall might be a threshold for the full wash-out capability. Rainfall above 5 mm may have a diluting effect for the concentrations of THg. Moreover, the current research implies that the coal combustion and motor vehicles could be the dominant sources for Hg in the precipitation.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Spatial and temporal distributions of total and methyl mercury in precipitation in core urban areas, Chongqing, China

Wang

Meng

et al. 2012

Atmos. Chem. Phys.

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“…In North America seasonal patterns in wet deposition are observed in both depositional flux and concentration with the highest values in the summer and lowest values in the winter (Sorensen et al, 1994;Mason et al, 2000;Guentzel et al, 2001;Keeler et al, 2005;VanArsdale et al, 2005;Choi et al, 2008;Prestbo and Gay, 2009). Explanations for this observation include more effective Hg scavenging by rain compared to snow (Sorensen et al, 1994;Mason et al, 2000;Keeler et al, 2005;Selin and Jacob, 2008), a greater availability of soluble Hg due to convective transport in summer events (Guentzel et al, 2001;Keeler et al, 2005), and a summer increase in Hg-containing soil derived particles in the atmosphere (Sorensen et al, 1994).…”

Section: Introductionmentioning

confidence: 99%

“…Inconsistent results are reported in studies comparing Hg wet deposition fluxes and/or concentrations between rural and urban sites. Some report elevated annual fluxes (Mason et al, 2000) and concentrations (Steding and Flegal, 2002;Engle et al, 2010) at urban locations while others report no significant differences in mean concentrations (Sorensen et al, 1994;Guentzel et al, 2001;Hall et al, 2005). Gaseous evasion of Hg • from marine waters is a significant global source of atmospheric Hg and may also contribute to elevated depositional fluxes in coastal regions (Mason and Sheu, 2002).…”

Section: Introductionmentioning

confidence: 99%

Mercury deposition in Southern New Hampshire, 2006–2009

et al. 2011

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Abstract. The atmospheric deposition of mercury (Hg) occurs via several mechanisms including wet, dry, and occult processes. In an effort to understand the atmospheric cycling and seasonal depositional characteristics of Hg, event-based wet deposition samples and reactive gaseous Hg (RGM) measurements were collected for approximately 3 years at Thompson Farm (TF), a near-coastal rural site in Durham, NH, part of the University of New Hampshire AIRMAP Observing Network. Total aqueous mercury exhibited seasonal patterns in Hg wet deposition at TF. The lowest Hg wet deposition was measured in the winter with an average total seasonal deposition of 1.56 µg m −2 compared to the summer average of 4.71 µg m −2 . Inter-annual differences in total wet deposition are generally linked with precipitation volume, with the greatest deposition occurring in the wettest year. Relationships between surface level RGM and Hg wet deposition were also investigated based on continuous RGM measurements at TF from November 2006 to September 2009. No correlations were observed between RGM mixing ratios and Hg wet deposition, however the ineffective scavenging of RGM during winter precipitation events was evidenced by the less frequent depletion of RGM below the detection level. Seasonal dry deposition of reactive gaseous Hg (RGM) was estimated using an order-of-magnitude approach. RGM mixing ratios and dry deposition estimates were greatest during the winter and spring. The seasonal ratios of Hg wet deposition to RGM dry deposition vary by up to a factor of 80.

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“…Bay, Japan during the 1950s and 1960s, specific concern has been given to the bioaccumulation of methyl mercury, one of mercury's most toxic forms, especially through the consumption of fish 7,[16][17][18] . This concern is highlighted by the number of fish consumption guidelines issued by several industrialised countries and in a recent paper concerned about the effect of low-level environmental mercury on human health 19 .…”

Section: Introductionmentioning

confidence: 99%

An analysis of total gaseous mercury (TGM) concentrations across the UK from a rural sampling network

2011

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Total gaseous mercury was collected at ten sites which comprise part of the UK rural . Using data from nine of the sites, we were able to show seasonality within the data and through kriging we were able to interpolate the TGM concentrations over the UK, revealing a south-east to north-west declining concentration gradient. Using continuous speciated mercury measurements from one of the network sites, we show through wind sector analysis and air-mass back trajectories that this spatial trend is likely to be due to air masses moving over the UK from continental Europe on easterly winds. The levels of TGM recorded in the south-east of the UK also more closely match observed background TGM levels on the continent, which could indicate that the TGM concentrations from the north of the UK are a better reflection of the true North Atlantic atmospheric mercury background level.

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Annual and seasonal trends in mercury deposition in Maryland

Cited by 97 publications

References 29 publications

Spatial and temporal distributions of total and methyl mercury in precipitation in core urban areas, Chongqing, China

Spatial and temporal distributions of total and methyl mercury in precipitation in core urban areas, Chongqing, China

Mercury deposition in Southern New Hampshire, 2006–2009

An analysis of total gaseous mercury (TGM) concentrations across the UK from a rural sampling network

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