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Papers by Megan French

Frontiers in Marine Science

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.

Analytical Chemistry, Dec 1, 2004

BMC Public Health, Aug 22, 2019

Background: Choking is one of the leading causes of death among unintentional injuries in young c... more Background: Choking is one of the leading causes of death among unintentional injuries in young children. Food choking represents a considerable public health burden, which might be reduced through increased effective preventative education programs. We present a protocol for a community intervention trial termed CHOP (CHOking Prevention project) that aimed to teach Italian families how to prevent food choking injuries and increase knowledge relating to nutrition. Methods: Italian educational facilities were enrolled. Stratified randomization blocked by geographical area was performed. Each stratum was randomized to one of three different intervention strategies or to a control group. Educational intervention was delivered in the schools by experts and certified trainers as per the following three intervention strategies: directly to families (Strategy A); to teaching staff only, who subsequently delivered the same educational intervention to families (Strategy B); to health service staff only, who then delivered the educational intervention to teaching staff, who subsequently delivered the intervention to families (Strategy C). Participants completed a questionnaire about their knowledge on the topics presented during the educational interventions (pre-, post-, and follow-up of intervention). Information from the questionnaires was synthetized into 6 indicators in order to measure how effective each intervention strategy was. Discussion: The issue of food choking injuries in children is relevant to public health. The protocol we present provides an opportunity to progress towards overcoming such challenges through a working model that can be implemented also in other countries. Trial registration: ClinicalTrials.gov NCT03218618. The study was registered on 14 July 2017.

International Journal of Pediatric Otorhinolaryngology, Sep 1, 2019

This study aims to identify specific patterns of risk in order to contribute to the prevention of... more This study aims to identify specific patterns of risk in order to contribute to the prevention of Foreign Body (FB) injuries by assessing FB injury characteristics in Indian children. Methods: Single center case series are included in the worldwide registry on Foreign Bodies Injuries www. susysafe.org. Statistical analysis performed on FB injury data (age, medical information, FB anatomical location (ICD) and characteristics, and situational data) from 252 Indian children (0-14 years) was used to identify FB risk patterns. Results: The study included 252 FB injury cases, out of which 110 occurred in females (43.7%). Most of the reported FB injuries (N = 252) were located in the mouth, esophagus and stomach, or intestines and colon (34.5%), and in the nose (31.3%). The analysis of the median duration of all injuries (i.e., the difference between the reported injury time/date and the reported time/date of arrival at hospital) showed that children with a FB in the airways were those referred to the hospital latest (median of 332.50 min, p-value < 0.001). With regards to FB type, the majority of FB objects were non-food items and ingestion of coins accounted for 25% of all FB injuries. Conclusions: Cultural differences may exist with regards to the Indian diet being conducive to lower choking food risk for children, and to acceptability and accessibility to objects such as coins and stationery. Such findings should be taken into account when developing primary and secondary prevention strategies aimed at reducing the burden of such injuries in India.

Journal of Community Health, Apr 16, 2019

Choking injuries in children represent a severe public health burden. Although most choking injur... more Choking injuries in children represent a severe public health burden. Although most choking injuries are due to food, parents have often been found to be unaware of the choking hazards presented by food. In this context, healthcare professionals may play an important role in choking prevention by educating families. We investigate the perception of choking injury risk among healthcare profession students by comparing their awareness and knowledge of choking hazards with those of people without a specific health education. A survey was conducted among a sample of final year healthcare profession students from two universities in northern Italy and a sample of adults from the general population without any health education. Respondents were asked to look at ten pictures and identify the items that pose the greatest choking hazard to children of different age groups. Seventy-one students and 742 adults without any health education responded to the survey. A higher percentage of the adults without a health education identified a food item as posing the greatest choking hazard in comparison to the percentage of healthcare profession students. The results of this study suggest that there is a need to include specific educational modules on choking prevention in healthcare-related degree programs.

Deep-sea Research Part Ii-topical Studies in Oceanography, Jul 1, 2006

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.

Geophysical Research Letters, 2006

Simple leaching protocols have been used to examine trends in the solubility of aerosol nutrients... more Simple leaching protocols have been used to examine trends in the solubility of aerosol nutrients (Fe, P and Si) along a west-east transect through the Saharan dust plume (German SOLAS cruise M55) and between Saharan and southern hemisphere-origin aerosols. Solubilities were in the range 0.5-7.9% for Fe, 2.3-67% for P and 0.02-1.1% for Si, with lower values corresponding to samples of Saharan origin. Previous laboratory studies have suggested that aerosol Fe solubility might be enhanced by acid-and/or photo-chemistry during transport through the atmosphere, but only the solubility of P was observed to be higher at the western end of the transect than the eastern. This implies that if (photo)chemical processing of aerosol Fe occurs in the atmosphere, significant enhancement of Fe solubility requires longer than the 5-10 days associated with transport of Saharan dust across the tropical Atlantic Ocean.

Nutrients, 2020

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...

Deep Sea Research Part II: Topical Studies in Oceanography, 2007

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 fertilisation can alleviate HNLC conditions normally associated with the Southern Ocean. Therefore, during CROZEX, a large multidisciplinary study performed between November 2004 and January 2005, measurements of total dissolved iron (DFe, 0.2 m) were made on seawater from around the islands and atmospheric iron deposition estimated from rain and aerosol samples. DFe concentrations were determined by flow injection analysis with N,N-dimethyl-pphenylenediamine dihydrochloride (DPD) catalytic spectrophotometric detection. DFe concentrations varied between 0.086 nM and 2.48 nM, with low values in surface waters. Enrichment of dissolved iron (>1 nM) at close proximity to the islands suggests that the plateau and the associated sediments are a source of iron. Waters further 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-1 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 DFe 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.

Environmental management, Oct 8, 2017

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 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 0.07nMkmAˋ1atthetimeofsampling.UsinglateralandverticaldiffusioncoefficientsderivedfromRaisotopeprofilesandalsoestimatesofatmosphericinputs,itwasthenpossibletoestimateaDFeconcentrationof0.07 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 0.07nMkmAˋ1atthetimeofsampling.UsinglateralandverticaldiffusioncoefficientsderivedfromRaisotopeprofilesandalsoestimatesofatmosphericinputs,itwasthenpossibletoestimateaDFeconcentrationof0.55 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.

Journal of Hydrology, 2014

Arsenic Bolivian Altiplano Groundwater Poopó basin Surface water Trace elements s u m m a r y A g... more Arsenic Bolivian Altiplano Groundwater Poopó basin Surface water Trace elements s u m m a r y A geochemical approach was applied to understand the factors controlling the mobilization of As and trace elements (TEs) in mining areas of the Poopó and Antequera River sub-basins on the Bolivian Altiplano. A total of 52 samples (surface, groundwater and geothermal water) were collected during the rainy season (2009). Arsenic, Cd and Mn concentrations exceed World Health Organization (WHO) drinking water guidelines and Bolivian regulations for drinking water in 28 groundwater samples, but Cu, Ni, Pb and Zn do not. Arsenic, Cd, Mn, Pb and Zn concentrations exceed World Health Organization guidelines for drinking water and Bolivian regulations Class A standard for discharge to water bodies in 20 surface water samples, whereas levels of Cu do not, and Ni and Fe rarely exceed regulation and guideline values. Factor analysis was applied to 18 hydrochemical parameters of 52 samples. Five factors for groundwater (plagioclase weathering, dissolution of gypsum and halite, TEs mobilization at acidic pH, sulfide oxidation, and release of As) account for 86.5% of the total variance for Antequera and 83.9% for Poopó sub-basins. Four factors for surface water data (weathering and mobilization of TEs influenced by pH, dissolution of evaporate salts, neutralization of acid mine drainage, and As release due to dissolution of Mn and Fe oxides) account for 91% of the total variance in Antequera and 96% in Poopó sub-basins. The As and TEs mobilized in these regions could affect the local water sources, which is a prevalent concern with respect to water resource management in this semi-arid Altiplano region. Presence of both natural and anthropogenic sources of contamination requires careful monitoring of water quality.

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.

Analytical Chemistry, 2005

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.

Frontiers in Marine Science

Analytical Chemistry, Dec 1, 2004

BMC Public Health, Aug 22, 2019

International Journal of Pediatric Otorhinolaryngology, Sep 1, 2019

Journal of Community Health, Apr 16, 2019

Deep-sea Research Part Ii-topical Studies in Oceanography, Jul 1, 2006

Geophysical Research Letters, 2006

Nutrients, 2020

Deep Sea Research Part II: Topical Studies in Oceanography, 2007

Environmental management, Oct 8, 2017

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 0.07nMkmAˋ1atthetimeofsampling.UsinglateralandverticaldiffusioncoefficientsderivedfromRaisotopeprofilesandalsoestimatesofatmosphericinputs,itwasthenpossibletoestimateaDFeconcentrationof0.07 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 0.07nMkmAˋ1atthetimeofsampling.UsinglateralandverticaldiffusioncoefficientsderivedfromRaisotopeprofilesandalsoestimatesofatmosphericinputs,itwasthenpossibletoestimateaDFeconcentrationof0.55 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.

Journal of Hydrology, 2014

Deep Sea Research Part I: Oceanographic Research Papers, 2011

Analytical Chemistry, 2005