IntroductionAccording to the Marine Strategy Framework Directive (MSFD, 2008/56/EC), member state... more IntroductionAccording to the Marine Strategy Framework Directive (MSFD, 2008/56/EC), member states of the European Union (EU) had to develop a common approach in environmental monitoring and assessment. Regarding marine pollution assessments, large heterogeneities remain regarding sampling protocols, analytical methods, and quality assurance (QA) and quality control (QC) procedures. Further, data availability for Descriptor 8 (contaminants) was very fragmented in the first cycle of the MSFD. As one of the major EU spatial data infrastructures for providing access to marine data, EMODnet Chemistry has endeavoured to overcome data fragmentation and increase data ‘FAIRness’ (findable, accessible, interoperable, and reusable).MethodsAiming to improve the reliability of marine contaminant data for assessment purposes under the MSFD, detailed QA/QC information was collected using a questionnaire based on the requirements of the European Environment Agency, International Council for the Ex...
Diatoms are key primary producers and therefore make an important contribution to carbon export. ... more Diatoms are key primary producers and therefore make an important contribution to carbon export. These phytoplankton utilise dissolved silica (DSi), sourced from riverine, atmospheric, sedimentary and hydrothermal inputs, and convert it to biogenic silica (bSiO2). Some of this bSiO2 dissolves in the water column, regenerating the DSi pool, whereas the remaining fraction settles out to the sediments (e.g. via aggregates) to form bSiO2 accumulations. These occur primarily in the Southern Ocean and provide a sedimentary archive regarding export production over hundreds to millions of years. Although atmospheric inputs of soluble Si to the surface ocean contribute to nutrient DSi, findings in this thesis reveal that they represent just ~0.2 – 0.4% of total DSi inputs to the Global Ocean. It is also shown that aerosol Si inputs originate primarily from Saharan dust, but that the soluble fraction is small (0.12% - 0.29%) in comparison to total aerosol Si. These solubilities are an order of magnitude lower than that used in an existing hypothesis that proposed a global dust increase of 2 – 8 times present values could explain glacial - interglacial pCO2 transitions. Hence, it is shown that supply would actually need to increase by a factor of 50 – 300 for this hypothesis to hold. Data obtained during the CROZEX cruise showed that DSi supports high diatom productivity to the north of the Crozet islands in the Southern Ocean, where iron inputs from underlying sediments/plateau relieves High Nutrient Low Chlorophyll (HNLC) conditions. Results presented in this thesis show that a phytoplankton bloom in October 2004 was characterised by large, heavily silicified diatoms. As nutrients were depleted there was a shift towards smaller and more lightly silicified cells that dissolved within the euphotic zone. In contrast, more silicified cells tended to be exported, often as aggregated bSiO2, particularly to the south of the plateau where Fe limitation meant that low productivity was characterised by heavily silicified diatoms typical of HNLC conditions. The importance of aggregation, diatom species, physiological state and temperature in bSiO2 dissolution was investigated experimentally. Findings presented in this thesis revealed that i) the rate of dissolution of aggregates formed using the highly silicified, typically HNLC diatom Fragilariopsis kerguelensis was significantly lower than that for the lesser silicified Chaetoceros debilis, ii) dissolution increased markedly with temperature, and iii) dissolution of exponentially grown C.debilis aggregates began with ~14 day lag in comparison to their senescent counterparts.
Nutrition is emerging as a key factor in promoting healthy lifestyles in the growing elderly popu... more Nutrition is emerging as a key factor in promoting healthy lifestyles in the growing elderly population across Europe. In this study, we examined the non-animal-derived food source consumption among the elderly European population to evaluate the actual contributions of these foods to the diet of the elders. We gathered 21 studies conducted in 17 European countries to evaluate the fruit, vegetable, and legume (along with their derived products) consumption among the elderly (>65 years) population. Foods’ nutritional values were calculated and compared to the recommended intakes. A Bayesian multilevel hierarchical analysis was conducted to estimate the caloric intake of food categories and to compare the elderly and general adult populations. Although the lowest consumption was generally associated with the lowest nutrient and fiber intake, the reverse was not always the case. Concerning the general adult population, no differences in the related caloric intake of elders were noti...
Assessing water sources for drinking and irrigation along with community vulnerability, especiall... more Assessing water sources for drinking and irrigation along with community vulnerability, especially in developing and rural regions, is important for reducing risk posed by poor water quality and limited water availability and accessibility. We present a case study of rural mining-agricultural communities in the Lake Poopó Basin, one of the poorest regions on the Bolivian Altiplano. Here, relatively low rainfall, high evaporation, salinization and unregulated mining activity have contributed to environmental degradation and water issues, which is a situation facing many Altiplano communities. Social data from 72 households and chemical water quality data from 27 surface water and groundwater sites obtained between August 2013 and July 2014 were used to develop locally relevant vulnerability assessment methodologies and ratings with respect to water availability and quality, and Chemical Water Quality Hazard Ratings to assess water quality status. Levels of natural and mining-related ...
Assessing water sources for drinking and irrigation along with community vulnerability, especiall... more Assessing water sources for drinking and irrigation along with community vulnerability, especially in developing and rural regions, is important for reducing risk posed by poor water quality and limited water availability and accessibility. We present a case study of rural mining-agricultural communities in the Lake Poopó Basin, one of the poorest regions on the Bolivian Altiplano. Here, relatively low rainfall, high evaporation, salinization and unregulated mining activity have contributed to environmental degradation and water issues, which is a situation facing many Altiplano communities. Social data from 72 households and chemical water quality data from 27 surface water and groundwater sites obtained between August 2013 and July 2014 were used to develop locally relevant vulnerability assessment methodologies and ratings with respect to water availability and quality, and Chemical Water Quality Hazard Ratings to assess water quality status. Levels of natural and mining-related contamination in many waters (CWQHR ≥ 6; 78% of assessed sites) mean that effective remediation would be challenging and require substantial investment. Although waters of fair to good chemical quality (CWQHR ≤ 5; 22% of assessed sites) do exist, treatment may still be required depending on use, and access issues remain problematic. There is a need to comply with water quality legislation, improve and maintain basic water supply and storage infrastructure, build and operate water and wastewater treatment plants, and adequately and safely contain and treat mine waste. This study serves as a framework that could be used elsewhere for assessing and mitigating water contamination and availability affecting vulnerable populations.
The atmosphere can be an important source of nutrients to remote ocean waters, e.g., in supplying... more The atmosphere can be an important source of nutrients to remote ocean waters, e.g., in supplying iron to nitrogen fixers in the tropical North Atlantic. We use results obtained from aerosol collection during four meridional transect cruises of the Atlantic Ocean in an attempt to identify sources of soluble nutrient species (Fe, N, P and Si) to the Atlantic atmosphere. The Sahara desert was the dominant source of soluble aerosol Fe and Si and also a significant source of aerosol P. Biomass burning and another source, possibly primary particles derived from vegetation, also contribute to the aerosol P loading. Industrial (NO x) and agricultural (ammonium) sources contribute to high nitrogen concentrations in the northern hemisphere, while biomass burning appears to be a significant seasonal source of N to the southern hemisphere. This work is an initial step in our aim to describe the atmospheric nutrient inputs to the Atlantic basin using a much larger set of aerosol and rain samples that will be obtained during the Atlantic Meridional Transect (AMT) project and other field campaigns.
The annual phytoplankton bloom occurring north of the Crozet Plateau provides a rare opportunity ... more The annual phytoplankton bloom occurring north of the Crozet Plateau provides a rare opportunity to examine the hypothesis that natural iron fertilization can alleviate high-nutrient low-chlorophyll (HNLC) conditions normally associated with the Southern Ocean. Therefore, during CROZet natural iron bloom and EXport experiment (CROZEX), a large multidisciplinary study performed between November 2004 and January 2005, measurements of total dissolved iron (D Fe p0.2 mm) were made on seawater from around the islands and atmospheric iron deposition estimated from rain and aerosol samples. D Fe concentrations were determined by flow injection analysis with N,N-dimethyl-p-phenylenediamine dihydrochloride (DPD) catalytic spectrophotometric detection. D Fe concentrations varied between 0.086 and 2.48 nM, with low values in surface waters. Enrichment of dissolved iron (41 nM) at close proximity to the islands suggests that the plateau and the associated sediments are a source of iron. Waters farther north also appear to be affected by this input of coastal and shelf origin, although dissolved iron concentrations decrease as a function of distance to the north of the plateau with a gradient of $0.07 nM km À1 at the time of sampling. Using lateral and vertical diffusion coefficients derived from Ra isotope profiles and also estimates of atmospheric inputs, it was then possible to estimate a D Fe concentration of $0.55 nM to the north of the islands prior to the bloom event, which is sufficient to initiate the bloom, the lateral island source being the largest component. A similar situation is observed for other Sub-Antarctic Islands such as Kerguelen, South Georgia, that supply dissolved iron to their surrounding waters, thus enhancing chlorophyll concentrations.
Deep Sea Research Part I: Oceanographic Research Papers, 2011
ABSTRACT The majority of opal produced by diatoms dissolves during their sedimentation to the sea... more ABSTRACT The majority of opal produced by diatoms dissolves during their sedimentation to the seafloor, but spatial and temporal variability of dissolution rates are large. Controlled laboratory experiments using live phytoplankton or phyto-detritus may help identify the different processes, including those that are biologically mediated or physico-chemically driven, that impact the dissolution of frustules and the aforementioned variability. Results of eight bSiO2 dissolution experiments, seven of which were conducted at low temperatures (<6 °C) are presented within the context of earlier similar studies, and different phases of dissolution dynamics characterized. TEP concentration, aggregation and the physiological status of the diatoms determined the period during which diatoms may maintain the protective membrane that surrounds their frustule and effectively reduces or completely inhibits (lag period) dissolution for some time. Once diatoms loose the capability to maintain their protective membrane, bacterial activity compromises it. Physico-chemical dissolution, which depends on frustule structure and abiotic environmental conditions, begins once the protective membrane is damaged. The ability of diatoms to maintain their membrane, the bacterial composition and activity governing its degradation, and the physico-chemical dissolution dynamics of exposed frustules are all impacted by temperature. In our experiments instantaneous dissolution rates were not dependant on bSiO2 concentration at low temperatures, although such a relationship was observed under otherwise identical conditions at 15 °C, implying that biotic factors rather than physico-chemical processes initially dominated dissolution at polar temperatures. Since inhibition of bSiO2 dissolution at low temperatures was inhibited to a greater extent than organic matter degradation, we postulate that it was not reduced bacterial activity but the enhanced ability of diatoms to maintain their membrane and thus withstand microbial attack that caused the low initial dissolution rates at <6 °C. In situ, interactions between the different biotic and abiotic processes impacting dissolution combined with differences in sinking velocity of diatom aggregates and grazing effects could easily explain high spatial and temporal variability in the accumulation of diatoms on the seafloor. Simple calculations based on our experimental results suggest that Fragilariopsis kerguelensis, for example, would be appreciably more likely to reach the seafloor than Chaetoceros debilis if both grow at low growth rates, e.g. under growth limiting conditions. However, dissolution behavior of Chaetoceros debilis during sedimentation may differ under conditions where this species forms large blooms.Highlights► Initially, biology controls dissolution of diatom frustules during sedimentation. ► Ability of diatoms to maintain their protective membrane postpones onset of dissolution. ► Aggregation/TEP and life history impact this ability. ► Physico-chemical dissolution begins after bacterial activity compromised the protective layer. ► Temperature affects all three processes: diatom viability, bacterial activity, and physico-chemical dissolution.
A novel technique for obtaining time-integrated 99Tc concentrations in seawater has been develope... more A novel technique for obtaining time-integrated 99Tc concentrations in seawater has been developed, using diffusive gradients in thin films (DGT). The performance of TEVA resin as a binding agent for 99Tc was investigated via laboratory experiments. The accumulated 99Tc activity per unit area of resin-gel was proportional to both the bulk solution activity and the exposure time for deployments of up to 2 weeks. The response of DGT was found to be independent of solution chemistries over the pH range 3-8 and ionic strength range 0.01-1.3 M. Seawater has pH 8 and ionic strength of approximately 0.7 M; therefore, the potential of the technique for field deployment in seawater was demonstrated. Detection limits of 0.05 and 0.025 Bq L(-1), for 2- and 4-week DGT deployments, respectively, were calculated for 99Tc measurement by liquid scintillation spectrometry. Using quadrupole ICPMS to measure bound 99Tc could reduce these detection limits to 0.125 mBq L(-1) for a 4-week deployment. These detection limits are sufficiently low for monitoring contaminated environments, including the Irish Sea. This method is simpler and faster than other 99Tc analysis methods and represents the only means of obtaining time-integrated data.
IntroductionAccording to the Marine Strategy Framework Directive (MSFD, 2008/56/EC), member state... more IntroductionAccording to the Marine Strategy Framework Directive (MSFD, 2008/56/EC), member states of the European Union (EU) had to develop a common approach in environmental monitoring and assessment. Regarding marine pollution assessments, large heterogeneities remain regarding sampling protocols, analytical methods, and quality assurance (QA) and quality control (QC) procedures. Further, data availability for Descriptor 8 (contaminants) was very fragmented in the first cycle of the MSFD. As one of the major EU spatial data infrastructures for providing access to marine data, EMODnet Chemistry has endeavoured to overcome data fragmentation and increase data ‘FAIRness’ (findable, accessible, interoperable, and reusable).MethodsAiming to improve the reliability of marine contaminant data for assessment purposes under the MSFD, detailed QA/QC information was collected using a questionnaire based on the requirements of the European Environment Agency, International Council for the Ex...
Diatoms are key primary producers and therefore make an important contribution to carbon export. ... more Diatoms are key primary producers and therefore make an important contribution to carbon export. These phytoplankton utilise dissolved silica (DSi), sourced from riverine, atmospheric, sedimentary and hydrothermal inputs, and convert it to biogenic silica (bSiO2). Some of this bSiO2 dissolves in the water column, regenerating the DSi pool, whereas the remaining fraction settles out to the sediments (e.g. via aggregates) to form bSiO2 accumulations. These occur primarily in the Southern Ocean and provide a sedimentary archive regarding export production over hundreds to millions of years. Although atmospheric inputs of soluble Si to the surface ocean contribute to nutrient DSi, findings in this thesis reveal that they represent just ~0.2 – 0.4% of total DSi inputs to the Global Ocean. It is also shown that aerosol Si inputs originate primarily from Saharan dust, but that the soluble fraction is small (0.12% - 0.29%) in comparison to total aerosol Si. These solubilities are an order of magnitude lower than that used in an existing hypothesis that proposed a global dust increase of 2 – 8 times present values could explain glacial - interglacial pCO2 transitions. Hence, it is shown that supply would actually need to increase by a factor of 50 – 300 for this hypothesis to hold. Data obtained during the CROZEX cruise showed that DSi supports high diatom productivity to the north of the Crozet islands in the Southern Ocean, where iron inputs from underlying sediments/plateau relieves High Nutrient Low Chlorophyll (HNLC) conditions. Results presented in this thesis show that a phytoplankton bloom in October 2004 was characterised by large, heavily silicified diatoms. As nutrients were depleted there was a shift towards smaller and more lightly silicified cells that dissolved within the euphotic zone. In contrast, more silicified cells tended to be exported, often as aggregated bSiO2, particularly to the south of the plateau where Fe limitation meant that low productivity was characterised by heavily silicified diatoms typical of HNLC conditions. The importance of aggregation, diatom species, physiological state and temperature in bSiO2 dissolution was investigated experimentally. Findings presented in this thesis revealed that i) the rate of dissolution of aggregates formed using the highly silicified, typically HNLC diatom Fragilariopsis kerguelensis was significantly lower than that for the lesser silicified Chaetoceros debilis, ii) dissolution increased markedly with temperature, and iii) dissolution of exponentially grown C.debilis aggregates began with ~14 day lag in comparison to their senescent counterparts.
Nutrition is emerging as a key factor in promoting healthy lifestyles in the growing elderly popu... more Nutrition is emerging as a key factor in promoting healthy lifestyles in the growing elderly population across Europe. In this study, we examined the non-animal-derived food source consumption among the elderly European population to evaluate the actual contributions of these foods to the diet of the elders. We gathered 21 studies conducted in 17 European countries to evaluate the fruit, vegetable, and legume (along with their derived products) consumption among the elderly (>65 years) population. Foods’ nutritional values were calculated and compared to the recommended intakes. A Bayesian multilevel hierarchical analysis was conducted to estimate the caloric intake of food categories and to compare the elderly and general adult populations. Although the lowest consumption was generally associated with the lowest nutrient and fiber intake, the reverse was not always the case. Concerning the general adult population, no differences in the related caloric intake of elders were noti...
Assessing water sources for drinking and irrigation along with community vulnerability, especiall... more Assessing water sources for drinking and irrigation along with community vulnerability, especially in developing and rural regions, is important for reducing risk posed by poor water quality and limited water availability and accessibility. We present a case study of rural mining-agricultural communities in the Lake Poopó Basin, one of the poorest regions on the Bolivian Altiplano. Here, relatively low rainfall, high evaporation, salinization and unregulated mining activity have contributed to environmental degradation and water issues, which is a situation facing many Altiplano communities. Social data from 72 households and chemical water quality data from 27 surface water and groundwater sites obtained between August 2013 and July 2014 were used to develop locally relevant vulnerability assessment methodologies and ratings with respect to water availability and quality, and Chemical Water Quality Hazard Ratings to assess water quality status. Levels of natural and mining-related ...
Assessing water sources for drinking and irrigation along with community vulnerability, especiall... more Assessing water sources for drinking and irrigation along with community vulnerability, especially in developing and rural regions, is important for reducing risk posed by poor water quality and limited water availability and accessibility. We present a case study of rural mining-agricultural communities in the Lake Poopó Basin, one of the poorest regions on the Bolivian Altiplano. Here, relatively low rainfall, high evaporation, salinization and unregulated mining activity have contributed to environmental degradation and water issues, which is a situation facing many Altiplano communities. Social data from 72 households and chemical water quality data from 27 surface water and groundwater sites obtained between August 2013 and July 2014 were used to develop locally relevant vulnerability assessment methodologies and ratings with respect to water availability and quality, and Chemical Water Quality Hazard Ratings to assess water quality status. Levels of natural and mining-related contamination in many waters (CWQHR ≥ 6; 78% of assessed sites) mean that effective remediation would be challenging and require substantial investment. Although waters of fair to good chemical quality (CWQHR ≤ 5; 22% of assessed sites) do exist, treatment may still be required depending on use, and access issues remain problematic. There is a need to comply with water quality legislation, improve and maintain basic water supply and storage infrastructure, build and operate water and wastewater treatment plants, and adequately and safely contain and treat mine waste. This study serves as a framework that could be used elsewhere for assessing and mitigating water contamination and availability affecting vulnerable populations.
The atmosphere can be an important source of nutrients to remote ocean waters, e.g., in supplying... more The atmosphere can be an important source of nutrients to remote ocean waters, e.g., in supplying iron to nitrogen fixers in the tropical North Atlantic. We use results obtained from aerosol collection during four meridional transect cruises of the Atlantic Ocean in an attempt to identify sources of soluble nutrient species (Fe, N, P and Si) to the Atlantic atmosphere. The Sahara desert was the dominant source of soluble aerosol Fe and Si and also a significant source of aerosol P. Biomass burning and another source, possibly primary particles derived from vegetation, also contribute to the aerosol P loading. Industrial (NO x) and agricultural (ammonium) sources contribute to high nitrogen concentrations in the northern hemisphere, while biomass burning appears to be a significant seasonal source of N to the southern hemisphere. This work is an initial step in our aim to describe the atmospheric nutrient inputs to the Atlantic basin using a much larger set of aerosol and rain samples that will be obtained during the Atlantic Meridional Transect (AMT) project and other field campaigns.
The annual phytoplankton bloom occurring north of the Crozet Plateau provides a rare opportunity ... more The annual phytoplankton bloom occurring north of the Crozet Plateau provides a rare opportunity to examine the hypothesis that natural iron fertilization can alleviate high-nutrient low-chlorophyll (HNLC) conditions normally associated with the Southern Ocean. Therefore, during CROZet natural iron bloom and EXport experiment (CROZEX), a large multidisciplinary study performed between November 2004 and January 2005, measurements of total dissolved iron (D Fe p0.2 mm) were made on seawater from around the islands and atmospheric iron deposition estimated from rain and aerosol samples. D Fe concentrations were determined by flow injection analysis with N,N-dimethyl-p-phenylenediamine dihydrochloride (DPD) catalytic spectrophotometric detection. D Fe concentrations varied between 0.086 and 2.48 nM, with low values in surface waters. Enrichment of dissolved iron (41 nM) at close proximity to the islands suggests that the plateau and the associated sediments are a source of iron. Waters farther north also appear to be affected by this input of coastal and shelf origin, although dissolved iron concentrations decrease as a function of distance to the north of the plateau with a gradient of $0.07 nM km À1 at the time of sampling. Using lateral and vertical diffusion coefficients derived from Ra isotope profiles and also estimates of atmospheric inputs, it was then possible to estimate a D Fe concentration of $0.55 nM to the north of the islands prior to the bloom event, which is sufficient to initiate the bloom, the lateral island source being the largest component. A similar situation is observed for other Sub-Antarctic Islands such as Kerguelen, South Georgia, that supply dissolved iron to their surrounding waters, thus enhancing chlorophyll concentrations.
Deep Sea Research Part I: Oceanographic Research Papers, 2011
ABSTRACT The majority of opal produced by diatoms dissolves during their sedimentation to the sea... more ABSTRACT The majority of opal produced by diatoms dissolves during their sedimentation to the seafloor, but spatial and temporal variability of dissolution rates are large. Controlled laboratory experiments using live phytoplankton or phyto-detritus may help identify the different processes, including those that are biologically mediated or physico-chemically driven, that impact the dissolution of frustules and the aforementioned variability. Results of eight bSiO2 dissolution experiments, seven of which were conducted at low temperatures (<6 °C) are presented within the context of earlier similar studies, and different phases of dissolution dynamics characterized. TEP concentration, aggregation and the physiological status of the diatoms determined the period during which diatoms may maintain the protective membrane that surrounds their frustule and effectively reduces or completely inhibits (lag period) dissolution for some time. Once diatoms loose the capability to maintain their protective membrane, bacterial activity compromises it. Physico-chemical dissolution, which depends on frustule structure and abiotic environmental conditions, begins once the protective membrane is damaged. The ability of diatoms to maintain their membrane, the bacterial composition and activity governing its degradation, and the physico-chemical dissolution dynamics of exposed frustules are all impacted by temperature. In our experiments instantaneous dissolution rates were not dependant on bSiO2 concentration at low temperatures, although such a relationship was observed under otherwise identical conditions at 15 °C, implying that biotic factors rather than physico-chemical processes initially dominated dissolution at polar temperatures. Since inhibition of bSiO2 dissolution at low temperatures was inhibited to a greater extent than organic matter degradation, we postulate that it was not reduced bacterial activity but the enhanced ability of diatoms to maintain their membrane and thus withstand microbial attack that caused the low initial dissolution rates at <6 °C. In situ, interactions between the different biotic and abiotic processes impacting dissolution combined with differences in sinking velocity of diatom aggregates and grazing effects could easily explain high spatial and temporal variability in the accumulation of diatoms on the seafloor. Simple calculations based on our experimental results suggest that Fragilariopsis kerguelensis, for example, would be appreciably more likely to reach the seafloor than Chaetoceros debilis if both grow at low growth rates, e.g. under growth limiting conditions. However, dissolution behavior of Chaetoceros debilis during sedimentation may differ under conditions where this species forms large blooms.Highlights► Initially, biology controls dissolution of diatom frustules during sedimentation. ► Ability of diatoms to maintain their protective membrane postpones onset of dissolution. ► Aggregation/TEP and life history impact this ability. ► Physico-chemical dissolution begins after bacterial activity compromised the protective layer. ► Temperature affects all three processes: diatom viability, bacterial activity, and physico-chemical dissolution.
A novel technique for obtaining time-integrated 99Tc concentrations in seawater has been develope... more A novel technique for obtaining time-integrated 99Tc concentrations in seawater has been developed, using diffusive gradients in thin films (DGT). The performance of TEVA resin as a binding agent for 99Tc was investigated via laboratory experiments. The accumulated 99Tc activity per unit area of resin-gel was proportional to both the bulk solution activity and the exposure time for deployments of up to 2 weeks. The response of DGT was found to be independent of solution chemistries over the pH range 3-8 and ionic strength range 0.01-1.3 M. Seawater has pH 8 and ionic strength of approximately 0.7 M; therefore, the potential of the technique for field deployment in seawater was demonstrated. Detection limits of 0.05 and 0.025 Bq L(-1), for 2- and 4-week DGT deployments, respectively, were calculated for 99Tc measurement by liquid scintillation spectrometry. Using quadrupole ICPMS to measure bound 99Tc could reduce these detection limits to 0.125 mBq L(-1) for a 4-week deployment. These detection limits are sufficiently low for monitoring contaminated environments, including the Irish Sea. This method is simpler and faster than other 99Tc analysis methods and represents the only means of obtaining time-integrated data.
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