We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Comparative long-term studies on the degradation of environmental microplastics under different abiotic conditions in a marine in situ laboratory
AI summary Read the abstract
Researchers conducted a 29-year study of plastic degradation using resin pellets from a shipwreck off Egypt, comparing plastics that had been exposed to beach conditions versus open-ocean conditions over nearly three decades. The results showed significant physical and chemical degradation under beach conditions while ocean-submerged plastics remained more intact, helping constrain realistic estimates of how long microplastic precursors persist in different marine environments.
Once discarded into marine environments, plastics start to degrade until complete mineralization. For polyethylene, it is estimated that this process takes about 1.4 to 1,500 years. The high uncertainty comes from the lack of long-term investigations under environmentally relevant conditions, as information on the age of environmental plastics is typically not available. One exceptional case are microplastic resin pellets from the SS Hamada, whose age is exactly dated by the day of foundering twenty-nine years ago in the Wadi el Gemal national park, Egypt. Its plastic load made of low-density polyethylene ended up in two in situ laboratories: a beach, characterized by high temperatures, heavy UV radiation, waves, and tidal range, plus the dark and cold saltwater inside the cargo holds at 18 meters depth. For these very different sample sites, the status quo of plastic degradation was comparatively assessed by imaging, chemical, and rheological methods. We found that even after nearly three decades, microplastics in the Red Sea were in a pristine-like state, whereas microplastics on the beach have been degraded on all structural levels. In particular, a distinct crack network, an increased number of carbonyl groups, cross-linking of chain branches, a higher crystallinity, and an altered rheological behavior was observed, all of which resulted in fragmentation. Altogether, this proves that plastic degradation is considerably slower in the ocean compared to beaches. Here, photochemical and thermo-oxidative weathering accelerate the degradation as a consequence of the abiotic conditions, which the beached microplastic resin pellets from the SS Hamada have to face. With this study object on hand, future monitoring should enable the calibration of existing models to derive robust estimates for degradation rates of plastics in different marine environments. Also see: https://micro2022.sciencesconf.org/426906/document
More Papers Like This
In situ laboratory for plastic degradation in the Red Sea
AI summary Read the abstract
Researchers used microplastic pellets from a ship that sank 29 years ago as a natural laboratory to study how plastics degrade over time, finding that pellets submerged in saltwater showed almost no degradation while beach-exposed pellets broke down significantly. This confirms that UV sunlight and heat — not saltwater — are the main drivers of plastic fragmentation into smaller and smaller particles.
Long-term aging and degradation of microplastic particles: Comparing in situ oceanic and experimental weathering patterns
AI summary Read the abstract
Researchers weathered polypropylene and polyethylene pellets in sunlight and seawater for three years and compared chemical bond changes via FTIR spectroscopy to particles collected from North Pacific ocean gyres, estimating that most gyre plastics have been at sea for more than 18 months — consistent with ocean circulation residence-time models.
An advanced analytical approach to assess the long-term degradation of microplastics in the marine environment
AI summary Read the abstract
Researchers exposed several types of plastic pellets to realistic ocean conditions over time and found that marine weathering caused much faster surface degradation than previously estimated — up to 469 micrometers per year, twelve times higher than older figures — while also generating secondary micro- and nanoplastic particles smaller than one micron. The results provide critical real-world data for assessing how quickly ocean plastics break down into even tinier, harder-to-detect fragments.
An In Situ Experiment to Evaluate the Aging and Degradation Phenomena Induced by Marine Environment Conditions on Commercial Plastic Granules
AI summary Read the abstract
Researchers designed two experimental setups to monitor the aging and degradation of commercial plastic granules (HDPE, PP, PLA, and PBAT) in marine conditions over three years. The first six months of results showed measurable changes in plastic properties from exposure to seawater and beach conditions. The study provides real-world data on how different plastic types degrade in marine environments, with biodegradable plastics showing faster changes than conventional polymers.
Simulated experimental investigation of microplastic weathering in marine environment
AI summary Read the abstract
Researchers simulated microplastic weathering under marine conditions, finding that exposure to UV light, saltwater, and mechanical abrasion progressively degraded plastic surfaces, increased surface roughness, and enhanced the adsorption capacity of contaminants onto microplastic particles.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.