Short-term arsenic exposure reduces diatom cell size in biofilm communities
Author(s)Barral Fraga, Laura
Urrea Clos, Gemma
Guasch i Padró, Helena
Arsènic -- Toxicologia
Arsenic -- Toxicology
Arsènic -- Aspectes ambientals
Arsenic -- Environmental aspects
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AbstractArsenic (As) pollution in water has important impacts for human and ecosystem health. In freshwaters, arsenate (AsV) can be taken up by microalgae due to its similarity with phosphate molecules, its toxicity being aggravated under phosphate depletion. An experiment combining ecological and ecotoxicological descriptors was conducted to investigate the effects of AsV (130 μg L−1 over 13 days) on the structure and function of fluvial biofilm under phosphate-limiting conditions. We further incorporated fish (Gambusia holbrooki) into our experimental system, expecting fish to provide more available phosphate for algae and, consequently, protecting algae against As toxicity. However, this protection role was not fully achieved. Arsenic inhibited algal growth and productivity but not bacteria. The diatom community was clearly affected showing a strong reduction in cell biovolume; selection for tolerant species, in particular Achnanthidium minutissimum; and a reduction in species richness. Our results have important implications for risk assessment, as the experimental As concentration used was lower than acute toxicity criteria established by the USEPA
Financial support was provided by Spanish Science and Education Ministry (project CTM2009-14111-CO2-01), Spanish Economy and Competitiveness Ministry (project CGL2013-43822-R), and the University of Girona project SING12/09
0944-1344 (versió paper)
1614-7499 (versió electrònica)
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Effects of low arsenic concentration exposure on freshwater fish in the presence of fluvial biofilmsTuulaikhuu, Baigal Amar; Bonet, Berta; Guasch, Helena (Elsevier, 2016-02-15)Arsenic (As) is a highly toxic element and its carcinogenic effect on living organisms is well known. However, predicting real effects in the environment requires an ecological approach since toxicity is influenced by many environmental and biological factors. The purpose of this paper was to evaluate if environmentally-realistic arsenic exposure causes toxicity to fish. An experiment with four different treatments (control (C), biofilm (B), arsenic (+ As) and biofilm with arsenic (B + As)) was conducted and each one included sediment to enhance environmental realism, allowing the testing of the interactive effects of biofilm and arsenic on the toxicity to fish. Average arsenic exposure to Eastern mosquitofish (Gambusia holbrooki) was 40.5. ±. 7.5 μg/L for + As treatment and 34.4. ±. 1.4. μg/L for B + As treatment for 56 days. Fish were affected directly and indirectly by this low arsenic concentration since exposure did not only affect fish but also the function of periphytic biofilms. Arsenic effects on the superoxide dismutase (SOD) and glutathione reductase (GR) activities in the liver of mosquitofish were ameliorated in the presence of biofilms at the beginning of exposure (day 9). Moreover, fish weight gaining was only affected in the treatment without biofilm. After longer exposure (56 days), effects of exposure were clearly seen. Fish showed a marked increase in the catalase (CAT) activity in the liver but the interactive influence of biofilms was not further observed since the arsenic-affected biofilm had lost its role in water purification. Our results highlight the interest and application of incorporating some of the complexity of natural systems in ecotoxicology and support the use of criterion continuous concentration (CCC) for arsenic lower than 150. μg/L and closer to the water quality criteria to protect aquatic life recommended by the Canadian government which is 5. μg As/L
Visual analytics of arsenic in various foodsYedjou, C.; Awofolu, Omotayo Rafiu; Moja, S. J.; Johnson, Matilda Olubunmi (2014-11-18)Arsenic is a naturally occurring toxic metal and its presence in food composites could be a potential risk to the health of both humans and animals. Arseniccontaminated groundwater is often used for food and animal consumption, irrigation of soils, which could potentially lead to arsenic entering the human food chain. Its side effects include multiple organ damage, cancers, heart disease, diabetes mellitus, hypertension, lung disease and peripheral vascular disease. Research investigations, epidemiologic surveys and total diet studies (market baskets) provide datasets, information and knowledge on arsenic content in foods. The determination of the concentration of arsenic in rice varieties is an active area of research. With the increasing capability to measure the concentration of arsenic in foods, there are volumes of varied and continuously generated datasets on arsenic in food groups.
Visual analytics, which integrates techniques from information visualization and computational data analysis via interactive visual interfaces, presents an approach to enable data on arsenic concentrations to be visually represented.
The goal of this doctoral research in Environmental Science is to address the need to provide visual analytical decision support tools on arsenic content in various foods with special emphasis on rice. The hypothesis of this doctoral thesis research is that software enabled visual representation and user interaction facilitated by visual
interfaces will help discover hidden relationships between arsenic content and food categories.
The specific objectives investigated were: (1) Provide insightful visual analytic views of compiled data on arsenic in food categories; (2) Categorize table ready foods by arsenic content; (3) Compare arsenic content in rice product categories and (4) Identify informative sentences on arsenic concentrations in rice. The overall research method is secondary data analyses using visual analytics techniques implemented through Tableau Software.
Several datasets were utilized to conduct visual analytical representations of data on arsenic concentrations in foods. These consisted of (i) arsenic concentrations in 459 crop samples; (ii) arsenic concentrations in 328 table ready foods from multi-year total diet studies; (iii) estimates of daily inorganic arsenic intake for 49 food groups from multicountry total diet studies; (iv) arsenic content in rice product categories for 193 samples of rice and rice products; (v) 758 sentences extracted from PubMed abstracts on arsenic in rice.
Several key insights were made in this doctoral research. The concentration of inorganic arsenic in instant rice was lower than those of other rice types. The concentration of Dimethylarsinic Acid (DMA) in wild rice, an aquatic grass, was notably lower than rice varieties (e.g. 0.0099 ppm versus 0.182 for a long grain white rice). The categorization of 328 table ready foods into 12 categories enhances the communication on arsenic concentrations. Outlier concentration of arsenic in rice were observed in views constructed for integrating data from four total diet studies. The 193 rice samples were grouped into two groups using a cut-off level of 3 mcg of inorganic arsenic per
serving. The visual analytics views constructed allow users to specify cut-off levels desired. A total of 86 sentences from 53 PubMed abstracts were identified as informative for arsenic concentrations. The sentences enabled literature curation for arsenic concentration and additional supporting information such as location of the research. An
informative sentence provided global “normal” range of 0.08 to 0.20 mg/kg for arsenic in rice. A visual analytics resource developed was a dashboard that facilitates the interaction with text and a connection to the knowledge base of the PubMed literature database.
The research reported provides a foundation for additional investigations on visual analytics of data on arsenic concentrations in foods. Considering the massive and complex data associated with contaminants in foods, the development of visual analytics tools are needed to facilitate diverse human cognitive tasks. Visual analytics
tools can provide integrated automated analysis; interaction with data; and data visualization critically needed to enhance decision making. Stakeholders that would benefit include consumers; food and health safety personnel; farmers; and food producers. Arsenic content of baby foods warrants attention because of the early life exposures that could have life time adverse health consequences.
The action of microorganisms in the soil is associated with availability of arsenic species for uptake by plants. Genomic data on microbial communities presents wealth of data to identify mitigation strategies for arsenic uptake by plants. Arsenic metabolism pathways encoded in microbial genomes warrants further research. Visual analytics tasks could facilitate the discovery of biological processes for mitigating arsenic uptake from soil. The increasing availability of central resources on data from total diet studies and research investigations presents a need for personnel with diverse levels of skills in data
management and analysis. Training workshops and courses on the foundations and applications of visual analytics can contribute to global workforce development in food safety and environmental health. Research investigations could determine learning
gains accomplished through hardware and software for visual analytics. Finally, there is need to develop and evaluate informatics tools that have visual analytics capabilities in the domain of contaminants in foods.
Arsenic contamination of ground water and its health impact on population of district of Nadia, West Bengal, IndiaMazumder Debendra Nath; Ghosh Aloke; Majumdar Kunal; Ghosh Nilima; Saha Chandan; Mazumder Rathindra Nath (Wolters Kluwer Medknow Publications, 2010-01-01)<b>Background:</b> The global health impact and disease burden due to chronic arsenic toxicity has not been well studied in West Bengal. <b>Objective:</b> To ascertain these, a scientific epidemiological study was carried out in a district of the state. <b>Materials and Methods:</b> Epidemiological study was carried out by house-to-house survey of arsenic affected villages in the district of Nadia. A stratified multi-stage design has been adopted for this survey for the selection of the participants. A total number of 2297 households of 37 arsenic affected villages in all the 17 blocks were surveyed in the district. <b>Result:</b> Out of 10469 participants examined, prevalence rate of arsenicosis was found to be 15.43&#x0025;. Out of 0.84 million people suspected to be exposed to arsenic, 0.14 million people are estimated to be suffering from arsenicosis in the district. Highest level of arsenic in drinking water sources was found to be 1362 &#956;g/l, and in 23&#x0025; cases it was above 100 &#956;g/l. Majority of the population living in the arsenic affected villages were of low socio-economic condition, inadequate education and were farmers or doing physical labour. Chronic lung disease was found in 207 (12.81&#x0025;) subjects among cases and 69 (0.78&#x0025;) in controls. Peripheral neuropathy was found in 257 (15.9&#x0025;) cases and 136 (1.5&#x0025;) controls<i>.</i> <b>Conclusion:</b> Large number of people in the district of Nadia are showing arsenical skin lesion. However, insufficient education, poverty, lack of awareness and ineffective health care support are major factors causing immense plight to severely arsenic affected people.