Cross-resistance of UV- or chlorine dioxide-resistant echovirus 11 to other disinfectants

The emergence of waterborne viruses with resistance to disinfection has been demonstrated in the laboratory and in the environment. Yet, the implications of such resistance for virus control remain obscure. In this study we investigate if viruses with resistance to a given disinfection method exhibit cross-resistance to other disinfectants. Chlorine dioxide (ClO2)- or UV-resistant populations of echovirus 11 were exposed to five inactivating treatments (free chlorine, ClO2, UV radiation, sunlight and heat), and the extent of cross-resistance was determined. The ClO2-resistant population exhibited cross-resistance to free chlorine, but to none of the other inactivating treatments tested. We furthermore demonstrated that ClO2 and free chlorine act by a similar mechanism, in that they mainly inhibit the binding of echovirus 11 to its host cell. As such, viruses with host binding mechanisms that can withstand ClO2 treatment were also better able to withstand oxidation by free chlorine. Conversely, the UV-resistant population was not significantly cross-resistant to any other disinfection treatment. Overall, our results indicate that viruses with resistance to multiple disinfectants exist, but that they can be controlled by inactivating methods that operate by a distinctly different mechanism. We therefore suggest to utilize two disinfection barriers that act by different mechanisms in order to control disinfection-resistant viruses

United Nations Environment Programme (UNEP), Questions and Answers about the Effects of Ozone Depletion, UV Radiation, and Climate on Humans and the Environment. Supplement of the 2022 Assessment Report of the UNEP Environmental Effects Assessment Panel

This collection of Questions & Answers (Q&As) was prepared by the Environmental Effects Assessment Panel (EEAP) of the Montreal Protocol under the umbrella of the United Nations Environment Programme (UNEP). The document complements EEAP’s Quadrennial Assessment 2022 (https://ozone. unep.org/science/assessment/eeap) and provides interesting and useful information for policymakers, the general public, teachers, and scientists, written in an easy-to-understand language

Plastics in the environment in the context of UV radiation, climate change and the Montreal Protocol: UNEP Environmental Effects Assessment Panel, Update 2023

This Assessment Update by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) considers the interactive effects of solar UV radiation, global warming, and other weathering factors on plastics. The Assessment illustrates the significance of solar UV radiation in decreasing the durability of plastic materials, degradation of plastic debris, formation of micro- and nanoplastic particles and accompanying leaching of potential toxic compounds. Micro- and nanoplastics have been found in all ecosystems, the atmosphere, and in humans. While the potential biological risks are not yet well-established, the widespread and increasing occurrence of plastic pollution is reason for continuing research and monitoring. Plastic debris persists after its intended life in soils, water bodies and the atmosphere as well as in living organisms. To counteract accumulation of plastics in the environment, the lifetime of novel plastics or plastic alternatives should better match the functional life of products, with eventual breakdown releasing harmless substances to the environment

United Nations Environment Programme (UNEP), Plastics in the environment in the context of UV radiation, climate change and the Montreal Protocol. 2023 Assessment Update of the UNEP Environmental Effects Assessment Panel

Solar ultraviolet radiation is a contributing factor in the environmental fate of toxic chemicals and other contaminants, with consequences that may be either beneficial or detrimental for the health of humans and the environment. This Assessment Update (2023) by the Environmental Effects Assessment Panel (EEAP) focusses on the role and significance of UV radiation and associated drivers on the breakdown of plastic waste in the environment. Plastic is a ubiquitous pollutant. UV radiation and mechanical stress drive the degradation and fragmentation of larger plastic waste into smaller micro- and nanoplastics. The Assessment Update considers the interactive effects of UV radiation and climate change on plastic durability, weathering, longevity, and ultimately the fate of plastic debris

Environmental plastics in the context of UV radiation, climate change, and the Montreal Protocol

There are close links between solar UV radiation, climate change, and plastic pollution. UV-driven weathering is a key process leading to the degradation of plastics in the environment but also the formation of potentially harmful plastic fragments such as micro- and nanoplastic particles. Estimates of the environmental persistence of plastic pollution, and the formation of fragments, will need to take in account plastic dispersal around the globe, as well as projected UV radiation levels and climate change factors. UV radiation, climate change, and plastic pollution are closely interlinked. Existing studies on the persistence of plastics do not fully consider these linkages, challenging global assessments of plastic dispersal, persistence, and weathering. Recently, an Intergovernmental Negotiating Committee was tasked with developing an international binding agreement to end plastic pollution. In response, the UNEP Environmental Effects Assessment Panel assessed effects of UV radiation and interacting climate change factors on plastics, focusing on the durability of products as well as the production and dispersal of micro- and nano-plastic pollutants in the environment

The chemical landscape of leaf surfaces and its interaction with the atmosphere

Atmospheric chemists have historically treated plant leaves as inert surfaces that merely emit volatile hydrocarbons through their stomata. However, a growing body of evidence suggests that leaves are ubiquitous substrates for multiphase reactions of atmospheric relevance – implying the presence of chemicals on their surfaces. This Review provides an evidence-based overview of the chemistry and reactivity of the leaf surface’s “chemical landscape”, the dynamic ensemble of molecules and particles that cover plant leaves. We classified chemicals as endogenous (originating from the leaf and its biome) or exogenous (delivered from the environment), highlighting the biological, geographical, and meteorological factors driving their relative contributions. Based on available data, we predicted ≫ 2 µg cm-2 of organics on a typical leaf, leading to a global estimate of ≫ 3 Tg available for multiphase reactions. Our work also highlighted three major knowledge gaps: (i) the key (but still overlooked) role of ambient water in enabling the leaching of endogenous substances and mediating aqueous chemistry; (ii) the role of phyllosphere biofilms in shaping leaf surface chemistry and reactivity; (iii) the paucity of studies on the multiphase reactivity of main atmospheric oxidants with leaf-adsorbed chemicals. Although biased towards available data, we hope this Review will spark a renewed interest on the leaf surface’s chemical landscape and motivate the establishment of multidisciplinary collaborations to move the field forward

Mechanistic Insights into Dissolved Organic Sulfur Photomineralization through the Study of Cysteine Sulfinic Acid

Photochemical reactions convert dissolved organic matter (DOM) into inorganic and low-molecular-weight organic products, contributing to its cycling across environmental compartments. However, knowledge on the formation mechanisms of these products is still scarce. In this work, we investigate the triplet-sensitized photodegradation of cysteine sulfinic acid, a (photo)degradation product of cysteine, to sulfate (SO42–). We use kinetic analysis, targeted experiments, and previous literature from several fields of chemistry to explain the elementary steps that lead to the release of sulfate. Our analysis indicates that triplet sensitizers act as one-electron oxidants on the sulfinate S lone pair. The resulting radical undergoes C–S fragmentation to form SO2, which becomes hydrated to sulfite/bisulfite (S(IV)). S(IV) is further oxidized to SO42– in the presence of triplet sensitizers and oxygen. We point out that the reaction sequence SO2 ⇌ S(IV) → SO42– is valid independently of the chemical structure of the model compound and might represent a sulfate photoproduction mechanism with general validity for DOS. Our mechanistic investigation revealed that amino acids in general might also be photochemical precursors of CO2, ammonia, acetaldehyde, and H2O2 and that reaction byproducts can influence the rate and mechanism of S(IV) (photo)oxidation.ISSN:0013-936XISSN:1520-585

Singlet Oxygen Quantum Yields in Environmental Waters

Singlet oxygen (1O2) is a reactive oxygen species produced in sunlit waters via energy transfer from the triplet states of natural sensitizers. There has been an increasing interest in measuring apparent 1O2 quantum yields (ΦΔ) of aquatic and atmospheric organic matter samples, driven in part by the fact that this parameter can be used for environmental fate modeling of organic contaminants and to advance our understanding of dissolved organic matter photophysics. However, the lack of reproducibility across research groups and publications remains a challenge that significantly limits the usability of literature data. In the first part of this review, we critically evaluate the experimental techniques that have been used to determine ΦΔ values of natural organic matter, we identify and quantify sources of errors that potentially explain the large variability in the literature, and we provide general experimental recommendations for future studies. In the second part, we provide a qualitative overview of known ΦΔ trends as a function of organic matter type, isolation and extraction procedures, bulk water chemistry parameters, molecular and spectroscopic organic matter features, chemical treatments, wavelength, season, and location. This review is supplemented with a comprehensive database of ΦΔ values of environmental samples.ISSN:0009-2665ISSN:1520-689