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Klasios N, Birch A, Murillo AM, Tseng M. Warming temperatures exacerbate effects of microplastics in a widespread zooplankton species. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 349:123918. [PMID: 38574946 DOI: 10.1016/j.envpol.2024.123918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/15/2024] [Accepted: 04/01/2024] [Indexed: 04/06/2024]
Abstract
The emergence of microplastics as a global contaminant of concern has coincided with climate change induced temperature warming in aquatic ecosystems. Warmer temperatures have been previously demonstrated to increase the toxicity of certain contaminants, but it is currently unclear if microplastics are similarly affected by temperature. As aquatic organisms simultaneously face microplastic pollution and both increasing and variable temperatures, understanding how temperature affects microplastic toxicity is pertinent in this era of human-induced global change. In this study, we investigate the effects of environmentally relevant microplastic exposure to Daphnia pulex survival, reproduction, and growth at three different temperatures. To simulate an environmentally relevant exposure scenario, we created microplastics with physicochemical characteristics often detected in nature, and exposed organisms to concentrations close to values reported in inland waters and 1-2 orders of magnitude higher. The three temperatures tested in this experiment included 12 °C, 20 °C, and 24 °C, to simulate cool/springtime, current, and warming scenarios. We found the highest concentration of microplastics significantly impacted survival and total offspring compared to the control at 20 °C and 24 °C, but not at 12 °C. The adverse effect of high microplastic concentrations on total offspring at warmer temperatures was driven by the high mortality of the juveniles. We observed no effect of microplastics on time to first reproduction or average growth rate at any temperature. Warmer temperatures exacerbated microplastic toxicity, although only for concentrations of microplastics not currently observed in nature, but these concentrations are possible in pollution hotspots, through pulses pollution events or future worsening environmental contamination. The results of our study illustrate the continued need to further investigate climate change related co-stressors such as warming temperatures in microplastic and pollution ecology, through environmentally realistic exposure scenarios.
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Affiliation(s)
- Natasha Klasios
- University of British Columbia, Department of Zoology, 2212 Main Mall, Vancouver, BC, V6T 1Z4, Canada.
| | - Abigail Birch
- University of British Columbia, Department of Zoology, 2212 Main Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Aurelio Morales Murillo
- University of British Columbia, Department of Pharmaceutical Sciences, 2405 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Michelle Tseng
- University of British Columbia, Department of Zoology, 2212 Main Mall, Vancouver, BC, V6T 1Z4, Canada; University of British Columbia, Department of Botany, 2212 Main Mall, Vancouver, BC, V6T 1Z4, Canada
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Mai NTQ, Batjargal U, Kim WS, Kim JH, Park JW, Kwak IS, Moon BS. Microplastic induces mitochondrial pathway mediated cellular apoptosis in mussel (Mytilus galloprovincialis) via inhibition of the AKT and ERK signaling pathway. Cell Death Discov 2023; 9:442. [PMID: 38057300 DOI: 10.1038/s41420-023-01740-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 11/05/2023] [Accepted: 11/22/2023] [Indexed: 12/08/2023] Open
Abstract
Microplastics (MPs) is an escalating aquatic environmental crisis that poses significant threats to marine organisms, especially mussels. Here, we compare the cumulative toxic effects of the two most abundant morphotypes of MPs in the environment, microspheres, and microfibers, on the gill and digestive gland (DG) of Mytilus galloprovincialis in a dose-dependent (1, 10, and 100 mg/L) and time-dependent (1, 4, 7, 14, 21 days exposure) manner. DNA fragmentation assessment through TUNEL assay revealed consistency in the pattern of morphological disturbance degree and cell apoptosis proportions indicated by histopathological analysis. Upon the acute phase of exposure (day 1-4), gill and DG treated with low MPs concentration exhibited preserved morphology and low proportion of TUNEL+ cells. At higher concentrations, spherical and fibrous MP-induced structural impairments and DNA breakage occurred at distinct levels. 100 mg/L microfibers was lethal to all mussels on day 21, indicating the higher toxicity of the fibrous particles. During the chronic phase, both morphological abnormalities degree and DNA fragmentation level increased over time and with increasing concentration, but the differentials between the spherical and fibrous group was gradually reduced, particularly diminished in 10 and 100 mg/L in the last 2 weeks. Furthermore, analysis of transcriptional activities of key genes for apoptosis of 100 mg/L-day 14 groups revealed the upregulation of both intrinsic and extrinsic apoptotic induction pathway and increment in gene transcripts involving genotoxic stress and energy metabolism according to MP morphotypes. Overall, microfibers exert higher genotoxic effects on mussel. In response, mussels trigger more intense apoptotic responses together with enhanced energy metabolism to tolerate the adverse effects in a way related to the accumulation of stimuli.
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Affiliation(s)
- Nhu Thi Quynh Mai
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 38541, Korea
- Department of Integrative Biotechnology, Chonnam National University, Yeosu, 59626, Korea
| | - Ulziituya Batjargal
- Department of Integrative Biotechnology, Chonnam National University, Yeosu, 59626, Korea
| | - Won-Seok Kim
- Department of Ocean Integrated Science, Chonnam National University, Yeosu, 59626, Korea
| | - Ji-Hoon Kim
- Department of Ocean Integrated Science, Chonnam National University, Yeosu, 59626, Korea
| | - Ji-Won Park
- Department of Ocean Integrated Science, Chonnam National University, Yeosu, 59626, Korea
| | - Ihn-Sil Kwak
- Department of Ocean Integrated Science, Chonnam National University, Yeosu, 59626, Korea.
| | - Byoung-San Moon
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 38541, Korea.
- Department of Integrative Biotechnology, Chonnam National University, Yeosu, 59626, Korea.
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