Planetary Sustainability

SILENT ACCUMULATION OF MICROPLASTIC POLLUTION IN TERRESTRIAL ECOSYSTEMS

2026-06-10T20:09:43+08:00

Microplastic (MP) pollution is widely recognised as a global environmental challenge, yet scientific and policy attention has focused predominantly on aquatic ecosystems despite growing evidence that terrestrial environments are major and increasingly recognised, sinks of plastic contamination. Global plastic production has already exceeded 400 Mt annually and is projected to surpass 1,100 Mt by 2060 under business-as-usual scenarios. While an estimated 19 to 23 Mt of plastic waste enters aquatic ecosystems each year, terrestrial inputs are believed to be substantially higher under many current estimates, due to agricultural plastics, sewage sludge application, atmospheric deposition, urban runoff, and landfill leakage. Consequently, soils are becoming long-term reservoirs of plastic pollution through the process we define here as “silent accumulation”, the progressive, often unnoticed build-up, persistence, fragmentation, and continuous generation of secondary micro- and nanoplastics within terrestrial ecosystems. Although existing studies have documented sources, pathways, occurrence, and ecological effects of MPs in soils, this perspective moves beyond a descriptive synthesis by introducing the concept of silent accumulation as a conceptual framework and integrating current evidence with published future scenarios to examine how terrestrial microplastic contamination may evolve under business-as-usual conditions. Current evidence demonstrates that MPs can alter soil structure, microbial communities, soil fauna, nutrient cycling, and plant performance, whereas published OECD and UNEP projections suggest that continued increases in plastic production, waste generation, environmental leakage, and secondary microplastic formation could intensify terrestrial MP accumulation throughout the coming decades. Major uncertainties remain regarding long-term accumulation rates, ecological thresholds, legacy plastic fragmentation, climate-change interactions, and future contamination burdens. We therefore highlight the need for coordinated global monitoring networks, long-term datasets, and predictive models capable of forecasting terrestrial MP trajectories and identifying critical stress thresholds. Advancing terrestrial microplastic research from a largely descriptive field toward a predictive science is essential for informing preventive policies, protecting soil health, and safeguarding the long-term sustainability of terrestrial ecosystems through standardised monitoring, long-term field studies, predictive modelling, source prevention, and rigorous evaluation of sustainable alternative materials.

PRODUCTION OF POLYMER-PRECURSOR CARBOXYLIC ACIDS FROM MUNICIPAL SOLID WASTE: FERMENTATION, CHAIN ELONGATION, AND DOWNSTREAM PROCESSING

2026-06-16T16:13:02+08:00

Municipal solid waste (MSW) represents an underutilised feedstock for the production of polymer-precursor carboxylic acids via the carboxylate platform and chain elongation. This preliminary review examines the production of four key building blocks from the organic fraction of MSW: Butyric acid (C4, precursor to polyhydroxybutyrate), caproic acid (C6, precursor to polyhydroxycaproate), lactic acid (C3, precursor to polylactic acid), and succinic acid (C4, precursor to polybutylene succinate). For each chemical, fermentation strategies, key microorganisms, and separation technologies are reviewed. Lactic acid achieves the highest yields and titres but suffers from optical purity issues from mixed MSW cultures. Butyric acid offers the best overall balance of yield, productivity, and separation feasibility. Caproic acid requires chain elongation with external electron donors, resulting in lower yields and titres, and limiting its economic viability. Succinic acid is the least mature, with low yields and high separation costs. Key knowledge gaps include contaminant impacts on chain-elongating consortia, process integration at pilot scale, and low-cost separation technologies compatible with MSW solids.

WAR AND SUSTAINABILITY: THE TWO-WAY RELATIONSHIP BETWEEN CONFLICT AND UNSUSTAINABLE DEVELOPMENT

2026-05-27T14:44:50+08:00

Wars and armed conflicts are inherently destructive, and their impacts extend far beyond military resources and intended targets. Generally speaking, the damage caused by wars and conflict extend even beyond civilian populations and facilities, this spillover often referred to as collateral damage, there are numerous additional victims of wars and conflicts, which includes animals, plants, natural resources, biodiversity, and climate systems and ecosystems. Wars and conflicts, which may represent both drivers and consequences of shortcomings in Sustainable development goals (SDG), specifically SDG16, which has to do with (Peace, Justice and Strong Institutions Wars and other conflicts also negatively affect the progress across of almost all other Sustainable Development Goals (SDGs), including poverty reduction, health and well-being, food security, economic development, education, equity as well as goals related to natural resources and the environment. Consequently, wars and other conflicts constitute major barriers to achieving sustainable development. The consequences of wars and armed conflicts on global sustainability, natural resources, biodiversity, and climate systems are widespread, long-lasting, and potentially intergenerational. Although these impacts have received increasing attention in international documents and protocols, they continue to be inadequately addressed by military powers that often fail to safeguard even civilian populations. The most effective mitigation strategy for the sustainability impacts of wars and armed conflicts is prevention; however, such efforts frequently fail. Regarding the environmental consequences of wars and armed conflicts, we argue that the current limited initiatives for documenting these impacts should be expanded into an independent global surveillance system to systematically identify, monitor, analyse, and inform policies and interventions. We also call for sustainability-related taxation of military industries to partially and pre-emptively compensate for their destructive contributions to planetary sustainability.

LIGNIN-BASED ACTIVE FOOD PACKAGING: FROM FUNCTIONAL PROMISE TO FOOD-USE READINESS AND PRACTICAL CHALLENGES

2026-05-27T15:00:53+08:00

Lignin-based active food packaging has emerged as a promising route for linking food preservation, renewable material use, and valorisation of lignocellulosic side streams. The aromatic and phenolic structure of lignin enables ultraviolet shielding, radical scavenging, interfacial reinforcement, and barrier improvement in biodegradable films and coatings. Nevertheless, these material functions do not automatically establish practical readiness for food packaging. This critical review evaluates the progress of lignin-based active packaging from laboratory film development toward food-use application by connecting structure–function relationships with real food preservation, food-contact safety, migration, sensory quality, processing scalability, environmental performance, economic feasibility, and regulatory credibility. Current evidence supports lignin most strongly as a UV-protective and antioxidant additive, whereas antimicrobial performance remains less predictable and depends on lignin source, extraction route, molecular structure, particle form, polymer matrix, formulation design, and target food system. Recent studies on bread, mango, fish, banana, strawberry, apple, tomato, ketchup, and other perishable foods demonstrate encouraging preservation effects, particularly when lignin is used within designed active systems rather than as a standalone preservative. However, the field remains dominated by material-level characterisation, with limited standardised lignin reporting, real-food validation, migration and toxicity assessment, sensory analysis, regulatory evaluation, and integrated techno-economic and life cycle assessment. The most defensible pathway forward is application-specific validation, where lignin functions are matched to defined deterioration mechanisms such as photooxidation, lipid oxidation, fungal spoilage, moisture loss, browning, or barrier failure. This shift is necessary for advancing lignin-based active food packaging from a promising material concept toward an evidence-based food-packaging technology.

OPTIMISING THE POST-CONSUMER PLASTIC CLOSED-LOOP ECONOMY APPROACH FOR EMERGING NATIONS: A SYSTEMATIC LITERATURE REVIEW

2026-06-20T22:04:20+08:00

A systematic review of the literature on the application of circular economy approaches for plastic waste management in developing nations was conducted. Based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) methodological guidelines and Scopus, articles between 2006 and 2025 have been screened, appraised using the Mixed Methods Appraisal Tool, and thematically analysed. Out of 10,792 articles, 13 articles of high quality passed the inclusion criteria set by the researchers. This study found four major themes, which are: closed loop economy practices, regulation and policy intervention, public involvement and awareness, and technological innovations. This paper finds that mechanical recycling, source separation, reuse, upcycling, and informal sector collections of plastics are the most used circular economy approaches. The review further highlights that community education, behaviour modification, and stakeholder collaboration are necessary in improving waste segregation and involvement in the recycling process. Nevertheless, implementation is hampered by factors including weak institutional setup, lack of adequate infrastructure, insufficient funding, market exclusion, and low level of awareness among the people. Waste-to-energy approach, plastic waste to construction material, and digital waste management are some of the new emerging practices highlighted in the review as possible alternatives but yet limited in scope. All in all, the findings of this review indicate that the move towards circular plastic waste management in developing nations will have to involve an integrated system which incorporates governance, policies, technology and people.