Papers

61,005 results
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Article Tier 2

Size-dependent chronic toxicity of fragmented polyethylene microplastics to Daphnia magna

Researchers tested the long-term effects of irregularly shaped polyethylene microplastic fragments on the freshwater organism Daphnia magna over 21 days. They found that fragmented microplastics were ingested at much higher rates and caused more harm to reproduction and survival than smooth, round plastic beads of similar size, suggesting particle shape matters for toxicity.

2021 Chemosphere 193 citations
Article Tier 2

Assessing the acute differential toxicity of polystyrene microplastic particles and comparing the impacts of bead-shaped versus fragmented particles on Daphnia magna

Researchers compared the toxicity of polystyrene microplastic fragments versus beads on tiny freshwater crustaceans (Daphnia magna) and found that jagged fragments were more harmful than smooth beads, causing greater mortality and triggering more stress-related genes — suggesting that the shape of a microplastic particle matters as much as its chemical makeup.

2025 Applied Biological Chemistry 3 citations
Article Tier 2

Nanoplastics induce more severe multigenerational life-history trait changes and metabolic responses in marine rotifer Brachionus plicatilis: Comparison with microplastics

Researchers compared the effects of nanoplastics versus microplastics on marine rotifers across multiple generations. They found that smaller nanoplastics (70 nm) caused significantly more severe harm to population growth, lifespan, and reproduction than larger particles, with negative effects persisting across generations. The study suggests that nanoplastics may pose a greater long-term threat to marine organisms than microplastics due to their ability to disrupt metabolism and nutrient accumulation.

2023 Journal of Hazardous Materials 39 citations
Article Tier 2

Size- and shape-dependent ingestion and acute toxicity of fragmented and spherical microplastics in the absence and presence of prey on two marine zooplankton

Researchers tested how the size and shape of microplastics affect their toxicity to tiny marine animals called zooplankton. Smaller particles were swallowed more often, but irregularly shaped fragments were more toxic than smooth spheres of similar size. When natural food was present, the animals ate fewer microplastics, suggesting that real-world toxicity depends on both particle characteristics and environmental conditions.

2024 Marine Pollution Bulletin 27 citations
Article Tier 2

Chronic effects of irregular and fibril microplastics on Artemia franciscana in a benthic environment: Size and shape-dependent toxicity

Researchers studied how irregular and fibril-shaped microplastics of various sizes affect brine shrimp in a simulated seafloor environment over an extended period. They found that the smallest irregular particles and longer fibers caused the most significant reproductive and growth effects. The study demonstrates that both the size and shape of microplastics matter when assessing their impact on bottom-dwelling marine organisms.

2024 Marine Pollution Bulletin 9 citations
Article Tier 2

Shape-driven toxicity of polystyrene microplastics: Impacts on physiology and gut microbiota in Daphnia magna

Researchers studied how the shape of polystyrene microplastics affects toxicity in the water flea Daphnia magna, comparing irregular fragments to smooth beads. The study found that fragment-shaped microplastics were more toxic than spherical beads, triggered stronger reactive oxygen species production, and induced different gut microbiota changes, suggesting that particle shape is an important factor in microplastic toxicity.

2026 Marine Pollution Bulletin
Article Tier 2

Microplastic Size-Dependent Toxicity, Oxidative Stress Induction, and p-JNK and p-p38 Activation in the Monogonont Rotifer (Brachionus koreanus)

Researchers tested the effects of different sizes of polystyrene microbeads on a type of microscopic aquatic animal called a rotifer. They found that the smallest particles caused the most harm, reducing growth rate and reproduction while triggering oxidative stress and activating cellular defense pathways. The study demonstrates that microplastic toxicity increases as particle size decreases, suggesting nanoplastics may pose greater biological risks than larger fragments.

2016 Environmental Science & Technology 1172 citations
Article Tier 2

Metabolism deficiency and oxidative stress induced by plastic particles in the rotifer Brachionus plicatilis: Common and distinct phenotypic and transcriptomic responses to nano- and microplastics

Researchers found that nanoplastics caused stronger reproductive and population growth inhibition in the marine rotifer Brachionus plicatilis than microplastics, with transcriptomic analysis revealing distinct size-dependent toxicity pathways involving metabolism deficiency and oxidative stress.

2022 Marine Pollution Bulletin 24 citations
Article Tier 2

Variable Fitness Response of Two Rotifer Species Exposed to Microplastics Particles: The Role of Food Quantity and Quality

This study examined how different sizes and types of microplastics affect two rotifer species, which are small aquatic animals important to freshwater food webs. The effects varied depending on the particle size, shape, and the amount and quality of food available to the rotifers. The findings show that the impact of microplastics on aquatic organisms depends heavily on environmental context, making risk assessment complex.

2021 Toxics 12 citations
Article Tier 2

Evaluation of the hazard of irregularly-shaped co-polyamide microplastics on the freshwater non-biting midge Chironomus riparius through its life cycle

Laboratory experiments exposed the freshwater midge Chironomus riparius to irregularly shaped co-polyamide microplastics across its full life cycle, finding effects on survival, development, and reproduction at environmentally relevant concentrations. The study highlights that real-world plastic shapes and polymers, not just the smooth spheres commonly used in tests, can harm freshwater invertebrates.

2019 Chemosphere 58 citations
Article Tier 2

Microplastics but not natural particles induce multigenerational effects in Daphnia magna

Daphnia magna were exposed to irregular polyethylene microplastics across multiple generations and compared to naturally occurring mineral particles of similar size; microplastics caused multigenerational reductions in reproduction and body size while natural particles did not, demonstrating particle-type-specific chronic effects.

2019 Environmental Pollution 139 citations
Article Tier 2

Toxic effects of fragmented polyethylene terephthalate particles on the marine rotifer Brachionus koreanus: Based on ingestion and egestion assay, in vivo toxicity test, and multi-omics analysis

Scientists tested the effects of fragmented PET microplastics, one of the most common types found in the ocean, on tiny marine organisms called rotifers. While the microplastics did not directly kill the rotifers, they increased oxidative stress and disrupted energy metabolism and immune-related genes. Since rotifers are at the base of the marine food chain, damage to these organisms could have ripple effects that eventually reach humans through seafood.

2024 Journal of Hazardous Materials 11 citations
Article Tier 2

Statistical Curvature Change Analysis of Random-Shape Polyethylene Microplastics and their Toxicity from a Physical Perspective

This study examined how the physical shape of polyethylene microplastics affects their toxicity to cells in laboratory experiments. Irregularly shaped fragments caused more cellular damage than smooth spheres, suggesting that the jagged surfaces of environmentally weathered microplastics may be particularly hazardous.

2020 Research Square (Research Square) 2 citations
Article Tier 2

Shape, size, and polymer dependent effects of microplastics on Daphnia magna

Researchers systematically tested how the shape, size, and material of microplastic particles affect the water flea Daphnia magna by comparing polystyrene particles to non-plastic control particles with similar properties. They found that small polystyrene beads and fragments caused harmful effects on reproduction and body shape, while none of the non-plastic control particles caused any damage. The study suggests that the toxic effects are specific to the plastic polymer itself, not simply a result of ingesting small particles.

2021 Journal of Hazardous Materials 166 citations
Article Tier 2

In vitro toxicity from a physical perspective of polyethylene microplastics based on statistical curvature change analysis

Researchers investigated the in vitro toxicity of polyethylene microplastics of two different shapes using statistical analysis of particle curvature. They found that irregularly shaped microplastic fragments caused greater cellular damage than more uniformly shaped particles, suggesting that physical characteristics beyond size influence toxicity. The study demonstrates that the sharp edges and irregular surfaces of environmentally degraded microplastics may contribute to their harmful biological effects.

2020 The Science of The Total Environment 182 citations
Article Tier 2

Insights into the shape-dependent effects of polyethylene microplastics on interactions with organisms, environmental aging, and adsorption properties

Researchers tested how the shape of polyethylene microplastics, whether spheres, fragments, or films, affects their environmental behavior and toxicity. Fragment-shaped particles stuck to plant roots and reduced root growth, while film-shaped particles absorbed twice as much chemical contamination as spheres and fragments. These findings show that microplastic shape matters significantly for both ecological impact and how much pollution they can carry, meaning that real-world irregularly shaped microplastics may behave very differently from the uniform spheres commonly used in lab studies.

2023 Scientific Reports 49 citations
Article Tier 2

Size matters more than shape: Ingestion of primary and secondary microplastics by small predators

Researchers offered irregularly shaped secondary microplastics — fragments more realistic than the perfect spheres used in most lab studies — to small fish and shrimp at natural concentrations, finding that particle size was a stronger predictor of ingestion than shape. The study underscores that lab results using uniform plastic beads may overestimate real-world microplastic uptake in marine food webs.

2018 Food Webs 351 citations
Article Tier 2

Size over substance: Microplastic particle size drives gene expression and fitness loss in a freshwater insect

Researchers exposed freshwater midge larvae to polyamide and polyvinyl chloride microplastics of different sizes and found that particle size mattered more than plastic type in determining harm. Smaller microplastics triggered stronger stress responses at the gene level, including oxidative stress and immune activation, and caused greater reductions in reproduction and survival. The findings suggest that size should be a primary consideration when assessing microplastic risks to aquatic life.

2025 Aquatic Toxicology 4 citations
Article Tier 2

A fit-for-purpose categorization scheme for microplastic morphologies

Researchers studied the long-term effects of polypropylene microplastic exposure on the life history traits of the water flea Daphnia magna across three generations, finding progressively increasing reproductive impairment and reduced survival in successive generations. The multigenerational impacts exceeded those observed in single-generation tests.

2022 Integrated Environmental Assessment and Management 18 citations
Article Tier 2

Toxicological effects of irregularly shaped and spherical microplastics in a marine teleost, the sheepshead minnow (Cyprinodon variegatus)

Researchers compared the toxicological effects of irregularly shaped versus spherical microplastics on sheepshead minnows. Both types accumulated in the digestive system and caused intestinal distention, but irregularly shaped particles were more harmful, reducing swimming behavior more than spherical ones. The study highlights that the shape of microplastic particles matters for toxicity assessments, and commonly used uniform spheres may underestimate real-world risks.

2018 Marine Pollution Bulletin 383 citations
Article Tier 2

Size- and shape-dependent effects of polyethylene terephthalate microplastics on the benthic crustacean Artemia franciscana

Researchers tested how different sizes and shapes of PET microplastics affect juvenile brine shrimp in a sand-layered system simulating the ocean floor. Small fragments that could be ingested caused gut damage and impaired movement, while larger fragments and fibers triggered cell death through physical stress. The findings indicate that the shape and size of microplastics are major factors in determining their harmful effects on bottom-dwelling marine organisms.

2024 Marine Pollution Bulletin 6 citations
Article Tier 2

Small-Sized Microplastics Negatively Affect Rotifers: Changes in the Key Life-History Traits and Rotifer–Phaeocystis Population Dynamics

Researchers found that small-sized microplastics negatively affected rotifer survival, reproduction, and feeding rates, and also disrupted the population dynamics of rotifers interacting with the harmful alga Phaeocystis in coastal water microcosms.

2019 Environmental Science & Technology 114 citations
Article Tier 2

Effect of microplastics on the demography of Brachionus calyciflorus Pallas (Rotifera) over successive generations

Researchers examined how microplastic exposure affects the population dynamics of a freshwater rotifer species across two successive generations. They found that microplastics reduced reproduction rates and lifespan, with effects carrying over into the second generation even when exposure was removed. The study suggests that microplastic pollution may have lasting population-level consequences for small aquatic organisms.

2024 Aquatic Toxicology 5 citations
Article Tier 2

Metabolic responses of the marine mussel Mytilus galloprovincialis after exposure to microplastics of different shapes and sizes

Researchers exposed Mediterranean mussels to microplastics of different shapes and sizes and found that round particles and small fibers accumulated the most in mussel tissues. These same particle types caused the most significant metabolic changes, altering amino acid processing and vitamin pathways. The findings suggest that the shape and size of microplastics play an important role in determining how much harm they cause to marine filter-feeding organisms.

2024 Environmental Pollution 8 citations