The effectiveness of legislative and voluntary strategies to prevent ocean plastic pollution: Lessons from the UK and South Pacific

Embracing epistemic uncertainty: a risk evaluation method for pollutants in stormwater

In this study, we show that pollutants of emerging concern are, by nature, prone to the emergence of epistemic uncertainty. We also show that the current uncertainty quantification methods used for pollutant modelling rely almost exclusively on parameter uncertainty, which is not adequate to tackle epistemic uncertainty affecting the model structure. We, therefore, suggest a paradigm shift in the current pollutant modelling approaches by adding a term explicitly accounting for epistemic uncertainties. In a proof-of-concept, we use this approach to investigate the impact of epistemic uncertainty in the fluctuation of pollutants during wet-weather discharge (input information) on the distribution of mass of pollutants (output distributions). We found that the range of variability negatively impacts the tail of output distributions. The fluctuation time, associated with high covariance between discharge and concentration, is a major driver for the output distributions. Adapting to different levels of epistemic uncertainty, our approach helps to identify critical unknown information in the fluctuation of pollutant concentration. Such information can be used in a risk management context and to design smart monitoring campaigns.

Marine plastics, circular economy, and artificial intelligence: A comprehensive review of challenges, solutions, and policies

Global plastic production is rapidly increasing, resulting in significant amounts of plastic entering the marine environment. This makes marine litter one of the most critical environmental concerns. Determining the effects of this waste on marine animals, particularly endangered organisms, and the health of the oceans is now one of the top environmental priorities. This article reviews the sources of plastic production, its entry into the oceans and the food chain, the potential threat to aquatic animals and humans, the challenges of plastic waste in the oceans, the existing laws and regulations in this field, and strategies. Using conceptual models, this study looks at a circular economy framework for energy recovery from ocean plastic wastes. It does this by drawing on debates about AI-based systems for smart management. In the last sections of the present research, a novel soft sensor is designed for the prediction of accumulated ocean plastic waste based on social development features and the application of machine learning computations. Plus, the best scenario of ocean plastic waste management with a concentration on both energy consumption and greenhouse gas emissions is discussed using USEPA-WARM modeling. Finally, a circular economy concept and ocean plastic waste management policies are modeled based on the strategies of different countries. We deal with green chemistry and the replacement of plastics derived from fossil sources.

Sources, Degradation, Ingestion and Effects of Microplastics on Humans: A Review

Celluloid, the predecessor to plastic, was synthesized in 1869, and due to technological advancements, plastic products appear to be ubiquitous in daily life. The massive production, rampant usage, and inadequate disposal of plastic products have led to severe environmental pollution. Consequently, reducing the employment of plastic has emerged as a pressing concern for governments globally. This review explores microplastics, including their origins, absorption, and harmful effects on the environment and humans. Several methods exist for breaking down plastics, including thermal, mechanical, light, catalytic, and biological processes. Despite these methods, microplastics (MPs, between 1 and 5 mm in size) continue to be produced during degradation. Acknowledging the significant threat that MPs pose to the environment and human health is imperative. This form of pollution is pervasive in the air and food and infiltrates our bodies through ingestion, inhalation, or skin contact. It is essential to assess the potential hazards that MPs can introduce. There is evidence suggesting that MPs may have negative impacts on different areas of human health. These include the respiratory, gastrointestinal, immune, nervous, and reproductive systems, the liver and organs, the skin, and even the placenta and placental barrier. It is encouraging to see that most of the countries have taken steps to regulate plastic particles. These measures aim to reduce plastic usage, which is essential today. At the same time, this review summarizes the degradation mechanism of plastics, their impact on human health, and plastic reduction policies worldwide. It provides valuable information for future research on MPs and regulatory development.

Bio-straw or not? Determinants of consumption intention under the plastic straw ban

A new plastic ban has banned the use of single-use non-degradable plastic drinking straws in China's food and beverage industry by the end of 2020. However, this has caused widespread discussion and complaints on social media. What are consumers' reactions and what factors influence consumers to choose bio-straws (substitutes for plastic straws) are unclear. Therefore, this research collected 4367 effective comments (177,832 words in total) on "bio-straws" from social media and extracted keywords based on grounded theory to generate questionnaires. Structural equation modeling was used to analyze the consumption intention and influencing factors of 348 consumers regarding the ban. The results indicate the following: (1) consumer opinion on straws can be summarized into five main categories, namely, consumers' user experience, consumer subjectivity, policy awareness, policy acceptance, and consumption intention; (2) consumer subjectivity, policy awareness, and policy acceptance directly affect consumption intention significantly, while user experience affects consumption intention indirectly; and (3) user experience and consumer subjectivity play significant roles in mediating these relationships. From the perspective of consumers, this study provides an important basis for policymakers to formulate single-use plastic alternative policies in the future.

Acceptability of a behaviour change intervention aimed at increasing the use of a reusable hot drink cup

Plastic pollution is an acute issue, with single-use plastic contributing to it significantly. It is beneficial for the planet if we engage in more sustainable behaviors, such as using reusable items instead of single-use ones, thus reducing plastic pollution. We implemented an intervention to increase the use of reusable coffee cups, by employing behavior change techniques that targeted values towards environment, intention to use a reusable cup, and habit. The intervention was successful in increasing the participants' use of reusable cups. The aim of the current study was to evaluate the acceptability of the intervention and research methods, as well as opinions of participants about the process and intervention effectiveness, using a mixed methods approach. Participants (N = 156) answered open and closed survey questions about the acceptability of the intervention, and 11 participated in interviews regarding their experience of intervention. The intervention was deemed acceptable and useful by all participants, regardless of which intervention condition they were allocated to, according to both survey and interview data. Men, however, evaluated the intervention as less personally relevant than women, with overall participation of men in the intervention being smaller than women. Recommendations for implementing similar interventions and future research are offered.

Marine litter and climate change: Inextricably connected threats to the world's oceans

The global issues of climate change and marine litter are interlinked and understanding these connections is key to managing their combined risks to marine biodiversity and ultimately society. For example, fossil fuel-based plastics cause direct emissions of greenhouse gases and therefore are an important contributing factor to climate change, while other impacts of plastics can manifest as alterations in key species and habitats in coastal and marine environments. Marine litter is acknowledged as a threat multiplier that acts with other stressors such as climate change to cause far greater damage than if they occurred in isolation. On the other hand, while climate change can lead to increased inputs of litter into the marine environment, the presence of marine litter can also undermine the climate resilience of marine ecosystems. There is increasing evidence that that climate change and marine litter are inextricably linked, although these interactions and the resulting effects vary widely across oceanic regions and depend on the particular characteristics of specific marine environments. Ecosystem resilience approaches, that integrate climate change with other local stressors, offer a suitable framework to incorporate the consideration of marine litter where that is deemed to be a risk, and to steer, coordinate and prioritise research and monitoring, as well as management, policy, planning and action to effectively tackle the combined risks and impacts from climate change and marine litter.

Is conscientious beachcombing the key to 'unlock' marine plastic pollution trends through citizen science? A case study from Cockburn Sound, Western Australia

Despite the global implementation of plastic waste reduction policies and bans on single use plastics (SuPs), their effectiveness for protecting marine ecosystems remains unclear. Frequent monitoring could confirm policy effectiveness, but this is difficult due to resourcing and logistic constraints. This study tested a 'beach litter' beachcombing citizen science approach that could overcome some constraints. Between November 2018 and January 2021, 168 beach visits led to the collection of 12,659 pieces of litter from a beach in Western Australia. Litter was predominantly plastic (87%) and mostly associated with fishing/boating (34%). Significant reductions in six types of litter, including fishing/boating items, balloons, and straws were detected and four coincided with local government waste mitigation measures. We show potential to harness conscientious beachcombers as citizen scientists to help evaluate plastic policy impact. Furthermore, we propose how to harness this effort and increase spatial and temporal coverage of marine plastic pollution monitoring.

The past, present, and future of plastic pollution

Plastic production is an essential part of the world economy that has mushroomed exponentially with c.9.2 billion tonnes estimated to have been made between 1950 and 2017. Now, each year c.8-11 million tonnes of plastic waste escapes into the oceans. Plastic usage is varied but the packaging industry accounts for 47%. Recycling and the circular economy are seen as keys to unlocking the plastic problem, for example, via the Extended Producer Responsibility scheme; a Deposit Return Scheme. The circular economy is a fine idea and has been around a long time, but has it made any real difference? The amount of plastic in circulation keeps getting bigger and bigger. More thought must be given to creating technologies and designs that can deal with waste management, integrate international collaboration and cut waste to a bare minimum at its source point upstream. No single solution exists, but there is a need for a legally binding global governance arrangement that would effectively and measurably limit and control plastic pollution. Many governments are in favour of this.