Miriam L. Diamond

The use of chemical fingerprinting of microplastics (MPs) was evaluated to support source identification by (1) identifying treatment-driven changes in MP chemical fingerprints caused by artificial weathering and sample processing, and (2) testing the identification of MPs within MP mixtures to mimic environmental samples. A nontarget chemical fingerprint library was constructed from 15 pristine MPs using High-Performance Liquid Chromatography coupled with Quantitative Time-of-Flight Mass Spectrometry, and a Random Forest classifier was trained to classify treated MP counterparts. Results indicated that chemical fingerprints comprised both polymerization-based and functional additive-derived chemicals. The classifier correctly assigned all pristine MPs and retained 90% accuracy after artificial weathering and sample processing, despite treatment-driven changes in features that shifted fingerprint composition. Suspect screening analysis and Random Forest classifications showed that oxidative digestion had the greatest impact on MP fingerprints and identification, decreasing prediction probabilities by an average of 30% and altering MP fingerprint composition. In mixed-MP tests, MPs with unique fingerprints remained detectable, such as tire rubber, supporting targeted applications of the method. Overall, this work serves as a proof-of-concept of a novel fingerprinting method based on MP identification using plastic additive fingerprints, which could be further developed to identify MP sources, such as local polluters.

Knowledge on chemicals, waste, and pollution is shaped by geographical, financial, and disciplinary biases, which can cause blind spots for key emerging issues, including those relevant to low income countries and vulnerable communities. Scientists, practitioners, affected communities, and policy makers working in the areas of the newly established Intergovernmental Science-Policy Panel on Chemicals, Waste, and Pollution (ISP-CWP) have interest in identifying issues of potential and emerging relevance that currently escape their attention. Horizon scanning offers a critical tool to identify such issues. Here, we provide guidance on aligning horizon scanning approaches with differing objectives, audiences, and thematic scopes. We structure this guidance around three core dimensions: the topics addressed (“what”), the actors involved (“who”), and the methods applied (“how”). Drawing on existing horizon scanning efforts and foresight practices, we outline inclusive and transparent approaches suitable for prospective assessments across diverse contexts. Emphasis is placed on correcting epistemic asymmetries, integrating local and indigenous knowledge, and ensuring legitimacy for global governance processes. Strategically designed horizon scanning can support anticipatory policy, promote equity, and help steer collective action toward a livable planet for all.

Novel entities are diverse and complex; hence, defining their Planetary Boundary through control variables, indicators, and acceptable limits is challenging. Here, we highlight shortcomings of the current quantitative boundary, which applies a purely precautionary interpretation of safety that defines the safe operating space as zero novel entities that are not fully characterized. In practice, the zero limit is unattainable and undesirable for human societies that rely on services provided by novel entities. Furthermore, it is not operational within the framework of other boundaries, which have risk-based thresholds. We therefore propose a reboot of the Planetary Boundary for Novel Entities and recommend governance and monitoring strategies based on: (a) clarification of the "safe operating space" for novel entities, distinguishing pure precaution ("safe from the unknown") from operational precaution that tolerates a workable, non-zero level of uncertainty; (b) complementary, multilayer control variables spanning pressures, states, and impacts; (c) extensions to existing monitoring systems to provide quantitative indicators of distribution, accumulation, exposure, and impacts for subsets of novel entities to communicate the status and trends of stress from novel entities on the Earth system; and (d) recognition of regulatory and policy-related success stories that illustrate comprehensive, protective, and operational governance of novel entities.

Chemical pollution is a global threat to human health, yet the toxicity mechanisms of most contaminants remains unknown. Here, we applied an ultrahigh-throughput affinity selection–mass spectrometry (AS–MS) platform to systematically identify protein targets of prioritized chemical contaminants. After benchmarking the platform, we screened 50 human proteins against 481 prioritized chemicals, including 446 ToxCast chemicals and 35 per- and polyfluoroalkyl substances (PFAS). Among 24,050 interactions assessed, we discovered 35 interactions involving 13 proteins, with fatty acid–binding proteins (FABPs) emerging as the most ligandable protein family. Given this, we selected FABPs for further validation, which revealed a distinct PFAS binding pattern: legacy PFAS selectively bound to FABP1, whereas replacement compounds, perfluoroether carboxylic acids, unexpectedly interacted with all FABPs. X-ray crystallography further revealed that the ether group enhances the molecular flexibility of alternative PFAS to accommodate the binding pockets of FABPs. Our findings demonstrate that AS–MS is a robust platform for the discovery of protein targets beyond the scope of ToxCast and highlight the broader protein-binding spectrum of alternative PFAS as potential regrettable substitutes.

Per- and polyfluoroalkyl substances (PFAS) have been used in many applications, including electronic products, but little is known about the presence of PFAS in e-waste facilities, especially in North America. In this study, we investigated 87 legacy and novel PFAS in indoor dust samples (n = 19) from two Canadian e-waste dismantling facilities. PFAS were detected in all samples in the range of 364–6090 ng g⁻¹ for Σ₆₄PFAS with a median of 1150 ng g⁻¹. Polyfluoroalkyl phosphate esters (PAPs) were generally the most abundant group of compounds detected and ultrashort PFAS were detected in dust for the first time. After hydrolysis, the concentrations of 3 fluorotelomer alcohols (6 : 2 FTOH, 8 : 2 FTOH and 10 : 2 FTOH) increased ∼100 times, and those of 3 perfluorooctane sulfonamido ethanol (FASEs; MEFBSE, MeFOSE and EtFOSE) by 20, 20 and 5 times, respectively. After the direct total oxidizable precursor (dTOP) assay, used here in dust for the first time, the levels of perfluoroalkyl carboxylic acids (PFCAs) increased by up to 290 times. These results suggest that there are significant amounts of perfluoroalkyl acid (PFAA) precursors in the e-waste dust samples. Estimated worker exposure via dust ingestion exceeded the US EPA chronic reference dosage for perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in the intermediate and high-risk scenarios. The presence of PFAS in dust from e-waste electrical and electronic dismantling facilities is a serious concern in terms of both occupational exposure and the risks associated with environmental release from recycling facilities.

Environmentally hazardous pharmaceuticals continue to be produced, used, and released to the environment, despite growing recognition of the need for greener drug design. This study applies a "lock-in" analytical framework to examine how various interacting social, economic, political, and technological factors prevent the effective implementation of concepts such as "benign by design" in drug development. Using a combination of qualitative and quantitative methods, including analysis of US and European clinical trial records, we identify two critical lock-ins: (1) misaligned timing of resources and expertise among key actors that prevents early integration of environmental safety and sustainability considerations in drug design, and (2) incentive structures that promote new drug development over the redesign of existing pharmaceuticals. Notably, this analysis identifies barriers to greening both future and existing drugs on the market. Building on Meadows' framework for effective interventions in complex systems, we propose a strategic approach for breaking lock-ins and present specific recommendations for key stakeholder groups including policymakers, academia, small biotech, big pharma, and financial institutions. Addressing these lock-ins is essential to unlocking the full potential of green innovation in pharmaceutical development, while providing for patient access to essential medicines.