A5054160097- Mercury impact and mitigation studies
- Toxic Organic Pollutants Impact
- Heavy metals in environment
- Water Treatment and Disinfection
- Aeolian processes and effects
- Marine animal studies overview
- Fire effects on ecosystems
- Atmospheric and Environmental Gas Dynamics
- Geology and Paleoclimatology Research
- Isotope Analysis in Ecology
- Groundwater flow and contamination studies
Scripps Institution of Oceanography
2023-2025
Stockholm University
2020-2025
University of California, San Diego
2025
In surface waters, photodegradation is a major abiotic removal pathway of the neurotoxin monomethylmercury (MMHg), acting as key control on amounts MMHg available for biological uptake. Different environmental factors can alter rate photodegradation. However, our understanding how pathways in complex matrixes along land-to-ocean aquatic continuum respond to changes salinity, dissolved organic carbon (DOC) concentration and matter (DOM) composition incomplete. set laboratory experiments...
Photochemical demethylation of dimethylmercury (DMHg) could potentially be an important source monomethylmercury (MMHg) in sunlit water. Whether or not DMHg is photochemically degraded when dissolved water is, however, debated. While early study suggested natural waters to readily degrade, later work claimed stable seawater under sunlight and that observations may due experimental artifacts. Here, we present data showing by photochemical processes different (including from a DOC-rich stream,...
Potential degradation pathways of dimethylmercury (DMHg) remain as one the critical knowledge gaps in marine biogeochemical cycle mercury (Hg). Although Hg is known to be highly reactive with reduced sulfur, demethylation DMHg presence sulfide has until now remained experimentally untested. Here, we provide first experimental support for monomethylmercury (MMHg) both dissolved and mackinawite (FeS(s)m). The was shown pH dependent, higher rates at 9 than 5. At room temperature environmentally...
The anhydrosugars, levoglucosan, mannosan and galactosan, are regarded as suitable molecular indicators of natural biomass combustion. Here, we evaluate summed anhydrosugars (SAS) a paleofire indicator in 6000 year-long fossil core from Agios Floros fen, Peloponnese, Greece, by analyzing charcoal fragments parallel, throughout the sediment sequence. Modern surface soil samples same region were analysed for presence SAS, confirming biomarker an recent fire activity. highest SAS concentrations...
Abstract Mono‐ and dimethylmercury (MMHg DMHg, respectively) are the two primary organic forms of mercury (Hg) found in natural waters. While experimental approaches to characterize environmental behavior MMHg inorganic Hg widely used today, few laboratories conduct studies entailing use DMHg. In this paper, we have evaluated developed different analytical quantify DMHg laboratory studies. We demonstrate that can be analyzed from samples where is derivatized using sodium tetraethyl borate...
<p>Dimethylmercury (DMeHg), a highly toxic form of mercury (Hg), appears as dissolved gas in marine waters well some terrestrial environments. Although DMeHg does not reach concentrations natural environments that are direct concern for human and wildlife health, it has been suggested could play role controlling the amount monomethylmercury (MMeHg) available. As MMeHg bioaccumulates aquatic food webs to concern, links occurrence systems with negative consequences Hg pollution...
<p>In marine systems, the methylated mercury pool is approximately evenly distributed between monomethylmercury (MMHg) and dimethylmercury (DMHg). While MMHg well-studied due to its direct link with Hg accumulation in aquatic food webs, there a general lack of knowledge processes controlling DMHg formation or degradation. By acting as net sink source for MMHg, may exert control over concentrations subsequent bioaccumulation fish seafood ways currently not...
<p>Photochemical degradation of dimethylmercury (DMHg) could constitute an important source monomethylmercury (MMHg) in surface waters, thus impacting Hg bioaccumulation and exposure risks. Despite this, few have studied this process, no consensus has been reached on whether DMHg photodegradation occurs nature. We used isotope labeling techniques to study MMHg natural waters when exposed artificial UV light. Our results confirm that degrades at rates comparable those for a...