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28-12-2022, 07:06 PM
Noticias:
Microplastics on the seabed have tripled in 20 years.
This is a progression that corresponds to the type and volume of consumption of plastic products by society
Francisco Martin Leon
This is the main conclusion of a study developed by the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) and the Department of Built Environment of the University of Aalborg (AAU-BUILD), which provides the first high
Despite the fact that the seafloor is considered the final sink of microplastics floating on the sea surface, the historical evolution of this source of pollution in the sediment compartment and, in particular, the rate of sequestration and burial of smaller microplastics on the ocean floor is unknown.
This new study, published in the journal Environmental Science and Technology, shows that microplastics are retained unchanged in marine sediments and that the mass of microplastics sequestered on the seafloor mimics global plastic production between 1965 and 2016. "Specifically, the results show that, since 2000, the amount of plastic particles deposited on the seabed has tripled and that, far from decreasing, the accumulation has not stopped growing, mimicking the production and global use of these materials," explains ICTA-UAB, researcher Laura Simón-Sánchez.
The researchers explain that the analyzed sediments have remained unchanged on the seafloor since they were deposited decades ago. "This has allowed us to see how, since the 1980s, but especially in the last two decades, the accumulation of polyethylene and polypropylene particles from food containers, bottles and films, as well as polyester from synthetic fibers in garment fabrics, has increased," explains Michael Grelaud, ICTA-UAB researcher. The amount of these three types of particles reaches 1.5 mg per kilogram of sediment collected, with polypropylene being the most abundant, followed by polyethylene and polyester.
Despite awareness campaigns on the need to reduce single-use plastic, data from annual marine sediment records show that we are still far from achieving this. Global policies in this regard could help to improve this serious problem. Although smaller microplastics are very abundant in the environment, restrictions on analytical methods have limited solid evidence on levels of small microplastics in previous studies targeting marine sediments.
In this study, they were characterized by applying state-of-the-art imaging to quantify particles up to 11 μm in size. The state of degradation of the buried particles was investigated and it was found that, once trapped on the seabed, they no longer degrade, either due to lack of erosion, oxygen or light. "The fragmentation process occurs mostly in the sediments of the beach, on the surface of the sea or in the water column. Once deposited, the degradation is minimal, so the plastics of the 1960s remain on the seabed, leaving there the signature of human pollution," says Patrizia Ziveri, ICREA professor at ICTA-UAB.
The sediment core investigated was collected in November 2019, aboard the oceanographic vessel Sarmiento de Gamboa, in an expedition that went from Barcelona to the coast of the Ebro Delta, in Tarragona, Spain. The research group selected the western Mediterranean Sea as a study area, particularly the Ebro Delta, because rivers are recognized as hotspots for several pollutants, including microplastics. In addition, the sediment inflow of the Ebro River provides higher sedimentation rates than in the open sea.
Reference
Laura Simon-Sánchez et al, Can a Sediment Core Reveal the Plastic Age? Microplastic Preservation in a Coastal Sedimentary Record. Environmental Science & Technology (2022). DOI: 10.1021/acs.est.2c04264
Microplastics on the seabed have tripled in 20 years.
This is a progression that corresponds to the type and volume of consumption of plastic products by society
Francisco Martin Leon
This is the main conclusion of a study developed by the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) and the Department of Built Environment of the University of Aalborg (AAU-BUILD), which provides the first high
Despite the fact that the seafloor is considered the final sink of microplastics floating on the sea surface, the historical evolution of this source of pollution in the sediment compartment and, in particular, the rate of sequestration and burial of smaller microplastics on the ocean floor is unknown.
This new study, published in the journal Environmental Science and Technology, shows that microplastics are retained unchanged in marine sediments and that the mass of microplastics sequestered on the seafloor mimics global plastic production between 1965 and 2016. "Specifically, the results show that, since 2000, the amount of plastic particles deposited on the seabed has tripled and that, far from decreasing, the accumulation has not stopped growing, mimicking the production and global use of these materials," explains ICTA-UAB, researcher Laura Simón-Sánchez.
The researchers explain that the analyzed sediments have remained unchanged on the seafloor since they were deposited decades ago. "This has allowed us to see how, since the 1980s, but especially in the last two decades, the accumulation of polyethylene and polypropylene particles from food containers, bottles and films, as well as polyester from synthetic fibers in garment fabrics, has increased," explains Michael Grelaud, ICTA-UAB researcher. The amount of these three types of particles reaches 1.5 mg per kilogram of sediment collected, with polypropylene being the most abundant, followed by polyethylene and polyester.
Despite awareness campaigns on the need to reduce single-use plastic, data from annual marine sediment records show that we are still far from achieving this. Global policies in this regard could help to improve this serious problem. Although smaller microplastics are very abundant in the environment, restrictions on analytical methods have limited solid evidence on levels of small microplastics in previous studies targeting marine sediments.
In this study, they were characterized by applying state-of-the-art imaging to quantify particles up to 11 μm in size. The state of degradation of the buried particles was investigated and it was found that, once trapped on the seabed, they no longer degrade, either due to lack of erosion, oxygen or light. "The fragmentation process occurs mostly in the sediments of the beach, on the surface of the sea or in the water column. Once deposited, the degradation is minimal, so the plastics of the 1960s remain on the seabed, leaving there the signature of human pollution," says Patrizia Ziveri, ICREA professor at ICTA-UAB.
The sediment core investigated was collected in November 2019, aboard the oceanographic vessel Sarmiento de Gamboa, in an expedition that went from Barcelona to the coast of the Ebro Delta, in Tarragona, Spain. The research group selected the western Mediterranean Sea as a study area, particularly the Ebro Delta, because rivers are recognized as hotspots for several pollutants, including microplastics. In addition, the sediment inflow of the Ebro River provides higher sedimentation rates than in the open sea.
Reference
Laura Simon-Sánchez et al, Can a Sediment Core Reveal the Plastic Age? Microplastic Preservation in a Coastal Sedimentary Record. Environmental Science & Technology (2022). DOI: 10.1021/acs.est.2c04264
