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| Main Authors: | , , , , , , |
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| Format: | Artículo científico |
| Language: | en |
| Published: |
Environmental science & technology
2025
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| Subjects: | |
| Online Access: | https://pubmed.ncbi.nlm.nih.gov/41328925/ |
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Table of Contents:
- Contrasting Size Dependence of Photochemical Lifetimes of Polypropylene and Expanded Polystyrene Microplastics in Surface Waters. Patterson, Ariana Wiman, Charlotte Muñoz, Samuel Tuttle, Erin Zhu, Lixin Law, Kara Lavender Stubbins, Aron Polystyrenes Polypropylenes Microplastics Water Pollutants, Chemical Particle Size Photochemical Processes Sunlight Microplastics are found floating on natural waters. Sunlight-driven photochemistry can dissolve buoyant microplastics, producing dissolved organic carbon (DOC). We hypothesized that plastic dissolution would increase linearly with increasing surface area (SA)-to-volume (V) ratio as plastics decrease in size. To test this, samples of expanded polystyrene (EPS) and polypropylene (PP) spanning a range of sizes were irradiated while floating on water in a solar simulator. A linear relationship between SA:V and DOC accumulation rate was significant for EPS ( < 0.0001) and PP ( = 0.0086), suggesting SA-controlled reactions. However, a power relationship with an exponent of approximately 0.5 between PP dissolution and SA:V provided a significantly better fit, suggesting that non-SA-controlled processes may limit PP photodissolution. Using these relationships, it was estimated that macroplastics ∼10 cm should take ∼250 to ∼8000 years to photochemically dissolve. However, estimated lifetimes are shorter for smaller plastics, with 1 mm EPS beads and 100 nm PP nanoplastics estimated to have lifetimes of 5.3 years and 3 to 196 days, respectively, with the range in lifetimes for PP dependent upon whether linear or power fits are applied.