2.01 Aquatic and terrestrial plant ecology, ecotoxicology and risk assessment (Part I)
2.01.T-01 Cationic and Anionic Silica Nanoparticles Reduce the Toxicity of the Pesticides Pentachlorophenol, Paraquat and Diflufenican to Algae
Frida Book1, Michael Persson2, Eric Carmona Martinez3, Tobias Lammel1 and Thomas Backhaus4, (1)University of Gothenburg, Sweden, (2)Chalmers Industriteknik, Sweden, (3)Helmholtz Center for Environmental Research - UFZ GmbH, Germany,
(4)University of Gothenburg Sweden, Sweden
Colloidal silica shows promising properties as efficient adsorbents for pollutants in water and hence reducing the pollutant’s bioavailability to aquatic organisms. To explore this, the present study investigated the toxicity of pesticides in mixtures with colloidal silica towards the freshwater green algae Raphidocelis subcapitata. Three spherical silica nanomaterials with different surface charge, weakly anionic, strongly anionic and cationic, were tested in binary mixtures with three differently charged pesticides: cationic paraquat, anionic pentachlorophenol and neutral diflufenican. The hypothesis was that the silica nanomaterials would bind oppositely charged pesticides and hence reduce the toxicity to algae. To test this theory, different nanomaterial concentrations (0.4-50 mg/L) were tested in mixtures with a fixed concentration of the pesticide known to reduce algae growth.
The results showed that the strongly anionic silica was able to reduce the growth inhibition of paraquat with up to 60%. The cationic nanomaterial reduced growth inhibition with 30-50 %. The cationic material also reduced the toxicity of diflufenican by 10-20 %. Adsorption of pesticides onto the various nanomaterials was further confirmed by chemical analysis with LC-MS. To conclude, colloidal silica were efficient adsorbents of pesticides, which led to a reduced bioavailability and toxicity to algae.
Keywords: silica, pesticides, algae, ecotoxicity
2.01.T-02 Ecotoxicity, Adaptation and Gene Expression of the Green Alga Raphidocelis subcapitata Towards the Herbicide Diflufenican
Daniela Gómez Martínez1, Anders Nilsson2, Rikard Tröger3, Henrik Jernstedt4, Adrian Clarke5, Henrik Nilsson6, Erik Kristiansson7 and Natàlia Corcoll2, (1)Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden, (2)University of Gothenburg, Sweden, Sweden, (3)Swedish University of Agricultural Sciences (SLU), Sweden, (4)Swedish University of Agricultural Sciences, Sweden, (5)University of Gothenburg Sweden, Sweden, (6)University of Gothenburg, Sweden, (7)Chalmers University of Technology, Sweden
Research on algal ecotoxicology towards herbicides has been mainly focused on short-term responses. However, the development of tolerance via physiological and genetic changes that allows algae to adapt in an ecological time scale to toxic substances,
remains poorly understood. This study aims to describe the ecotoxicity and adaptation mechanisms of the freshwater green microalga Raphidocelis subcapitata to the herbicide diflufenican, a carotenogenesis inhibitor commonly found in European agricultural streams. To do so, an adaptative laboratory experiment was performed for 90 days. R. subcapitata was exposed to three different concentrations of diflufenican with environmental and ecotoxicological relevance (i.e. 0, 10.7 and 310.5 ng/L).
During the first week of exposure, a decrease in growth rate up to 55.5%, carotenoid and xanthopylls pigments up to 38.7%, and PSII photosynthetic activity up to 17%, indicated that diflufenican had a negative effect on all these three physiological endpoints.
This stress phase was followed by a recovery and an adaptation phase, during which the apical endpoints of the exposed alga returned to similar values compared to their controls. Diflufenican-adapted alga developed tolerance to diflufenican exposure (higher EC50s). However, the adapted alga did not show differences in fatty acids composition, indicating that changes in the lipid composition of the cell membrane were not involved in adaptation processes. R. subcapitata showed a removal rate capacity of 10% both at the stress and adaptation phases, suggesting that adaptation mechanisms are not linked with an increase in biodegradation capacity. Our findings reflect the high sensitivity of algae to diflufenican and its ability to adapt, as well as the importance of investigating the effects of herbicides after long-term exposures. Finally, a planned transcriptomic analysis will potentially highlight the genes and enzymes that play a role in bioaccumulation, detoxification and overall adaptation processes that allow the cells to survive under different concentrations of diflufenican (evolutionary ecotoxicology), as well as their implications in ecological functions.
2.01.T-03 Effects of Environmental Parameters and Toxicants on Lemna minor Growth: An Integrated Experimental and Modelling Approach
Ms. Isabelle Van Dyck, Belgian Nuclear Research Centre (SCK CEN), Belgium
Living organisms can be exposed to to radionuclides and heavy metals. Large areas, including surface waters, are contaminated with pollutants and in need for remediation. Phytotechnologies use biological processes of living plants to remove, degrade or stabilise pollutants in environmental compartments such as soil, water and air. Phytoremediation is already known as an efficient site remediation technology for various types of pollutants and can be used as a complementary waste water treatment technique for specific scenarios. Lemna minor, commonly known as duckweed, has the possibility to absorb and accumulate pollutants in its biomass and can therefore be used for remediation of contaminated water.It is important to understand the behaviour of L. minor to remove pollutants from the aquatic environment, assessing its remediation capability and proposing proper remediation strategies. A mathematical model for L. minor growth and transfer of pollutants can help to evaluate and select phytoremediation as appropriate remediation strategy for specific scenarios. Building on a previous growth model, a more comprehensive growth model is developed by incorporating the impact of additional environmental conditions using an experimental and modelling approach. To study growth changes of L. minor, experiments are performed under different environmental conditions where temperature, light intensity, photoperiod and nutrient compositions are varied from optimal to very low or high conditions.For each experimental condition, growth curves are created and used to optimise these environmental parameters in the growth model.
After an overall optimisation and validation of the global growth model, the model will serve as a basis for the remediation model, where new insights on uptake of radionuclides and other pollutants can be incorporated. For several (mixtures of) pollutants, uptake and dose response curves are being made as well as time-dependent uptake and release curves. In addition, experiments that study the effects of pollutants on photosynthesis and pigment, starch and soluble sugar content of L. minor are also performed. Together with the research for the development and optimisation of the growth model, these first (non-published) pollutant results will be presented at the conference. Finally, when the outcome of the Lemna based system can be model-predicted, it can be applied as an efficient, cost-effective and eco-friendly water depollution technique.
2.01.T-04 Toxicogenomic Analysis of Ecotoxic Modes of Action in Lemna minor
Alexandra Loll1, Hannes Armin Reinwald1, Dr. Steve Uwa Ayobahan1, Gabriela Salinas2, Christoph Schaefers1, Karsten Schlich3, Gerd Hamscher4 and Sebastian Eilebrecht1, (1)Fraunhofer IME - Institute for Molecular Biology and Applied Ecology, Germany, (2)NGS - Integrative Genomics Core Unit, Germany, (3)Ecotoxicology, Fraunhofer IME - Institute for Molecular Biology and Applied Ecology, Schmallenberg, Germany, (4)Justus-Liebig-University Giessen, Germany
Due to its high reproduction rate, Lemna minor is one of the most frequently used aquatic model organisms in ecotoxicology. As a primary producer, it is an important part of the ecosystem and therefore an indicator for water quality. If the development of the plant is influenced by external factors such as xenobiotics, this will not only have a direct effect on the phenotype of the plant, but also indirectly affect other organisms. Therefore, L. minor is commonly used for the evaluation of toxic effects on water plants by newly developed substances such as pharmaceuticals or pesticides. In this study, L. minor was used for investigations of ecotoxic modes-of-action (MoA) at the molecular level. Therefore transcriptomics and proteomics methods were applied to a shortened version of the OECD guideline test No. 221 conducted with low effect concentrations of two model substances – the
pharmaceutical atorvastatin and the herbicide bentazon. Previous studies have shown that, besides photosynthesis inhibition, bentazon additionally has a similar MoA as atorvastatin, whose action is based on the inhibition of the key enzyme of cholesterol and phytosterol synthesis 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR).The goal of our study was to link the determined molecular fingerprint of each substance with both its hazardous effects on the test organism and its MoA in order to identify possible biomarkers. Therefore, we applied bioinformatics approaches to functionally annotate the previously unannotated reference genome of L. minor. Our functional annotation pipeline is in principle applicable to any organism with an available reference genome and thus greatly facilitates the identification of gene functions for poorly annotated organisms. For both test substances, significant changes in gene expression were observed in the context of a shortened ecotoxicity test with low effect concentrations. These molecular changes preceded the physiological effects and may, therefore, be consulted for early predictions.
2.01.T-05 Selecting and Testing Ecologically Relevant Macrophytes and Endpoints in Mesocosm Studies
Marie Brown1, Nadine Taylor1, Hanna Samantha Schuster1, Zoe Leanne Jones2 and Katie Smith1, (1)Cambridge Environmental Assessments, United Kingdom, (2)Cambridge Environmental Assessments, UK
Aquatic macrophytes play an ecologically important role in the ecosystem by providing shelter, food and performing essential biological and ecological functions. Aquatic freshwater mesocosms are designed to represent edge of field water bodies by creating a habitat that will support communities of aquatic macrophytes, algae, zooplankton and macroinvertebrates in a contained system. Therefore the macrophytes included in these systems should reflect the communities found in the natural environment.
The EFSA guidance document on tiered risk assessment for plant protection products (PPP) for aquatic organisms in edge-of-field surface waters, makes recommendations for a minimum of 8 sensitive/vulnerable taxa with acceptable minimum detectable difference (MDD) values to be tested. However there is little guidance on selecting representative macrophytes that will survive in these systems, or on the selection of appropriate endpoints that will provide regulatory acceptable data. In addition, the limited number of standard macrophyte laboratory tests makes it challenging to determine which species may be sensitive to any given stressor.The aim of this presentation is to share our expertise on the selection of macrophyte species and techniques for assessing plant growth and health in mesocosm studies. We hope that by sharing our considerations for macrophyte selection and endpoint evaluation in mesocosm studies we can open up the discussion on the relevance of mesocosm studies, particularly within the future of risk assessment for macrophyte communites. We will also demonstrate the CEA sloped mesocosm design as a reference study in order to derive more reliable and robust population and community level endpoints using macrophytes as an example.
These results can be used to inform the experimental design of future macrophyte mesocosm studies such that the results meet the EFSA requirements for sensitive/vulnerable taxa with acceptable MDD values for regulatory use.
2.01 Aquatic and terrestrial plant ecology, ecotoxicology and risk assessment (Part II)
2.01.T-06 Combined Impact of Agricultural Run-Off and Warming on Primary Producers and Consumers in Agricultural Streams
Elisabeth Maria Gross1, Joey Allen2, Didier Ortiz2, Vinita Vijayaraj3, Vincent Felten3, Martin Laviale4, Nora Kipferler5, Bastian Polst6, Grégorio López Moreira Mazacotte7, Franz Hölker8, Joséphine Leflaive9, Mechthild Schmitt-Jansen10, Sabine Hilt8 and Herwig Stibor5, (1)CNRS UMR 7360 / UniversitÈ de Lorraine, France, (2)CNRS - LIEC UMR7360, France, (3)Universite de Lorraine, France, (4)University of Lorraine, France, (5)Ludwig-Maximilians-University Munich, Germany, (6)UFZ - Helmholtz Centre for Environmental Research, Germany, (7)Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany, (8)Leibniz Institute of Freshwater Ecology and Inland Fisheries, Germany, (9)University of Toulouse, France, (10)UFZ - Helmholz Ctre Environm. Research, Germany
Ditches or small streams in agricultural landscapes are among the first to be affected by agricultural run-off (ARO) composed of nutrients and pesticides. In artificial streams, we investigated the effects of warming and ARO on the temporal dynamics of different types of primary producers (macrophytes, periphyton, phytoplankton, filamentous blanketing algae) and primary consumers. Our hypotheses were that warming would favour early macrophyte development and that ARO would favour
filamentous algae over macrophytes in these systems. The experiment was based on a 2 x 2 factorial-design (warming, ARO) with each 4 replicates. Channels had an upstream compartiment containing Glyceria maxima and Dreissena polymorpha. The
downstream channels were planted with root or rhizome sections of three submerged macrophytes, received an inoculum of periyphyton, alder leaf litter, Gammarus roeseli and Lymnaea stagnalis . The effect of ARO on primary producers was very distinct. ARO significantly enhanced the development of blanketing filamentous algae and periphyton, while warming had only minor effects. The high dose of nitrate applied with ARO vanished very fast, probably absorbed by filamentous algae and periphyton. When filamentous algae collapsed towards the end of the experiment, phytoplankton increased, probably triggered by a massive liberation of phosphorus. Macrophytes developped very late in the cold spring in 2021. Potamogeton perfoliatus dominated, profiting most from warming. ARO negatively affected its development at a later stage in the experiment, suggesting indirect effects caused by competition with blanketing filamentous algae. All other macrophytes showed no clear response to warming or ARO. ARO had a strong effect on the reproduction of gammarids and snails, likely caused by pesticides and leading to a reduced periphyton control. ARO and warming strongly enhanced mortality of mussels. Leaf litter degradation was enhanced by warming, but not affected by ARO. Submerged macrophytes usually appear only after the water temperature reaches a certain temperature, and often have to compete against a massive development of blanketing algae. Our study aims to determine whether ARO affected this dynamic. Combined nitrate and pesticide effects led to a range of direct and indirect effects on primary producers and consumers, with the most visible being the strong development of filamentous green algae, but also effects on periphyton, gammarids and snails.
2.01.T-07 Uptake, Translocation, and Metabolism of Different Contaminants of Emerging Concern in Radish Crops Grown Under Controlled Conditions
Nicola Montemurro1, Francesc Labad Roig2 and Sandra Perez3, (1)Environmental Chemistry, Jordi Girona 18-26, null, Barcelona, Spain, (2)CSIC - Spanish National Research Council, Spain, (3)CSIC, Spain
The constant search for good quality water for agriculture has meant that water resources are under pressure in many regions, representing the main limiting factor for social welfare and economic development of many countries.Treated wastewater represents a valid alternative to the consumption of good quality water for the irrigation of agricultural crops. However, this practice could contribute to the spread of some organic contaminants in the soil and in the environment. In fact, the presence of contaminants of emerging concern (CECs) is notoriously reported in effluents of wastewater treatment plants (WWTPs), since conventional treatments are not specifically designed for their removal. Their impact is of particular relevance for the disposal and
re-use of wastewater in agriculture due to the use and accumulation of CECs in food crops and the consequent spread in the food chain and ecosystems.Radish (Raphanus sativus) is often used as a model plant to investigate the fate of organic contaminants in plants given its short growing cycle and its potential ability to accumulate contaminants in the roots. In fact, the contaminants could enter the plants from the soil through the absorption of the roots, and constitute a potential risk to food safety. In addition, to accumulate in the root, these compounds can give rise to phenomena of translocation in the leaf parts or potential metabolism with the formation of a variety of transformation products.However, only a few studies were designed to evaluate the uptake and the potential metabolism of pharmaceuticals in radish and only for a limited range of compounds [1, 2].This study was therefore planned to evaluate the influence of a wide range of pharmaceutical compounds into radish crops irrigated with artificially contaminated water at 10 and 100 µg L-1. In addition to uptake and translocation, the metabolic transformation of pharmaceuticals was also evaluated.Pharmaceuticals in radish roots and leaf material were extracted by one-step modified QuEChERS method [3].
using whereas the detection was performed using the new SCIEX X500R QTOF-MS, a compact hybrid quadrupole time-of-flight mass spectrometer combining advantages of TOF and QqQ systems with accurate mass. In this study, we investigated the use of MRMHR and MS/MSAll with SWATH acquisition for the targeted analysis (using reference standards) and non-target screening on a routine basis.
2.01.T-08 Comparative Transcriptomic Analysis of Brassica Napus L. Grown on Soils Contaminated by Metallurgical Industry Reveals New Insights Into PLANTS' Response to Metal Stress
Marta Jaskulak1, Katarzyna Zorena2 and Franck Vandenbulcke3, (1)Medical University of Gdansk, Poland, (2)Medical University of Gdansk, Poland, Poland, (3)University of Lille, France
Problem with heavy metal-contaminated soils is increasing significantly throughout the world due to industrialization, mining operations, improper waste, and water treatment. Although the response of plants to single metal contamination in lab condition are extensively researched, the aspect of mixed toxicity, which usually occurs in the natural world, is often overlooked. Our knowledge and understanding of the specific response to synergistic stressors on plants are strictly limited. The main aim of the experiment was to assess the transcriptomic changes in leaves of Brassica napus after exposure to soil contaminated with a vast range of heavy metals due to the past metallurgical activity in the area. Specifically, the contaminated soil contained over 20 mg/kg of cadmium (Cd), over 1100 mg/kg of lead (Pb), and over 700 mg/kg of Zinc (Zn). Thus, the purpose was to identify how such actual industrial contamination influences plants on the transcriptome level to broaden our
understanding of the actual environmental impact. The experiment was performed in actual field conditions on 6 plots and lasted for the entire vegetative season. All the cDNA libraries of B. napus were sequenced using an Illumina HiSeq™ 4000 platform. The sequencing generated 21 688 894 to 29 810 359 raw paired reads for each sample. The soil supplementation with sewage sludge caused 10 025 genes to be differentially expressed with the False Detection Threshold at a level of 0.001. The gene ontology analysis showed that most differentially expressed genes were related, among others, to plants' response to stress, cell death, xenobiotics, hormone production, and transport. The project consisted of a first study dealing with the influence of long-term exposure to mixed metal toxicity application on plant metabolism on a transcriptomic level. Acknowledgement - Research was funded by National Science Centre, Poland, 2018/31/N/NZ9/01742
2.01.T-09 Drifting Towards HIGHER Tiers: Developing a Regulatory Greenhouse Test Method for Non-Target Terrestrial PLANTS Mimicking Realistic Drift Exposure to Refine the Risk Assessment of Herbicides
Rena Jutta Irene Isemer1, Clare Butler Ellis2, Clive Tuck2, Andrew Lane2, Stefanie Nöding3, Arne Hantel3, Daniela Jans3 and Dr.
Andrew C. Chapple4, (1)Crop Science, Bayer Crop Science, Germany, (2)Silsoe Spray Applications Unit Ltd, United Kingdom, (3)Bayer Crop Science, Germany, (4)Environmental Safety, Bayer Crop Science, Germany
The risk assessment for non-target terrestrial plants (NTTPs) in Europe rests on two pillars: endpoints derived of standard guideline tests and exposure estimations derived from Rautmann drift value tables. Both pillars have been challenged in recent years. Endpoints are critizised as being not realistic enough while drift values will be replaced by more conservative drift values (SETAC DRAW). Accordingly, a more realistic higher tier approach leading to a simultaneous refinement of effects and exposure would be desireable. One possibility could be a recently developed field study design assessing effects of a herbicide on plants after exposure via drift [Moore et al. 2021. Integr Environ Assess Manag]. As the approach is time-, labour- and cost-intense, a laboratory Plant Intermediate Tier Test (PITT) design is proposed. This study design will follow the guideline protocol for NTTP greenhouse tests but exposure will mimic drift such as the plants would experience in the field. Here, we present the spray cabin set-up as well as results of modelling and measurements used for calibation of the spray cabinet. Spray cabinets will be adapted as follows: (a) volume lowered, (b) use spinning disc nozzle in order to generate a droplet spectrum similar to that of a drift plume, and (c) place plants on a conveyer belt moving them through the spray cloud so that the relative movement of the plant and spray cloud are similar to that of a stationary plant in the field and a drifting spray plume. The SiMoD boom sprayer model was used to predict the quantity and droplet spectrum of drift reaching NTTPs in order to determine how the spray cabinet needs to be calibrated when performing a PITT trial. The quantity of spray deposited is expected to correlate with the quantity of airborne spray. The main factors influencing the droplet size are the wind speed and distance downwind. Interestingly, nozzle design has a very small effect on downwind droplet size distributions. The proposed Plant Intermediate Tier Test (PITT) method could serve as as refinement option for the NTTP risk assessment, refining exposure and effects at the same time while still being labor-, cost- and time-efficient.
2.01.T-10 Tbd 4 TBD
2.01 Aquatic and terrestrial plant ecology, ecotoxicology and risk assessment (Virtual Only)
2.01.V-01 Algal Preservation and Enumeration Techniques for Use in Micro and Mesocosm Studies
Zoe Leanne Jones, Hanna Samantha Schuster, Katie Smith, Marie Brown and Nadine Taylor, Cambridge Environmental Assessments, United Kingdom
Standard, lower tier, testing strategies for the effects of Plant Protection Products (PPP’s) on algae are focused on single species studies and may not provide adequate protection for these important communities. Higher tier approaches, such as
micro/mesocosm studies are designed to represent edge of field water bodies by creating a habitat that will support communities of aquatic macrophytes, algae, zooplankton and macroinvertebrates in a contained system. Therefore, these experimental systems offer a more comprehensive analysis of the effects of PPPs on these communities. Whilst definitively more representative of natural systems, this increase in complexity brings further challenges. Freshwater algal communities are very diverse, the taxonomic identification of these species is difficult, and requires trained taxonomists. When designing these studies,
consideration needs to be given to the methods employed for sampling, preservation and enumeration to ensure all steps are fit for purpose. The sampling processes need to offer a true representation of the algal assemblages present. One of the major difficulties in sampling freshwater alage is preservation. The need for preservation at all should be considered as they will damage algal morphology over time, however this step is often a necessity in larger, long-term studies. Following sample collection,
enumeration is necessary to collect the data needed to derive ecotoxicological endpoints, e.g. MDD’s, ECx and NOEC’s. As with the sampling procedures, this process needs to use sub-samples that accurately reflect the whole test system. Here we present and assess different methods that can be used for the sampling preservation and enumeration of freshwater phytoplankton and periphyton. We discuss the pro’s and cons of these approaches and present methods for the analysis of microcosm and mesocosm algal samples that have provided the most reliable and robust statistical data from studies conducted at CEA.
2.01.V-02 Assessing the Acute Toxicity of Individual Polycyclic Aromatic Compounds to Fucoid Macroalgae (Fucus vesiculosus) Using a Germination Assay
Dr. Danielle Philibert1, Rob Holland2, Dave Goodwin1 and Benjamin de Jourdan1, (1)Huntsman Marine Science Centre, Canada, (2)Oil Spill Response Limited, United Kingdom
Of the 1000s of components within crude oil, polycyclic aromatic compounds (PACs) are thought to be the component of crude oil primarily responsible for toxicity. Due to the complexity of a crude oil spill, stakeholders must rely on mathematical models to predict and assess the impacts of a spill on aquatic life. Oil spill models rely on quantitative structure-activity relationships (QSARs) like the target lipid model (TLM) to estimate the toxicity of different components found within crude oil, as well as species sensitivity distributions (SSDs) to determine species at risk if exposed. Macroalgae play a critical role in both freshwater and marine ecosystems and function as both primary producers and as a habitat for other aquatic life, however very little research has been done to determine the sensitivity of macroalgae to PAC exposure. The aim of the study was to generate toxicity data to determine the sensitivity of Fucus vesiculosus, a common intertidal brown seaweed, to PACs, and to assess the impacts of different environmental conditions on observed toxicity. Test solutions were generated using passive dosing with
polydimethylsiloxane (PDMS) O-rings left to equilibrate in glass petri-dishes for 24-48 hours. To generate zygotes for the germination assay, the receptacles of sexually mature plants were dissected, sexed, and stored in the dark at 4°C until use. Using previously published spawning protocols, zygotes were generated and allocated to glass slides submerged within the glass petri-dishes Germination success was assessed at 3 and 5 dpf. Of the compounds tested and assessed at 3 dpf, dibenzothiophene had the most significant impact on germination rate (EC50 = 1.59 µmol/L), followed by naphthalene, and methylnaphthalene (EC50 = 5.46 µmol/L, EC50 = 8.07 µmol/L respectively). There was a linear relationship between the log (LC50) and log (Kow) of the PACs as described in the TLM, and the critical target lipid body burden (CTLBB) was determined to be 29.1 ± 12.4 ?mol/goctanol . The results from this study suggests the zygotes of F. vesiculosus are one of the more sensitive species and life stages included in the TLM model and would serve as a good model species to be included in crude oil toxicity tests. The data generated in this study can be used to better understand the sensitivity of macroalgae to PAC exposure, and to assess the impact of shoreline oiling on the germination success of Fucus algae.
2.01.V-03 Effects of Tire Fragments Toxicity on the Vigna radiata
Lia Kim, Tae-yang Lee, Haemi Kim and Prof. Youn-Joo An, Konkuk University, Korea, South
Tire wear particles, generated from the roads, is one of the main sources of microplastics in the terrestrial environment. This study evaluated the effects of tire particles on mung bean (Vigna radiata). Three different types of tire particles (bicycle (B), car (C), and electric scooter (ES)) were exposed to mung bean for 4 weeks and the growth inhibition were measured. Additionally, the tire fragments were leachate for 4 weeks to analyzing the toxicant leaching from the tire fragments. There was some shoot growth inhibition on the exposure group of ES tire fragments. The adverse effects of tire fragments were expected to be induced by the chemical leaching from the tire particles, that the ICP-MS and non-target GC-MS were conducted on three types of leachates to figure out the major toxicants. According to the chemical analysis the tire leachates contained the high concentrations of zinc and benzothiazole in all three leachates, which were used as the additives of plastic-products. Especially in ES leachate, the chrome and lead were detected and showed the dominant correlation with the plant toxicity. Also, there was some size difference between the tire fragments and the ES tire fragments have the small size compared to the others. This finding of this study suggests that tire fragments from the land release the toxic components and the size of tire particles could also induce the plant toxicity.
Acknowledgement - This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and future planning (2020R1A2B5B02001734).