Validation of ATR FT-IR to identify polymers of plastic marine debris, including those ingested by marine organisms.

Although microplastics are known to pervade the global seafloor, the processes that control their dispersal and concentration in the deep sea remain largely unknown. Here, we show that thermohaline-driven currents, which build extensive seafloor sediment accumulations, can control the distribution of microplastics and create hotspots with the highest concentrations reported for any seafloor setting (190 pieces per 50 grams). Previous studies propose that microplastics are transported to the seafloor by vertical settling from surface accumulations; here, we demonstrate that the spatial distribution and ultimate fate of microplastics are strongly controlled by near-bed thermohaline currents (bottom currents). These currents are known to supply oxygen and nutrients to deep-sea benthos, suggesting that deep-sea biodiversity hotspots are also likely to be microplastic hotspots.

https://science.sciencemag.org/content/sci/early/2020/04/29/science.aba5899.full.pdf

Seafloor microplastic hotspots controlled by deep-sea circulation.

Whereas the dramatic environmental impact of plastic waste rightfully receives considerable attention by scientists, policy makers and public in general, the human health impact of micro- and nanoplastics contamination of our food and beverages remains largely unknown. Indeed, most studies aim at understanding the environmental impact rather than the human health impact of a possible exposure to micro- and nanoplastics. In addition, these papers generally lack a methodological, standardised approach. Furthermore, some studies focus on the damage to and contamination level of animal species collected from the wild environment, and others investigate the rate and biology of microplastic uptake of animals fed with microplastics in laboratory. This review aims at understanding human exposure. Since there is, with few exceptions, no evidence available on the presence of micro- and nanoplastics in a normal diet, this study takes an indirect approach and analyses peer-reviewed publications since 2010 that document the presence of micro- and nanoplastics in those animals (more than 200 species) and food products that are part of the human food chain and that may thus contribute directly or indirectly to the uptake of micro- and nanoplastics via the human diet. It also addresses the question of the definitions, the methodologies and the quality criteria applied to obtain the reported results. This review suggests that, beyond a few estimations and comparisons, precise data to assess the exact exposure of humans to micro- and nanoplastics through their diet cannot be produced until standardised methods and definitions are available.

https://tandfonline.com/doi/pdf/10.1080/19440049.2019.1583381

Review of micro- and nanoplastic contamination in the food chain

Plastics entering the environment will persist and continue to degrade and fragment to smaller particles under the action of various environmental factors. These microplastics (MP) and nanoplastics (NP) are likely to pose a higher environmental impact, as well as they are more prone to adsorb organic contaminants and pathogens from the surrounding media, due to their higher surface area to volume ratio. Little known on their characteristics, fragmentation, distribution and impact on freshwater ecosystems. In order to respond to these open questions concerning the plastic particles dynamics and their environmental effects, detailed sampling strategies as well as an automated, rapid, cheap and reliable analytical technique suitable for routine analysis need to be developed. The review outlines the recent advances made on examination of the potential toxicological effects of MP and NP on freshwater biota, as well as the available analytical methods employed to identify and quantify them in environmental samples.

Micro- (nano) plastics in freshwater ecosystems: Abundance, toxicological impact and quantification methodology

Microplastics along the beaches of southeast coast of India.

Polymeric differences of plastic debris were assessed across four compartments of the Main Hawaiian Islands (sea surface, windward beaches, leeward beaches, and seafloor) to better describe sources and fate. Plastic debris pieces (n = 4671) were collected from 11 beaches, three sea surface tows, and three seafloor dives. Fourier transform infrared spectroscopy identified the polymers of 3551 pieces. Significant differences (p < 0.05) in concentration, types, polymer composition, and weathering were found among four compartments. Windward beaches had 1-2 orders of magnitude more plastic pollution (g/m2) than leeward beaches, despite smaller human populations on windward sides. Sea surface and windward beaches were dominated by severely weathered, less dense floating polymers (polyethylene and polypropylene comprised 92.7 and 93.5% on average, respectively, of the total debris mass), while leeward beaches and the seafloor debris consisted of less weathered and more dense sinking polymers (e.g., 41.0 and 44.7% of total mass consisted of the sum of polystyrene, nylon, cellulose acetate, polyethylene terephthalate, and additive-masked debris). These results are some of the first to provide evidence of polymeric stratification in the marine environment and emphasize that the majority of marine debris in Hawaii is floating in from distant sources rather than from Hawaii's residents or tourists.

Marine Debris Polymers on Main Hawaiian Island Beaches, Sea Surface, and Seafloor.

Pelagic Pacific sea turtles eat relatively large quantities of plastic (median 5 g in gut). Using Fourier transform infrared spectroscopy, we identified the polymers ingested by 37 olive ridley, 9 ...

Melissa R Jung

Papers

Validation of ATR FT-IR to identify polymers of plastic marine debris, including those ingested by marine organisms.

Marine Debris Polymers on Main Hawaiian Island Beaches, Sea Surface, and Seafloor.

Polymer Identification of Plastic Debris Ingested by Pelagic-Phase Sea Turtles in the Central Pacific.