A5047507514- Mercury impact and mitigation studies
- Toxic Organic Pollutants Impact
- Atmospheric chemistry and aerosols
- Heavy metals in environment
- Atmospheric and Environmental Gas Dynamics
- Marine animal studies overview
- Air Quality and Health Impacts
- Pesticide and Herbicide Environmental Studies
- Heavy Metal Exposure and Toxicity
- Atmospheric Ozone and Climate
- Indigenous Studies and Ecology
- Isotope Analysis in Ecology
- Climate change and permafrost
- Cryospheric studies and observations
- Urban Stormwater Management Solutions
- Peatlands and Wetlands Ecology
- Methane Hydrates and Related Phenomena
- Pharmaceutical and Antibiotic Environmental Impacts
- Radioactivity and Radon Measurements
- Groundwater and Isotope Geochemistry
- Analytical chemistry methods development
- Geochemistry and Elemental Analysis
- Environmental Toxicology and Ecotoxicology
- Precipitation Measurement and Analysis
- Pesticide Residue Analysis and Safety
Environment and Climate Change Canada
2006-2017
University of Ottawa
2000-2012
Direction de la Recherche Technologique
2012
GDG Environnement
2007-2009
Trent University
2008
University of Alberta
2008
University of Manitoba
2008
Instituto de Investigacao das Pescas e do Mar
2008
Acadia University
2008
Université du Québec à Montréal
1992-2005
Diffuse anthropogenic and naturally mercury‐enriched areas represent long‐lived sources of elemental mercury to the atmosphere. The Nevada Study Tests Release Mercury From Soils (STORMS) project focused on measurement emissions from a enriched area. During project, concurrent measurements fluxes substrate were made September 1–4, 1997, using four micrometeorological methods seven field flux chambers. Ambient air concentrations ranged 2 nearly 200 ng m −3 indicating that site is source...
Abstract. Global emissions of mercury continue to change at the same time as Arctic is experiencing ongoing climatic changes. Continuous monitoring atmospheric provides important information about long-term trends in balance between transport, chemistry, and deposition this pollutant atmosphere. Ten-year records total gaseous (TGM) from 2000 2009 were analyzed two high sites Alert (Nunavut, Canada) Zeppelin Station (Svalbard, Norway); one sub-Arctic site Kuujjuarapik (Nunavik, Québec,...
As part of an international Hg flux intercomparison at the Steamboat Springs, Nevada, geothermal area, several dynamic soil chambers and micrometeorological gradient systems were operated over desert soils in early September 1997. A series unanticipated convective rain cells impacted site with first rainfall ∼90 days, initial 4‐cm increased moisture from ∼0.01 to 0.06% (vol/vol). Several operating prior events, two deployed wet following rainfall. Rainfall resulted immediate steep rise...
The paper presents an analysis of a set data that includes both Hg profiles and modeled fluxes over water surface (using the two-layer model) develops some insights regarding mercury water−air exchanges in Lake Ontario Upper St. Lawrence River (USLR). This first situ estimation gas exchange Ontario. It shows contributed to atmospheric built-up bodies. TGM concentrations were significantly higher on South shore than North shore, whereas degree saturation was shore. Moreover bodies reference...
Atmospheric mercury speciation and deposition are critical to understanding the fate of in environment. The importance atmospheric was investigated during an intensive field campaign Bay St. François wetlands late summer 2002. Measured gaseous elemental (GEM), reactive (RGM), particulate (PM: 0.1–2.5 μm) concentrations were 0.85–2.16 ng/m 3 (average 1.38 ), 0–22 pg/m 3.63 0.5–18 6.44 respectively. PM RGM represented <1% total mercury. We reported first synchronized automated...
Distribution of total mercury (THg), gaseous elemental Hg(0) (GEM), monomethyl Hg (MMHg), and dimethyl (DMHg) was examined in marine waters the Canadian Arctic Archipelago (CAA), Hudson Strait, Bay. Concentrations THg were low throughout water column all regions sampled (mean ± standard deviation; 0.40 0.47 ng L−1). MMHg also generally at surface (23.8 9.9 pg L−1); however mid- bottom depths, present concentrations sufficient to initiate bioaccumulation through foodwebs (maximum 178 L−1;...
The Canadian Atmospheric Network for Currently Used Pesticides (CANCUP) was the first comprehensive, nationwide air surveillance study of pesticides in Canada. This paper presents atmospheric occurrence and distribution including organochlorine (OCPs), organophosphate (OPPs), acid herbicides (AHs), neutral (NHs) during spring to summer 2004 2005 across agricultural regions concentrations varied within years time periods, regional characteristics were observed following: (i) highest several...
An extensive mercury study was conducted in April 2002 prior to and during the annual melting of a snowpack sub‐arctic site along Hudson Bay (Canada). Gas‐phase measurements show that snowmelt coincides with an elemental (Hg°) pulse air far above ambient levels. Additional inorganic (Hg 2+ ) methylmercury (MeHg + snow pits, surface meltwater sample clearly reveal most Hg is removed from first days snowmelt. We estimate gas‐phase exchanges contribute poorly remove snowpack; consequently day...
This paper presents mercury (Hg) concentrations and foliage/atmosphere fluxes in a maple forest ecosystem southern Québec, Canada. The average total gaseous (TGM) concentration measured at an open field site was significantly (p < 0.001) higher than that adjacent site, some 300 m away (1.40 ng −3 versus 1.03 , respectively). Foliage/atmosphere flux of TGM, with dynamic bag device, indicated deposition 0.39 ± 0.38 −2 h −1 the tree foliage. Although, bi‐directional Hg were observed,...
Tundra ecosystems store vast amounts of soil organic carbon, which may be sensitive to climatic change. Net ecosystem production, NEP, is the net exchange carbon dioxide (CO2) between landscapes and atmosphere, represents balance CO2 uptake by photosynthesis release decomposition autotrophic respiration. Here we examine across seven sites in Canadian low high Arctic during peak growing season (July) summer 2008. All were sinks for atmospheric (NEP ranged from 5 67 g C m–2), with being...
Abstract. An unknown fraction of mercury that is deposited onto snowpacks revolatilized to the atmosphere. Determining important since enters snowpack meltwater may be converted highly toxic bioaccumulating methylmercury. In this study, we present a new dynamic physically-based snowpack/meltwater model for suitable large-scale atmospheric models mercury. It represents primary physical and chemical processes determine fate snowpacks. The was implemented in Environment Canada's GRAHM. For...
Elemental Hg (Hg 0 ) is a volatile species that responsible for water-to-air transfer of in Lake Ontario and the St. Lawrence River. We conducted two cruises 1998 to identify spatial temporal patterns levels these systems performed field laboratory experiments on redox transformations Hg. concentrations were higher than At stations Ontario, at bottom water column surface, whereas they homogeneous throughout river. generally July September and, contrast with inland lakes, relatively constant...