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Data supporting the article "Assessing the effectiveness of microplastic extraction methods on fishmeal with different properties ".
No full textThis dataset supports the publication:
"Assessing the effectiveness of microplastic extraction methods on fishmeal with different properties"
by C Way, M D. Hudson, I Williams, G. Langleyc, R Mars, Anal. Methods, 2022,14, 606-619 https://doi.org/10.1039/D1AY02154K
This data contains Excel data which are used for generating Tables for the article.
The data analyses Raw recovery rates of spiked microplastics from fishmeal. Data includes Total MPs spikes in specimen, Number of each polymer in a specimen,
and Recovery rate of individual polymers
Geographic location of data collection: University of Southampton, U.K.
Dataset available under a CC BY 4.0 licence
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Dataset in support of the article 'Evidence of underestimation in microplastic research: A meta-analysis of recovery rate studies'
No full textRaw Data of studies included in meta-analysis for the article 'Evidence of underestimation in microplastic research: A meta-analysis of recovery rate studies' published in Science of Total Environment</span
Challenges in optimising methods for extraction of microplastics from complex environmental matrices
No full textMicroplastics are a widespread contaminant of concern globally. Society, researchers and policy makers are interested in the quantities of microplastics present in the environment and the harm they pose to habitats, organisms and humans. Due to the rapid rise of research published finding microplastics in new complex environments, there has also been an increase in the development of complicated, multi-staged microplastic extraction methods. Successful and impactful results often rely on efficient and reliable methods. Researchers in this field face challenges when developing methods for these new, complex environments, such as standardisation, validation and producing accessible methods that consider monetary cost and environmental impact. Validation of methods is rarely undertaken, but when it is, it is achieved by performing a recovery rate study. These studies involve ‘spiking’ the environmental matrix with known amounts of microplastics, running the method and counting the recovered microplastics. To investigate published validation studies, a meta-analysis of 71 recovery rate studies, was carried out. Recovery rates were found to vary dependant on the environment studied, but were highest from plant material, whole organisms and excrement (>88% recovery). The average recovery rates provided an indication that microplastics in the environment could be underestimated by approximately 14% depending on the methods used. Methods were then replicated and developed to extract microplastics from fishmeal, which is a complex environmental medium found to contain microplastics. Fishmeal is a foodstuff that is of high importance for global food security and the microplastic contaminants have potential to enter food chains. Fishmeal properties were measured to investigate their influence on recovery of microplastics. An environmentally benign, generally safe and affordable method using calcium chloride, a dispersant and potassium hydroxide was found to produce the highest recovery rate (66.3%). Positive correlations were found between recovery rate and protein content of fishmeal, whereas negative correlations were found between recovery rate and organic content. To fully optimise methods for assessment of microplastics it is important to consider emerging analytical methods in the field and to test these with environmentally relevant material. The use of solvent extractions and thermal desorption GC-MS were investigated for their effectiveness at identifying chemical indicator markers of virgin microplastics, artificially weathered microplastics and naturally weathered microplastics. Chemical indicator markers were more commonly present in direct thermal desorption samples than the solvent extraction samples, and in some cases the most appropriate markers were present for weathered microplastics, but not for the virgin microplastics.The findings of this thesis highlight the importance of validating methods when trying to achieve standardisation, and the implications of underestimating true microplastic abundance due to low recovery rates. Development of affordable, safe and environmentally conscious methods is possible, however there may be a trade-off between this and effectiveness of the method. Moreover, this thesis has demonstrated how the recovery of microplastics can vary dependant on environmental and microplastic properties. Thus microplastics should not be considered a single contaminant, but more like a mixture of chemicals and additives with different histories in various matrices. With the prospect of standardised, validated, affordable, safe, environmentally benign and realistic methods, research in this field would become more accessible to many people worldwide, which is needed when studying such a ubiquitous group of pollutants
Hundreds of millions of microplastic particles could be flowing into UK rivers, hidden in raw sewage
No full textMicroplastics are everywhere. Snow close to the peak of Mount Everest was found to contain on average 30 microplastic particles per litre. And 11,000m below sea level, in the Pacific Ocean’s Mariana Trench, an average of 2,200 microplastic particles per litre of sediment were found.Microplastics are bits of plastic smaller than 5mm in diameter. They come from a range of sources including toiletries, cosmetics, fibres from washing our clothes, plus a range of other routes, such as road paints, tyre wear and fragments of litter. Scientific reports are showing astounding amounts of these plastics globally, including in remote areas, but those numbers have been significantly underestimated.Recently, there was public anger over revelations that Thames Water, a UK utilities company, released 2 billion litres of raw sewage into the River Thames in just two days. This is on the back of Southern Water’s record £90 million fine for thousands of illegal raw sewage discharges over several years. However, these stories do not report on the amount of microplastics that would have also been released within these discharges as that data is not routinely collected.Applying an example of the average numbers of microplastics found in a litre of effluent to the amount released in the Thames case could equate to about 500 million microplastic particles entering the River Thames. This is happening all over the UK, with raw sewage being deposited along many British coastlines and rivers
Evidence of underestimation in microplastic research: A meta-analysis of recovery rate studies
No full textResearch on microplastics in the environment is of high interest to many scientists and industries globally. Key to the success of this research is the accuracy, efficiency, reliability, robustness and repeatability of the method (s) used to isolate the microplastics from environmental media. However, with microplastics now being found in new complex media, many multifaceted methods have been developed to research the quantities of these pollutants. To validate new methods, recovery studies can be undertaken by spiking the test medium with known quantities of plastics. The method is typically run as normal, and the recovered plastics counted to give a recovery rate. A current issue in this field is that methods are rarely or poorly validated in this way. Here, we conducted a meta-analysis on 71 recovery rate studies. We found sediment was the most studied medium and saline solutions were the most used reagents. Polyethylene and polystyrene were the most used spiking polymers, which is relevant to the most common polymers in the environment. We found that recovery rates were highest from plant material, whole organisms and excrement (>88%), and lowest from fishmeal, water and soil (58–71%). Moreover, all reagents but water were able to recover more than 80% of the spiked plastics. We believe we are the first (to our knowledge) to provide an overarching indication for the underestimation of microplastics in the environment of approximately 14% across the studies we reviewed, varying with the methods used. Furthermore, we recommend that the quality, use and reporting of recovery rate studies should be improved to aid the standardisation and replication of microplastic research
Assessing the effectiveness of microplastic extraction methods on fishmeal with different properties
No full textMicroplastic presence in fishmeal is an emerging research area because of its potential to enter food chains, and the importance of fishmeal within global food security. However, fishmeal is a complex medium dependant on fish composition. This study measured properties (organics, carbonates, protein and density) of five fishmeal types (trimmings, sardine and anchovy, krill, tuna and salmon), sourced from locations worldwide (Norway, South America, Antarctica, Spain and Scotland). Microplastic recovery rates were compared for existing methodologies using sodium chloride overflows and potassium hydroxide digestions and then compared to newly developed methods. These methods included dispersants and calcium chloride density separations which were developed and designed to be environmentally conscious and affordable, which we argue should become an international standard approach for researchers. A calcium chloride overflow with dispersant and potassium hydroxide digestion provided the highest recovery rate in sardine and anchovy fishmeal (66.3%). Positive correlations with recovery rate were found with protein content, and negative correlations with organic content. Low recovery rates found here suggest microplastics in fishmeal reported in the literature are underestimated. With complex media such as fishmeal, attention must be paid to variation between types and composition when choosing methods and interpreting results
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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