This upsurge is linked to the kind and amount of plastic products that society consumes. This revelation comes from a study conducted by the Department of the Built Environment of Aalborg University (AAU-BUILD) and the Institute of Environmental Science and Technology of the Universitat Autnoma de Barcelona (ICTA-UAB), which offers an initial high-resolution reconstruction of microplastic pollution from sediments taken from the northwestern Mediterranean Sea.
The historical evolution of the pollution source of microplastics in the sediment compartment, particularly the rate of sequestration and burial on the ocean floor, remains unknown despite the fact that the seafloor is thought to be the final destination for microplastics floating on the surface of the water. A study recently published in the journal Environmental Science and Technology (ES&T) has revealed that these microplastics are retained unchanged in marine sediments, and that the quantity of microplastics trapped in the seafloor corresponds to the aggregate amount of plastic produced globally between 1965 and 2016. ICTA-UAB researcher Laura Simon-Sánchez commented, "Our findings demonstrate that the amount of plastic particles deposited on the seafloor has tripled since 2000, and that the accumulation has not ceased to grow in parallel with the manufacture and worldwide utilization of these materials."
Researchers have elucidated that since they were deposited on the seafloor many years ago, the sediments under examination have remained immutable. This has enabled us to detect how the quantity of polyethylene, polypropylene particles from packaging, containers, and food films, in addition to polyester from synthetic fibers in clothing fabrics, has risen since the 1980s, particularly in the past two decades," stated Michael Grelaud, a researcher from ICTA-UAB, as per ScienceDaily.
The total sum of these three particle types is 1.5 mg per kilogram of sediment collected, with polypropylene being the most common and polyethylene, polyester, and other materials coming in second and third.
Data from yearly marine sediment statistics suggest that we are still a long way from achieving this despite awareness campaigns on the need to reduce single-use plastic.
Although smaller microplastics are omnipresent in the environment, limitations in analytical techniques have hindered prior studies that targeted marine sediment from providing solid evidence about the levels of minuscule microplastics.
In this study, they were identified by utilizing state-of-the-art imaging to quantify particles as little as 11 nanometers.
Are people and marine life both at risk of experiencing health issues due to the presence of microplastics in the marine environment? It is widely known that larger plastic objects can cause serious harm to marine life, such as dolphins getting caught in fishing gear or sea turtles trapped in plastic six-pack rings, as mentioned by WHOI. However, the effects of microplastics on human health are largely unknown.
Marine organisms at the bottom of the food chain, such as plankton and fish larvae, as well as filter-feeding creatures humans consume, like oysters and scallops, are known to ingest microplastics. This poses a potential risk as microplastics may contain hazardous substances used in the manufacturing process, such as phthalates, bisphenol A, and others. Additionally, toxic substances like polychlorinated biphenyls (PCBs), which are linked to cancer and other serious health issues, can be absorbed by plastics from the environment.
To assess the potential health risks to marine life and humans, scientists are identifying which types of microplastics appear to be the most hazardous and how much of them are being ingested by marine life and humans.