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Start Over Author "Diana Campos" Journal ecotoxicology and environmental safety
3 results on '"Diana Campos"'

1. Lumbriculus variegatus (oligochaeta) exposed to polyethylene microplastics: biochemical, physiological and reproductive responses

Author

Carlos JM. Silva, Ana L. Patrício Silva, Diana Campos, Amadeu MVM. Soares, João LT. Pestana, and Carlos Gravato

Subjects
Plastic pollution, Aquatic macroinvertebrates, Sublethal effects, Oxidative stress, Microplastics ingestion, Environmental pollution, TD172-193.5, Environmental sciences, GE1-350
Abstract

Freshwater sediments are a repository of microplastics (MPs) resulting from inland anthropogenic activities. Benthic invertebrates, particularly endobenthic sediment–ingesting species such as the annelid Lumbriculus variegatus (blackworm), are commonly found in contaminated sediments where they likely find and ingest MPs. In the present study, L. variegatus was exposed to concentrations between 0.51 and 20 g kg−1 dry sediment of four size-classes of irregularly-shaped polyethylene MPs (PE-MPs; size-class A: 32–63, B: 63–125, C: 125–250 and D: 250–500 μm) for 48 h to assess their sub-cellular responses to particles ingested, and for 28 days to determine chronic effects on worm's reproduction and biomass.After the short-term exposure (48 h), number of PE-MPs in blackworms' gut were related to MPs concentration in the sediment. In general, PE-MPs ingestion by blackworms induced depletion of their energy reserves (e.g., sugars in all size classes and lipids in the size-classes of PE-MPs > 125 μm), concomitant with the activation of antioxidant and detoxification mechanisms (increased level of total glutathione in all size-classes, and increased glutathione-S-transferase activity in PE-MPs > 250 μm), preventing lipid peroxidation. In addition, it was observed a reduction of aerobic energy production (decreased activity of the electron transport system) and a slight increase in neurotransmission (cholinesterase activity). After a long-term exposure (28 d), the presence and ingestion of PE-MPs did not affect reproduction and biomass of L. variegatus.The activation and efficiency of the antioxidant and detoxification mechanisms allied with the anatomy and physiology of L. variegatus, its feeding strategy and potentially dynamic ingestion/egestion capacity seem to be key features preventing MP deleterious effects under short- and chronic-exposures. Considering the MPs levels reported for freshwater sediments, and despite evidence of MPs ingestion and some sub-organismal effects, our results suggest no adverse impacts of PE-MPs contamination on L. variegatus populations fitness.This study applies an integrative approach in which data concerning the ingestion of different sized MPs and subsequent sub-cellular and apical responses are delivered, raising knowledge on endobenthic invertebrates’ strategies to potentially overcome MP toxicity in field contaminated sites.

Published
2021
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2. Toxicity of organic UV-filters to the aquatic midge Chironomus riparius

Author

Vladimír Žlábek, Carlos Gravato, João L.T. Pestana, Oksana Golovko, Amadeu M.V.M. Soares, Diana Campos, and Carla Quintaneiro

Subjects
Male, 010504 meteorology & atmospheric sciences, Health, Toxicology and Mutagenesis, ved/biology.organism_classification_rank.species, 010501 environmental sciences, 01 natural sciences, Chironomidae, Toxicology, Benzophenones, chemistry.chemical_compound, medicine, Animals, Glutathione Transferase, 0105 earth and related environmental sciences, Invertebrate, Chironomus riparius, Larva, biology, ved/biology, Public Health, Environmental and Occupational Health, Neurotoxicity, General Medicine, Catalase, biology.organism_classification, medicine.disease, Pollution, Camphor, Octocrylene, Acrylates, chemistry, Environmental chemistry, Midge, Toxicity, Acetylcholinesterase, biology.protein, Female, Sunscreening Agents, Water Pollutants, Chemical
Abstract

Despite the frequent detection of organic ultraviolet-filters (UV-filters) in freshwater sediments, there is a lack of ecotoxicological data undermining a correct risk assessment for these emerging contaminants. The present study assessed the effects of three of the most commonly used UV-filters (benzophenone-3 - BP3; 3-(4-methylbenzylidene)camphor - 4-MBC and octocrylene - OC) on Chironomus riparius life history and biochemical responses. Standard ecotoxicological assays confirmed that all compounds impaired growth of C. riparius larvae and induced developmental effects such as delayed emergence and a reduction of imagoes weight. Concerning the biochemical responses analysed no evidences of oxidative damage in lipids or neurotoxicity (tested assessing acetylcholinesterase activity) were observed for any of the tested compounds. However, 4-MBC exposure induced a decrease in catalase activity and an increase in glutathione-S-transferase activity at 14.13mg/Kg while OC exposure caused an increase in total glutathione levels at 0.23 and 18.23mg/Kg. Exposure to all UV-filters tested, increased energy consumption on C. riparius with significant differences above 1.00mg/Kg for BP3, 0.09mg/Kg for 4-MBC and 2.13mg/Kg for OC. These results suggest that environmental relevant concentrations of UV-filters can cause deleterious effects to aquatic benthic species, such as C. riparius, and call for further research concerning effects of organic UV-filters on natural invertebrate communities and ecosystem functioning.

Published
2017
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3. Assessment of thiamethoxam toxicity to Chironomus riparius

Author

Andreia C.M. Rodrigues, João L.T. Pestana, Amadeu M.V.M. Soares, Ganna Fedorova, Renato de Almeida Sarmento, Diana Campos, Althiéris de Souza Saraiva, Vladimír Žlábek, and Carlos Gravato

Subjects
Insecticides, Insecta, Aché, Health, Toxicology and Mutagenesis, ved/biology.organism_classification_rank.species, 0211 other engineering and technologies, Zoology, Fresh Water, 02 engineering and technology, 010501 environmental sciences, Biology, 01 natural sciences, Freshwater ecosystem, Chironomidae, Toxicology, Neonicotinoids, chemistry.chemical_compound, Oxazines, Animals, Chronic toxicity, 0105 earth and related environmental sciences, Chironomus riparius, Analysis of Variance, Life Cycle Stages, 021110 strategic, defence & security studies, Larva, ved/biology, Public Health, Environmental and Occupational Health, Neonicotinoid, General Medicine, Nitro Compounds, Invertebrates, Pollution, language.human_language, Thiazoles, chemistry, Toxicity, language, Thiamethoxam, Water Pollutants, Chemical
Abstract

The insecticide thiamethoxam (TMX) is a systemic neonicotinoid widely used for pest control in several agricultural crops. TMX mimics the action of acetylcholine causing uncontrolled muscular contraction eventually leading to insect death. TMX is being found in freshwater ecosystems at concentrations of up to 225µg/L. Still, chronic toxicity data for freshwater invertebrates is limited. Therefore, the aim of this study was to evaluate the acute and chronic effects (at organismal and biochemical levels) of TMX on the freshwater insect Chironomus riparius. C. riparius life history responses were significantly affected by TMX exposure, namely with a decrease in growth and delay in emergence. Concerning the biochemical responses, after a short exposure (48h) to TMX, our results showed that low concentrations of TMX significantly reduced CAT activity and LPO levels of C. riparius. No effects were observed in AChE, GST and ETS activities. Effects in terms of survival, development rates and biochemical responses of C. riparius exposed to low concentrations of TMX observed in this study suggest potential deleterious effects of this neonicotinoid on aquatic insects inhabiting freshwaters environments near agricultural areas.

Published
2017
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