TY - JOUR A1 - Pawlak, Julia A1 - Noetzel, Dominique Christian A1 - Drago, Claudia A1 - Weithoff, Guntram T1 - Assessing the toxicity of polystyrene beads and silica particles on the microconsumer Brachionus calyciflorus at different timescales JF - Frontiers in Environmental Science N2 - Environmental pollution by microplastics has become a severe problem in terrestrial and aquatic ecosystems and, according to actual prognoses, problems will further increase in the future. Therefore, assessing and quantifying the risk for the biota is crucial. Standardized short-term toxicological procedures as well as methods quantifying potential toxic effects over the whole life span of an animal are required. We studied the effect of the microplastic polystyrene on the survival and reproduction of a common freshwater invertebrate, the rotifer Brachionus calyciflorus, at different timescales. We used pristine polystyrene spheres of 1, 3, and 6 µm diameter and fed them to the animals together with food algae in different ratios ranging from 0 to 50% nonfood particles. As a particle control, we used silica to distinguish between a pure particle effect and a plastic effect. After 24 h, no toxic effect was found, neither with polystyrene nor with silica. After 96 h, a toxic effect was detectable for both particle types. The size of the particles played a negligible role. Studying the long-term effect by using life table experiments, we found a reduced reproduction when the animals were fed with 3 µm spheres together with similar-sized food algae. We conclude that the fitness reduction is mainly driven by the dilution of food by the nonfood particles rather than by a direct toxic effect. KW - microplastics KW - rotifer KW - freshwater KW - natural particle KW - toxicity KW - environmental pollution Y1 - 2022 U6 - https://doi.org/10.3389/fenvs.2022.955425 SN - 2296-665X SP - 1 EP - 11 PB - Frontiers CY - Lausanne, Schweiz ER - TY - JOUR A1 - Wright, Stephanie L. A1 - Ulke, Jannis A1 - Font, Anna A1 - Chan, Ka Lung Andrew A1 - Kelly, Frank J. T1 - Atmospheric microplastic deposition in an urban environment and an evaluation of transport JF - Environment international N2 - Microplastics are a global environmental issue contaminating aquatic and terrestrial environments. They have been reported in atmospheric deposition, and indoor and outdoor air, raising concern for public health due to the potential for exposure. Moreover, the atmosphere presents a new vehicle for microplastics to enter the wider environment, yet our knowledge of the quantities, characteristics and pathways of airborne microplastics is sparse. Here we show microplastics in atmospheric deposition in a major population centre, central London. Microplastics were found in all samples, with deposition rates ranging from 575 to 1008 microplastics/m(2)/d. They were found in various shapes, of which fibrous microplastics accounted for the great majority (92%). Across all samples, 15 different petrochemical-based polymers were identified. Bivariate polar plots indicated dependency on wind, with different source areas for fibrous and non-fibrous airborne microplastics. This is the first evidence of airborne microplastics in London and confirms the need to include airborne pathways when consolidating microplastic impacts on the wider environment and human health. KW - microplastics KW - atmospheric deposition KW - air pollution KW - urban Y1 - 2020 U6 - https://doi.org/10.1016/j.envint.2019.105411 SN - 0160-4120 SN - 1873-6750 VL - 136 PB - Elsevier, Pergamon Press CY - New York, NY [u.a.] ER - TY - JOUR A1 - Drago, Claudia A1 - Pawlak, Julia A1 - Weithoff, Guntram T1 - Biogenic aggregation of small microplastics alters their ingestion by a common freshwater micro-invertebrate JF - Frontiers in Environmental Science N2 - In recent years, increasing concerns have been raised about the environmental risk of microplastics in freshwater ecosystems. Small microplastics enter the water either directly or accumulate through disintegration of larger plastic particles. These particles might then be ingested by filter-feeding zooplankton, such as rotifers. Particles released into the water may also interact with the biota through the formation of aggregates, which might alter the uptake by zooplankton. In this study, we tested for size-specific aggregation of polystyrene microspheres and their ingestion by a common freshwater rotifer Brachionus calyciflorus. The ingestion of three sizes of polystyrene microspheres (MS) 1-, 3-, and 6-mu m was investigated. Each MS size was tested in combination with three different treatments: MS as the sole food intake, MS in association with food algae and MS aggregated with biogenic matter. After 72 h incubation in pre-filtered natural river water, the majority of the 1-mu m spheres occurred as aggregates. The larger the particles, the higher the relative number of single particles and the larger the aggregates. All particles were ingested by the rotifer following a Type-II functional response. The presence of algae did not influence the ingestion of the MS for all three sizes. The biogenic aggregation of microspheres led to a significant size-dependent alteration in their ingestion. Rotifers ingested more microspheres (MS) when exposed to aggregated 1- and 3-mu m MS as compared to single spheres, whereas fewer aggregated 6-mu m spheres were ingested. This indicates that the small particles when aggregated were in an effective size range for Brachionus, while the aggregated larger spheres became too large to be efficiently ingested. These observations provide the first evidence of a size- and aggregation-dependent feeding interaction between microplastics and rotifers. Microplastics when aggregated with biogenic particles in a natural environment can rapidly change their size-dependent availability. The aggregation properties of microplastics should be taken into account when performing experiments mimicking the natural environment. KW - microplastics ingestion KW - Brachionus calyciflorus KW - aggregation KW - microplastics KW - polystyrene KW - functional response Y1 - 2020 U6 - https://doi.org/10.3389/fenvs.2020.574274 SN - 2296-665X VL - 8 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Kim, Shin Woong A1 - Leifheit, Eva F. A1 - Maaß, Stefanie A1 - Rillig, Matthias C. T1 - Time-dependent toxicity of tire particles on soil nematodes JF - Frontiers in Environmental Science N2 - Tire-wear particles (TWPs) are being released into the environment by wearing down during car driving, and are considered an important microplastic pollution source. The chemical additive leaching from these polymer-based materials and its potential effects are likely temporally dynamic, since amounts of potentially toxic compounds can gradually increase with contact time of plastic particles with surrounding media. In the present study, we conducted soil toxicity tests using the soil nematode Caenorhabditis elegans with different soil pre-incubation (30 and 75 days) and exposure (short-term exposure, 2 days; lifetime exposure, 10 days) times. Soil pre-incubation increased toxicity of TWPs, and the effective concentrations after the pre-incubation were much lower than environmentally relevant concentrations. The lifetime of C. elegans was reduced faster in the TWP treatment groups, and the effective concentration for lifetime exposure tests were 100- to 1,000-fold lower than those of short-term exposure tests. Water-extractable metal concentrations (Cr, Cu, Ni, Pb, and Zn) in the TWP-soils showed no correlation with nominal TWP concentrations or pre-incubation times, and the incorporated metals in the TWPs may be not the main reason of toxicity in this study. Our results show that toxic effects of TWPs can be time-dependent, both in terms of the microplastic particles themselves and their interactions in the soil matrix, but also because of susceptibility of target organisms depending on developmental stage. It is vital that future works consider these aspects, since otherwise effects of microplastics and TWPs could be underestimated. KW - Caenorhabditis elegans KW - exposure time KW - lifetime KW - microplastics KW - soil KW - incubation Y1 - 2021 U6 - https://doi.org/10.3389/fenvs.2021.744668 SN - 2296-665X VL - 9 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Drago, Claudia A1 - Weithoff, Guntram T1 - Variable Fitness Response of Two Rotifer Species Exposed to Microplastics Particles BT - The Role of Food Quantity and Quality JF - Toxics N2 - Plastic pollution is an increasing environmental problem, but a comprehensive understanding of its effect in the environment is still missing. The wide variety of size, shape, and polymer composition of plastics impedes an adequate risk assessment. We investigated the effect of differently sized polystyrene beads (1-, 3-, 6-µm; PS) and polyamide fragments (5–25 µm, PA) and non-plastics items such as silica beads (3-µm, SiO2) on the population growth, reproduction (egg ratio), and survival of two common aquatic micro invertebrates: the rotifer species Brachionus calyciflorus and Brachionus fernandoi. The MPs were combined with food quantity, limiting and saturating food concentration, and with food of different quality. We found variable fitness responses with a significant effect of 3-µm PS on the population growth rate in both rotifer species with respect to food quantity. An interaction between the food quality and the MPs treatments was found in the reproduction of B. calyciflorus. PA and SiO2 beads had no effect on fitness response. This study provides further evidence of the indirect effect of MPs in planktonic rotifers and the importance of testing different environmental conditions that could influence the effect of MPs. KW - microplastics KW - population growth rate KW - polystyrene KW - polyamide KW - silica beads KW - fitness response KW - rotifers KW - Brachionus fernandoi KW - Brachionus calyciflorus KW - egg ratio Y1 - 2021 U6 - https://doi.org/10.3390/toxics9110305 SN - 2305-6304 VL - 9 IS - 11 PB - MDPI CY - Basel ER -