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Pesticides are among the factors being proposed as causal agents for amphibian population declines in the Sierra Nevada range of California, USA. We hypothesize that agricultural pesticides applied in the San Joaquin Valley west of the mountains are volatilized or eroded, transpo...

An evaluation of the Regional Mercury Cycling Model (R-MCM, a steady-state fate and transport model used to simulate mercury concentrations in lakes) is presented based on its application to a series of 91 lakes in Vermont and New Hampshire. Visual and statistical analyses are pr...

Both human and ecosystem exposure studies evaluate exposure of sensitive and vulnerable populations. We will discuss how ecosystem exposure modeling studies completed for input into the US Clean Air Mercury Rule (CAMR) to evaluate the response of aquatic ecosystems to changes in ...

A divergence is predicted between the acidity behavior of charged sites on micron sized colloidal particles and nanoparticles. Utilizing the approximate analytical solution to the Poisson-Boltzmann equation published by Ohshima et al. (1982), findings from the work included: 1):...

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

Numerical models of atmospheric mercury are formulated based on the current understanding of mercury chemistry in air and in atmospheric water. Recent evidence that significant reduction of Hg2+ by reaction with HO2 may not actually occur in natural atmospheric water has obviou...

The selection of target fish species for assessing the extent of fish tissue contaminants is a critical consideration in regional stream surveys such as the Environmental Monitoring and Assessment Program (EMAP). The ideal species would be widely distributed and common, bioaccumu...

The problem of assessing risk from mercury across the nation is extremely complex involving integration of I) our understanding of the methylation process in ecosystems, 2) the identification and spatial distribution of sensitive populations, and 3) the spatial pattern of mercury...

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

Intensive field measurements of atmospheric mercury and related species were carried out in Ny Alesund, Spitsbergen during the spring of 2003 at two altitudes. Measurements were made at the Italian research station Dirigibile Italia (12m a.s.l.) and on the top of Zeppelin Mountai...

Wet and dry mercury (Hg) deposition were calculated to Lake Michigan using a hybrid receptor modeling framework. The model utilized mercury monitoring data collected during the Lake Michigan Mass Balance Study and the Atmospheric Exchange Over Lakes and Oceans Study together w...

The relative importance of the Chicago/Gay urban area was investigated to determine its impact on atmospheric mercury (Hg) concentrations and wet deposition in the Lake Michigan basin. Event wet-only precipitation, total particulate, and vapor phase samples were collected for ...

Environmental contamination from mercury has been recognized for decades as a growing problem to humans and wildlife. It is released from a variety of sources, exhibits a complicated chemistry, and proceeds via several different pathways to humans and wildlife. According to the...

National and international concern about the health effects and continued use of mercury (Hg) as well as other metals has defined the need for estimates of the long term risks to ecosystems and human health from Hg released from human activities. The atmosphere is one of the mec...

The Community Multiscale Air Quality (CMAQ) modeling system has recently been adapted to simulate the emission, transport, transformation and deposition of atmospheric mercury in three distinct forms; elemental mercury gas, reactive gaseous mercury, and particulate mercury. Emis...

The current state of our scientific understanding the mercury cycle tells us that most of the mercury getting into fish comes from atmospheric deposition, but methylation of that mercury in aquatic systems is required for the concentrations in fish to reach harmful levels. We st...

We present airborne observations of gaseous reactive halogen species (HCl, Cl2, ClNO2, Br2, BrNO2, and BrCl), sulfur dioxide (SO2), and nonrefractory fine particulate chloride (pCl) and sulfate (pSO4) in power plant exhaust. Measurements were conducted during the Wintertime INves...

A previous intercomparison of atmospheric mercury models in North America has been extended to compare simulated and observed wet deposition of mercury. Three regional-scale atmospheric mercury models were tested; CMAQ, REMSAD and TEAM. These models were each employed using thr...

Two modified passive samplers were evaluated at multiple field locations. The sampling rate (SR) of the modified polyurethane foam (PUF)-disk passive sampler for total gaseous mercury (TGM) using gold-coated quartz fiber filters (GcQFF) and gaseous oxidized mercury (GOM) using io...

This paper describes the development of a new artificial turf surrogate surface (ATSS) sampler for use in the measurement of mercury (Hg) dry deposition. In contrast to many existing surrogate surface designs, the ATSS utilizes a three-dimensional deposition surface that may more...

We demonstrate a novel, spatially explicit assessment of the current condition of aquatic ecosystem services, with limited sensitivity analysis for the atmospheric contaminant mercury. The Integrated Ecological Modeling System (IEMS) forecasts water quality and quantity, habitat ...

We demonstrate an Integrated Modeling Framework that predicts the state of freshwater ecosystem services within the Albemarle-Pamlico Basins. The Framework consists of three facilitating technologies: Data for Environmental Modeling (D4EM) that automates the collection and standa...

Freshwater habitats provide fishable, swimmable and drinkable resources and are a nexus of geophysical and biological processes. These processes in turn influence the persistence and sustainability of populations, communities and ecosystems. Climate change and landuse change enco...

We demonstrate an Integrated Modeling Framework that predicts the state of freshwater ecosystem services within the Albemarle-Pamlico Basins. The Framework consists of three facilitating technologies: Data for Environmental Modeling (D4EM) that automates the collection and standa...

The U.S. Environmental Protection Agency uses environmental models to inform rulemaking and policy decisions at multiple spatial and temporal scales. As decision-making has moved towards integrated thinking and assessment (e.g. media, site, region, services), the increasing compl...