Mapping Plastic and Plastic Additive Cycles in Coastal Countries: A Norwegian Case Study

The growing environmental consequences caused by plastic pollution highlight the need for a better understanding of plastic polymer cycles and their associated additives. We present a novel, comprehensive top-down method using inflow-driven dynamic probabilistic material flow analysis (DPMFA) to map the plastic cycle in coastal countries. For the first time, we covered the progressive leaching of microplastics to the environment during the use phase of products and modeled the presence of 232 plastic additives. We applied this methodology to Norway and proposed initial release pathways to different environmental compartments. 758 kt of plastics distributed among 13 different polymers was introduced to the Norwegian economy in 2020, 4.4 Mt was present in in-use stocks, and 632 kt was wasted, of which 15.2 kt (2.4%) was released to the environment with a similar share of macro- and microplastics and 4.8 kt ended up in the ocean. Our study shows tire wear rubber as a highly pollutive microplastic source, while most macroplastics originated from consumer packaging with LDPE, PP, and PET as dominant polymers. Additionally, 75 kt of plastic additives was potentially released to the environment alongside these polymers. We emphasize that upstream measures, such as consumption reduction and changes in product design, would result in the most positive impact for limiting plastic pollution.

Sea of plastic: representations of the sea and pro-environmental attitudes and behaviors regarding marine plastic pollution in Peru and Chile

Marine plastic pollution remains one of the greatest problems worldwide. Hence, this study explores the attitudes and pro-environmental behaviors of Peruvian and Chilean citizens regarding marine pollution, with an emphasis on plastic pollution. For this, forty-four semi-structured interviews were conducted with Peruvian (n = 24) and Chilean (n = 20) citizens, of which, through thematic analysis, semantic patterns were identified. Results show that the participants' representation of the sea is positive and related to the connection they report having with this environment. Additionally, it was found that the sea fulfills recreational and economic purposes, reflecting an anthropocentric perspective, since it is associated with leisure and resource extraction, respectively. Both purposes are related to the causes of plastic pollution, although with differentiated effects. Anthropocentrism is also reflected in the direction that environmental concern takes towards the impact of this type of pollution predominately on individuals and society. Regarding pro-environmental behaviors, most of the initiatives proposed by the participants in response to marine plastic pollution correspond to individual actions, which could be due to the fact that they perceive a low commitment level from authorities to address the problem. In particular, the Chilean participants attributed a greater role to their authorities in dealing with plastic pollution, which would indicate a more institutional perspective of the problem. Thus, it is proposed that to address marine plastic pollution it is necessary to articulate individual actions with public policies carried out by social stakeholders such as governments, companies and non-governmental organizations, in order to build a more efficient culture of marine protection.

Seawater-Degradable Polymers-Fighting the Marine Plastic Pollution

Polymers shape human life but they also have been identified as pollutants in the oceans due to their long lifetime and low degradability. Recently, various researchers have studied the impact of (micro)plastics on marine life, biodiversity, and potential toxicity. Even if the consequences are still heavily discussed, prevention of unnecessary waste is desired. Especially, newly designed polymers that degrade in seawater are discussed as potential alternatives to commodity polymers in certain applications. Biodegradable polymers that degrade in vivo (used for biomedical applications) or during composting often exhibit too slow degradation rates in seawater. To date, no comprehensive summary for the degradation performance of polymers in seawater has been reported, nor are the studies for seawater-degradation following uniform standards. This review summarizes concepts, mechanisms, and other factors affecting the degradation process in seawater of several biodegradable polymers or polymer blends. As most of such materials cannot degrade or degrade too slowly, strategies and innovative routes for the preparation of seawater-degradable polymers with rapid degradation in natural environments are reviewed. It is believed that this selection will help to further understand and drive the development of seawater-degradable polymers.

Rapid aggregation of biofilm-covered microplastics with marine biogenic particles

Ocean plastic pollution has resulted in a substantial accumulation of microplastics in the marine environment. Today, this plastic litter is ubiquitous in the oceans, including even remote habitats such as deep-sea sediments and polar sea ice, and it is believed to pose a threat to ecosystem health. However, the concentration of microplastics in the surface layer of the oceans is considerably lower than expected, given the ongoing replenishment of microplastics and the tendency of many plastic types to float. It has been hypothesized that microplastics leave the upper ocean by aggregation and subsequent sedimentation. We tested this hypothesis by investigating the interactions of microplastics with marine biogenic particles collected in the southwestern Baltic Sea. Our laboratory experiments revealed a large potential of microplastics to rapidly coagulate with biogenic particles, which substantiates this hypothesis. Together with the biogenic particles, the microplastics efficiently formed pronounced aggregates within a few days. The aggregation of microplastics and biogenic particles was significantly accelerated by microbial biofilms that had formed on the plastic surfaces. We assume that the demonstrated aggregation behaviour facilitates the export of microplastics from the surface layer of the oceans and plays an important role in the redistribution of microplastics in the oceans.