A5025770901- Heavy metals in environment
- Environmental Toxicology and Ecotoxicology
- Geochemistry and Elemental Analysis
- Water Quality and Pollution Assessment
- Radioactive element chemistry and processing
- Marine and coastal ecosystems
- Mine drainage and remediation techniques
- Radioactive contamination and transfer
- Geochemistry and Geologic Mapping
- Atmospheric chemistry and aerosols
- Analytical chemistry methods development
- Polar Research and Ecology
- Groundwater and Isotope Geochemistry
- Geology and Paleoclimatology Research
- Ocean Acidification Effects and Responses
- Groundwater flow and contamination studies
- Aquatic Ecosystems and Phytoplankton Dynamics
- Aquatic Invertebrate Ecology and Behavior
- Marine Biology and Ecology Research
- Electrochemical Analysis and Applications
- Microbial Community Ecology and Physiology
- Cryospheric studies and observations
- Freshwater macroinvertebrate diversity and ecology
- Marine Bivalve and Aquaculture Studies
- Catalysis and Oxidation Reactions
University of Manchester
2011-2023
University of Leeds
2014-2021
UK Centre for Ecology & Hydrology
2010-2014
Université de Lorraine
2013
Lancaster University
2008-2010
University of Aberdeen
1996
Chelsea and Westminster Hospital
1984
Rising concentrations of atmospheric carbon dioxide are causing acidification the oceans. This results in changes to key chemical species such as hydroxide, carbonate and bicarbonate ions. These will affect distribution different forms trace metals. Using IPCC data for pCO2 pH under four future emissions scenarios (to year 2100) we use a speciation model predict organic inorganic Under scenario where peak after 2100, predicted free ion Al, Fe, Cu, Pb increase by factors up approximately 21,...
Abstract Melting of the Greenland Ice Sheet is a leading cause land-ice mass loss and cryosphere-attributed sea level rise. Blooms pigmented glacier ice algae lower albedo accelerate surface melting in sheet’s southwest sector. Although up to 13% this region, controls on bloom development remain poorly understood. Here we show direct link between mineral phosphorus biomass through quantification solid fluid phase reservoirs habitats across ablation zone sheet. We demonstrate that nutrients...
Significance Mineral dust is the most important external source of phosphorus (P), a key nutrient controlling phytoplankton productivity and carbon uptake, to offshore ocean. The bioavailable P in exhibits considerable poorly understood variability. Detailed laboratory experiments elucidate quantify major processes dissolution atmosphere. Dust exposure acids main driver mineral transformations, simple direct proportionality found between amount dissolved from acid exposure. Simulations...
Recent estimates of nutrient budgets for the Eastern Mediterranean Sea (EMS) indicate that atmospheric aerosols play a significant role as suppliers macro- and micro- nutrients to its Low Nutrient Chlorophyll water. Here we present first mesocosm experimental study examines overall response oligotrophic EMS surface mixed layer (Cretan Sea, May 2012) two different types natural aerosol additions, "pure" Saharan dust (SD, 1.6 mg l-1) (A - polluted desert origin, 1 l-1). We describe rationale,...
Glaciers and ice sheets are a significant source of nanoparticulate Fe, which is potentially important in sustaining the high productivity observed near-coastal regions proximal to terrestrial cover. However, bioavailability particulate iron poorly understood, despite its importance ocean Fe inventory. We combined high-resolution imaging spectroscopy investigate abundance, morphology valence state glacial sediments. Our results document widespread occurrence amorphous Fe(II)-rich...
Environmental context. Chemical characterisation of sediment microniches can reveal diagenetic processes that may not be detected by larger-scale analysis. With the development a new preparation method for binding phase gel, technique diffusive gradients in thin films has been used to demonstrate links between diagenesis sulfide, phosphorus, vanadium and arsenic at microniches. Knowledge these improve predictions past deposition climates where trace elements are considered as paleoredox...
The authors apply the chemical speciation model WHAM/Model VII to investigate distribution of metal species Fe(III) and divalent cations Ni, Cu, Zn, Cd, Hg, Pb, in water column estuaries coastal areas. compare, for same locations, measured modeled free ion organically bound concentrations. calculations show varying levels agreement with experimental measurements. Where only natural organic matter is considered as ligand, within 1 order magnitude found 122 128 comparisons. For Fe Zn...
Abstract The role of dust as a source bioavailable phosphorus (Bio‐P) is quantified using new parameterization for apatite dissolution in combination with global soil data maps and aerosol transport model. Mineral provides 31.2 Gg‐P/year Bio‐P to the oceans, 14.3 from labile P present dust, an additional 16.9 acid atmosphere, representing increase 120%. North Atlantic, northwest Pacific, Mediterranean Sea are identified important sites deposition mineral dust. process increases fraction...
Environmental contextThe chemical speciation of metals strongly influences their transport, fate and bioavailability in natural waters. Analytical measurement modelling both play important roles understanding speciation, while is also needed for prediction. Here, we analyse a large set data fresh waters, estuarine coastal open ocean water, to examine how well measurements predictions agree. AbstractWe compiled ~2000 published metal made on samples For each sample, applied the model WHAM7...
Acid processes in the atmosphere, particularly those caused by anthropogenic acid gases, increase amount of bioavailable P dust and hence are predicted to microbial biomass primary productivity when supplied oceanic surface waters. This is likely be important Eastern Mediterranean Sea (EMS), which limited during winter bloom N&P co-limited for phytoplankton summer. However, it not clear how acting on Saharan will affect EMS. Here, we carried out bioassay manipulations EMS water was added as...
Previous work used the sampling technique diffusive gradients in thin films analysed by laser ablation mass spectrometry to measure sulfide, P, V and As at a microniche of reactive organic carbon freshwater sediment. Here we present new developments this technique. The number analytes has been extended demonstrate for depth profiling both one two dimensions. physical dimensions cell unit restrict maximum length gel that can be analysed. We address problem proposing method obtaining better...
Environmental contextSpeciation of trace metals in the oceans is typically explained by invoking concept metal binding to specific organic ligands. Here, using a speciation model widely used for freshwaters, we assess extent which non-specific humic-type ligands found ocean may explain chemical cationic metals. We that can give good fits some cases, and experimental results do not consistent variation from model. This has implications way availability elements considered environments....
Antiemetic prophylaxis with high dose metoclopramide or lorazepam in vomiting induced by chemotherapy Emesis cytotoxic agents is an important side effect that may determine a patient's acceptance of cancer and be responsible for his defaulting from potentially effective treatment.Despite the availability several antiemetic drugs, this complication generally poorly controlled.Gralla et al found intravenous doses to anti- emetic agent, better than placebo prochlorperazine, chemo- therapy...
Environmental context. Modelling of discrete sites diagenesis in sediments (microniches) has typically been performed 1-D and involved a limited set components. Here we present new 3-D model for microniches within traditional vertical sequence redox reactions, show example modelled niches range sizes, close to the sediment–water interface. Microniche processes may have implications understanding trace metal diagenesis, via formation sulfides. The provides quantitative framework examining...
Environmental contextEpisodic extreme rainfall events may affect metal dynamics in rivers flowing within historical mining areas. This study provides an analysis of the water chemistry and geochemical processes associated with mobilisation metals during episodic events. Findings could be used to assess environmental quality streams draining spoil waste areas similar conditions, thereby guide future management strategies. AbstractThe increasing frequency magnitude by remobilisation deposition...
Using previously established procedures that utilise linear free energy relationships, we estimated binding constants for the Windermere Humic Aqueous Model VII (WHAM/Model VII) several radionuclide cations (Pd2+, Sn2+, U4+, NpO22+, Pu4+ and PuO22+). This extends number of can be calculated with model above 40 included in original work. When combined equilibrium inorganic species this allows calculation distributions chemical under a wide range conditions.
We developed a model that quantifies aquatic cationic toxicity by combination of the intrinsic toxicities metals and protons sensitivities test species. It is based on WHAM-FTOX model, which combines calculated binding cations organism with coefficients (αH, αM) to estimate variable FTOX, measure toxic effect; key parameter αM,max (applying at infinite time) depends upon both metal In our new WHAM-FTOXβ, values are given product αM* × β, where has single value for each metal, β To...