Microplastics deposited on the seafloor have tripled in 20 years
< Science and Technology Daily intern reporter Zhang Jiaxin
The total amount of microplastics deposited on the seafloor has tripled in the past 20 years, and the amount corresponds to the type and amount of plastic products consumed. This is the main conclusion of a study carried out by the Institute of Environmental Science and Technology at the University of Barcelona in Spain and the Department of the built Environment at Aalborg University in Denmark, which for the first time reconstructed microplastic pollution from sediments in the northwestern Mediterranean Sea in high resolution.
Although the seafloor is considered to be the ultimate sedimentation tank for microplastics floating on the surface, the historical evolution of this source of pollution on the seafloor, in particular the rate of sequestration and burial of smaller microplastics on the seafloor, is unclear.
The new study, published recently in the journal Environmental Science & Technology, shows that microplastics remain constant in Marine sediments, and that the quality of these microplastics mimics global plastic production from 1965 to 2016.
The researchers investigated the degradation status of the buried particles by applying state-of-the-art imaging techniques to quantify particles with a size of 11 micrometers. They found that once the microplastics were trapped on the seafloor, they no longer degraded.
Research shows that the number of plastic particles deposited on the seafloor has tripled since 2000, and that the cumulative number of plastic particles has been growing with the production and global use of these materials.
The accumulation of polyethylene and polypropylene particles in packaging, bottles and food films, as well as polyester particles in synthetic fibers in clothing fabrics, has been increasing over the past 20 years, the researchers explain. Each of the three particles reached 1.5 milligrams per kilogram of sediment collected, with polypropylene having the highest concentration, followed by polyethylene and polyester.