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.

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.

Health Problems of Increasing Man-Made and Climate-Related Disasters on Forcibly Displaced populations: A Scoping Review on Global Evidence.

Forcibly displaced populations are among the most vulnerable groups in disasters. They experience poorer health conditions compared with nondisplaced individuals. However, a clear picture is lacking regarding the overall health problems encountered by disaster-induced mid- to long-term displaced people. This study investigated these disorders prevalence and identified their correlates among long-settled displaced populations worldwide. The current scoping review follows the PRISMA-ScR guidelines; a systematic search was conducted on PubMed, Web of Science, and CINAHL and included original peer-reviewed studies, commentary, reviews, and grey literature published in English between January 1990 to June 2022. In the thematic and content analysis, the authors applied the narrative review approach to identify themes and sub-themes. Forty-eight documents were identified as fully relevant to this study. The largest number of published papers were from Asia, followed by the Middle East, the United States, and Europe. IDPs in developed countries were the most researched populations. Human-made disasters were addressed by 89% of the included studies. The four main thematic categories included were "physical health," "mental health," "inadequate facilities," and "lack of healthy behaviour." The worsening of noncommunicable diseases had the highest prevalence, followed by communicable diseases. Due to their condition, forcibly displaced migrants face a triple burden of communicable diseases and noncommunicable diseases such as mental health issues. Health-related research and policy need to consider the links among disasters, health problems, and forced migration as a determinant of health in the new era of climate change-driven displacements.

Rethinking entrenched narratives about protected areas and human wellbeing in the Global South.

Attempts to link human development and biodiversity conservation goals remain a constant feature of policy and practice related to protected areas (PAs). Underlying these approaches are narratives that simplify assumptions, shaping how interventions are designed and implemented. We examine evidence for five key narratives: 1) conservation is pro-poor; 2) poverty reduction benefits conservation; 3) compensation neutralises costs of conservation; 4) local participation is good for conservation; 5) secure tenure rights for local communities support effective conservation. Through a mixed-method synthesis combining a review of 100 peer-reviewed papers and 25 expert interviews, we examined if and how each narrative is supported or countered by the evidence. The first three narratives are particularly problematic. PAs can reduce material poverty, but exclusion brings substantial local costs to wellbeing, often felt by the poorest. Poverty reduction will not inevitably deliver on conservation goals and trade-offs are common. Compensation (for damage due to human wildlife conflict, or for opportunity costs), is rarely sufficient or commensurate with costs to wellbeing and experienced injustices. There is more support for narratives 4 and 5 on participation and secure tenure rights, highlighting the importance of redistributing power towards Indigenous Peoples and Local Communities in successful conservation. In light of the proposed expansion of PAs under the post-2020 Global Biodiversity Framework, we outline implications of our review for the enhancement and implementation of global targets in order to proactively integrate social equity into conservation and the accountability of conservation actors.

The Function of Flavonoids in the Diurnal Rhythm under Rapidly Changing UV Conditions-A Model Study on Okra.

Flavonoids are favored compounds in plant responses to UV exposure and act in UV absorption and antioxidant activity. Here, it was investigated, with okra as a model species, how fast plants can react to changing UV conditions and to what extent these reactions take place. Okra (Abelmoschus esculentus) plants were exposed to either full or nearly no UV radiation. The diurnal rhythm of the plants was driven by the UV radiation and showed up to a 50% increase of the flavonoid content (measured optically in the +UV plants). This was reflected only in the trends in UV-absorption and antioxidant activity of the extracts but not in the soluble flavonoid glycosides and hydroxycinnamic acid derivatives. In a second experiment, a transfer from a -UV to a +UV condition at 9:00 CDT showed the immediate start of the diurnal rhythm, while this did not occur if the transfer occurred later in the day; these plants only started a diurnal rhythm the following day. After an adaptation period of seven days, clear differences between the +UV and -UV plants could be found in all parameters, whereas plants transferred to the opposite UV condition settle between the +UV and -UV plants in all parameters. Broadly, it can be seen that the flavonoid contents and associated functions in the plant are subject to considerable changes within one day and within several days due to the UV conditions and that this can have a considerable impact on the quality of plant foods.

Rapid adjustment in epidermal UV sunscreen: Comparison of optical measurement techniques and response to changing solar UV radiation conditions.

The accumulation of soluble and cell-wall bound UV-absorbing compounds (i.e., flavonoids) in the epidermis and the mesophyll of leaves is a response of plants to UV exposure. These compounds are known to function in UV screening, but they are also of potential value for food quality. One way to non-destructively monitor UV screening in leaves is by optical methods, from which UVA-PAM and Dualex instruments stand out. The degree and rapidity to which plants can modulate UV screening in response to fluctuating solar UV conditions is poorly understood. In this study, okra plants were exposed to two solar radiation treatments (near-ambient UV [+UV] and attenuated UV [-UV]) and the epidermal UV transmittance (TUV ; UVA-PAM) and flavonoid index (Dualex) were measured in the youngest and second youngest mature leaves over three consecutive days and within an individual day. The day-to-day (measured near solar noon) and diurnal (over the course of a day) measurements of leaf optical properties indicated that TUV decreased and flavonoid index increased in the adaxial epidermis ~50% until 15:00 CDT then returned close to morning values later in the day. Correlations between UV-B radiation and TUV and flavonoid index revealed highest values 30 min to 1 h prior to the measurements. These findings indicate that plants can respond quickly to fluctuating solar UV conditions and underlines the importance of the harvest-time point for health-promoting compounds in fruit and vegetables. Our findings also indicate that the UVA-PAM and the Dualex instruments are both suitable instruments to monitor rapid changes in UV screening in plants.

The success of the Montreal Protocol in mitigating interactive effects of stratospheric ozone depletion and climate change on the environment.

The Montreal Protocol and its Amendments have been highly effective in protecting the stratospheric ozone layer, preventing global increases in solar ultraviolet-B radiation (UV-B; 280-315 nm) at Earth's surface, and reducing global warming. While ongoing and projected changes in UV-B radiation and climate still pose a threat to human health, food security, air and water quality, terrestrial and aquatic ecosystems, and construction materials and fabrics, the Montreal Protocol continues to play a critical role in protecting Earth's inhabitants and ecosystems by addressing many of the United Nations Sustainable Development Goals.

Floral bullseyes and stratospheric ozone.

As well as guiding pollinators to the centre of flowers, areas of the corolla that absorb UV radiation may help to protect floral reproductive parts from solar UV radiation that would otherwise be reflected onto them. In their recent article, 'Floral pigmentation has responded rapidly to global change in ozone and temperature', Koski et al.1 compared herbarium specimens collected between 1941 and 2017 to investigate whether the size of the UV-absorbing area in the centre of flowers (called 'bullseyes', UV proportion, or UVP) has changed relative to the size of the flower over this period. The article, and a subsequent feature2, describe an increase in UVP of ∼2% per year across all taxa examined. However, the study's main conclusion that this trend can be partially related to changes in ozone and temperature does not withstand close examination.

Cyclic imine toxins survey in coastal european shellfish samples: Bioaccumulation and mode of action of 28-O-palmitoyl ester of pinnatoxin-G. first report of portimine-A bioaccumulation.

Cyclic imine toxins exhibit fast acting neurotoxicity and lethality by respiratory arrest in mice explained by their potent antagonistic activity against muscular nicotinic acetylcholine receptors. We performed a survey of gymnodimine-A, 13-desmethyl spirolide-C, 13,19-didesmethyl spirolide-C, 20-methyl spirolide-G, pinnatoxin-A, pinnatoxin-G, portimine-A and 28-O-palmitoyl ester of pinnatoxin-G in 36 shellfish samples collected in coastal areas of 8 European countries using a microplate receptor binding assay and UPLC-MS/MS for toxin identification and quantification. The major toxins found in these samples were pinnatoxin-G, 20-methyl spirolide-G, 13-desmethyl spirolide-C, gymnodimine-A and portimine-A. Traces of 13,19-didesmethyl spirolide-C, pinnatoxin-A and 28-O-palmitoyl ester of pinnatoxin-G were also detected. The rapid death of mice was correlated with higher pinnatoxin-G concentrations in mussel digestive gland extracts injected intraperitoneally. Our survey included nontoxic control samples that were found to contain moderate to trace amounts of several cyclic imine toxins. Shellfish may bioaccumulate not only cyclic imine toxins but also a large number of acyl derivatives as a product of metabolic transformation of these neurotoxins. This is the first report in which portimine-A and 28-O-palmitoyl ester of pinnatoxin-G were detected in shellfish extracts from digestive glands of mussels collected in Ingril lagoon. The bioaccumulation of portimine-A is particularly of concern because it is cytotoxic and is able to induce apotosis. The mode of action of 28-O-palmitoyl ester of pinnatoxin-G was studied by receptor binding-assay and by two-electrode voltage clamp electrophysiology. The antagonistic behavior of the acylated pinnatoxin-G towards nicotinic acetylcholine receptor of muscle type is shown here for the first time. Since cyclic imine toxins are not regulated further monitoring of these emerging toxins is needed to improve evidence gathering of their occurrence in shellfish commercialized for human consumption in Europe given their potent antagonism against muscle and neuronal nicotinic acetylcholine receptors.

Different irradiances of UV and PAR in the same ratios alter the flavonoid profiles of Arabidopsis thaliana wild types and UV-signalling pathway mutants.

The UVR8 photoreceptor in Arabidopsis thaliana is specific for ultraviolet-B (UV-B; 280-315 nm) radiation and its activation leads to a number of UV-B acclimation responses, including the accumulation of flavonoids. UVR8 participates in a signaling cascade involving COP1 and HY5 so that the absence of any of these components results in a reduction in the ability of a plant to accumulate flavonoids in response to UV; Cop1 mutants show high dropouts and hy5-ks50 hyh double mutants show very low levels of flavonoids. The predominant phenolics in Arabidopsis thaliana are sinapic acid derivatives as well as non-aclyated quercetin and kaempferol di- and triglycosides containing glucose and rhamnose as glycosylated sugar moieties. How this flavonoid profile in Arabidopsis thaliana is affected by UV radiation, how rapidly these changes occur in changing UV conditions, and which components of the UV-B signalling pathway are involved in rapid UV acclimatization reactions is poorly understood. In the present study, we examined these questions by characterizing the flavonoid profiles of Arabidopsis thaliana signalling mutants and wild types grown under different UV levels of constant UV-B+PAR ratios and then transferring a subset of plants to alternate UV conditions. Results indicate that flavonoid accumulation in Arabidopsis thaliana is triggered by UV and this response is amplified by higher levels of UV but not by all compounds to the same extent. The catechol structure in quercetin seems to be less important than the glycosylation pattern, e.g. having 2 rhamnose moieties in determining responsivity. At low UV+PAR intensities the introduction of UV leads to an initial tendency of increase of flavonoids in the wild types that was detected after 3 days. It took 7 days for these changes to be detected in plants grown under high UV+PAR intensities suggesting a priming of PAR. Thus, the flavonoid profile in Arabidopsis thaliana is altered over time following exposure to UV and PAR, but the functional significance of these changes is currently unclear.

Comparing the impacts of climate change on the responses and linkages between terrestrial and aquatic ecosystems.

Aquatic and terrestrial organisms are being exposed to a number of anthropogenically-induced environmental stresses as a consequence of climate change. In addition, climate change is altering various linkages that exist between ecosystems on land and in water. Here we compare and contrast how climate change is altering aquatic and terrestrial environments and address some of the ways that the organisms in these ecosystems, especially the primary producers, are being affected by climate change factors, including changes in temperature, moisture, atmospheric carbon dioxide and solar UV radiation. Whereas there are some responses to climate change in common between terrestrial and aquatic ecosystems (e.g., changes in species composition and shifting geographic ranges and distributions), there are also responses that fundamentally differ between these two (e.g., responses to UV radiation). Climate change is also disrupting land-water connections in ways that influence biogeochemical and hydrologic cycles, and biosphere-atmosphere interactions in ways that can modify how aquatic and terrestrial ecosystems are affected by climate change and can influence climate change. The effects of climate change on these ecosystems are having wide-ranging effects on ecosystem biodiversity, structure and function and the abilities of these systems to provide essential services.

Early exposure to UV radiation overshadowed by precipitation and litter quality as drivers of decomposition in the northern Chihuahuan Desert.

Dryland ecosystems cover nearly 45% of the Earth's land area and account for large proportions of terrestrial net primary production and carbon pools. However, predicting rates of plant litter decomposition in these vast ecosystems has proven challenging due to their distinctly dry and often hot climate regimes, and potentially unique physical drivers of decomposition. In this study, we elucidated the role of photopriming, i.e. exposure of standing dead leaf litter to solar radiation prior to litter drop that would chemically change litter and enhance biotic decay of fallen litter. We exposed litter substrates to three different UV radiation treatments simulating three-months of UV radiation exposure in southern New Mexico: no light, UVA+UVB+Visible, and UVA+Visible. There were three litter types: mesquite leaflets (Prosopis glandulosa, litter with high nitrogen (N) concentration), filter paper (pure cellulose), and basswood (Tilia spp, high lignin concentration). We deployed the photoprimed litter in the field within a large scale precipitation manipulation experiment: ∼50% precipitation reduction, ∼150% precipitation addition, and ambient control. Our results revealed the importance of litter substrate, particularly N content, for overall decomposition in drylands, as neither filter paper nor basswood exhibited measurable mass loss over the course of the year-long study, while high N-containing mesquite litter exhibited potential mass loss. We saw no effect of photopriming on subsequent microbial decay. We did observe a precipitation effect on mesquite where the rate of decay was more rapid in ambient and precipitation addition treatments than in the drought treatment. Overall, we found that precipitation and N played a critical role in litter mass loss. In contrast, photopriming had no detected effects on mass loss over the course of our year-long study. These results underpin the importance of biotic-driven decomposition, even in the presence of photopriming, for understanding litter decomposition and biogeochemical cycles in drylands.

A perspective on ecologically relevant plant-UV research and its practical application.

Plants perceive ultraviolet-B (UV-B) radiation through the UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8), and initiate regulatory responses via associated signalling networks, gene expression and metabolic pathways. Various regulatory adaptations to UV-B radiation enable plants to harvest information about fluctuations in UV-B irradiance and spectral composition in natural environments, and to defend themselves against UV-B exposure. Given that UVR8 is present across plant organs and tissues, knowledge of the systemic signalling involved in its activation and function throughout the plant is important for understanding the context of specific responses. Fine-scale understanding of both UV-B irradiance and perception within tissues and cells requires improved application of knowledge about UV-attenuation in leaves and canopies, warranting greater consideration when designing experiments. In this context, reciprocal crosstalk among photoreceptor-induced pathways also needs to be considered, as this appears to produce particularly complex patterns of physiological and morphological response. Through crosstalk, plant responses to UV-B radiation go beyond simply UV-protection or amelioration of damage, but may give cross-protection over a suite of environmental stressors. Overall, there is emerging knowledge showing how information captured by UVR8 is used to regulate molecular and physiological processes, although understanding of upscaling to higher levels of organisation, i.e. organisms, canopies and communities remains poor. Achieving this will require further studies using model plant species beyond Arabidopsis, and that represent a broad range of functional types. More attention should also be given to plants in natural environments in all their complexity, as such studies are needed to acquire an improved understanding of the impact of climate change in the context of plant-UV responses. Furthermore, broadening the scope of experiments into the regulation of plant-UV responses will facilitate the application of UV radiation in commercial plant production. By considering the progress made in plant-UV research, this perspective highlights prescient topics in plant-UV photobiology where future research efforts can profitably be focussed. This perspective also emphasises burgeoning interdisciplinary links that will assist in understanding of UV-B effects across organisational scales and gaps in knowledge that need to be filled so as to achieve an integrated vision of plant responses to UV-radiation.

Linkages between stratospheric ozone, UV radiation and climate change and their implications for terrestrial ecosystems.

Exposure of plants and animals to ultraviolet-B radiation (UV-B; 280-315 nm) is modified by stratospheric ozone dynamics and climate change. Even though stabilisation and projected recovery of stratospheric ozone is expected to curtail future increases in UV-B radiation at the Earth's surface, on-going changes in climate are increasingly exposing plants and animals to novel combinations of UV-B radiation and other climate change factors (e.g., ultraviolet-A and visible radiation, water availability, temperature and elevated carbon dioxide). Climate change is also shifting vegetation cover, geographic ranges of species, and seasonal timing of development, which further modifies exposure to UV-B radiation. Since our last assessment, there has been increased understanding of the underlying mechanisms by which plants perceive UV-B radiation, eliciting changes in growth, development and tolerances of abiotic and biotic factors. However, major questions remain on how UV-B radiation is interacting with other climate change factors to modify the production and quality of crops, as well as important ecosystem processes such as plant and animal competition, pest-pathogen interactions, and the decomposition of dead plant matter (litter). In addition, stratospheric ozone depletion is directly contributing to climate change in the southern hemisphere, such that terrestrial ecosystems in this region are being exposed to altered patterns of precipitation, temperature and fire regimes as well as UV-B radiation. These ozone-driven changes in climate have been implicated in both increases and reductions in the growth, survival and reproduction of plants and animals in Antarctica, South America and New Zealand. In this assessment, we summarise advances in our knowledge of these and other linkages and effects, and identify uncertainties and knowledge gaps that limit our ability to fully evaluate the ecological consequences of these environmental changes on terrestrial ecosystems.

UV Screening in Native and Non-native Plant Species in the Tropical Alpine: Implications for Climate Change-Driven Migration of Species to Higher Elevations.

Ongoing changes in Earth's climate are shifting the elevation ranges of many plant species with non-native species often experiencing greater expansion into higher elevations than native species. These climate change-induced shifts in distributions inevitably expose plants to novel biotic and abiotic environments, including altered solar ultraviolet (UV)-B (280-315 nm) radiation regimes. Do the greater migration potentials of non-native species into higher elevations imply that they have more effective UV-protective mechanisms than native species? In this study, we surveyed leaf epidermal UV-A transmittance (TUV A) in a diversity of plant species representing different growth forms to test whether native and non-native species growing above 2800 m elevation on Mauna Kea, Hawaii differed in their UV screening capabilities. We further compared the degree to which TUV A varied along an elevation gradient in the native shrub Vaccinium reticulatum and the introduced forb Verbascum thapsus to evaluate whether these species differed in their abilities to adjust their levels of UV screening in response to elevation changes in UV-B. For plants growing in the Mauna Kea alpine/upper subalpine, we found that adaxial TUV A, measured with a UVA-PAM fluorometer, varied significantly among species but did not differ between native (mean = 6.0%; n = 8) and non-native (mean = 5.8%; n = 11) species. When data were pooled across native and non-native taxa, we also found no significant effect of growth form on TUV A, though woody plants (shrubs and trees) were represented solely by native species whereas herbaceous growth forms (grasses and forbs) were dominated by non-native species. Along an elevation gradient spanning 2600-3800 m, TUV A was variable (mean range = 6.0-11.2%) and strongly correlated with elevation and relative biologically effective UV-B in the exotic V. thapsus; however, TUV A was consistently low (3%) and did not vary with elevation in the native V. reticulatum. Results indicate that high levels of UV protection occur in both native and non-native species in this high UV-B tropical alpine environment, and that flexibility in UV screening is a mechanism employed by some, but not all species to cope with varying solar UV-B exposures along elevation gradients.

Investigation of the role of environmental contamination in the occurrence of residues of the veterinary drug phenylbutazone in cattle.

Phenylbutazone is a non-steroidal anti-inflammatory drug licensed for use in horses to treat musculoskeletal disorders. It is not permitted in the European Union for use in animals destined for the food chain. Official statistics provided by the European Food Safety Authority (EFSA) show that 0.18% of bovines tested in the European Union between 2008 and 2014 for non-steroidal anti-inflammatory drugs were non-compliant, with phenylbutazone representing over 28% of these. Anecdotal evidence suggests animals that have not been treated with the drug may have produced non-compliant samples, possibly through some form of contamination. In this study, ultra-high-performance liquid chromatography coupled with mass-spectrometric detection was applied to bovine plasma samples to determine if detectable residues (CCα = 0.28 ng ml-1) may occur in untreated animals as a result of environmental contamination through normal farming practice. The study demonstrates that waste from animals treated with phenylbutazone, and spread on an area of pasture, can contaminate untreated bovines grazing the pasture many weeks later. It was determined that this contamination, which can persist over a significant period, may be due to the ingestion of as little as 30 µg phenylbutazone by a 500 kg bullock.

High-resolution mass spectrometry analysis of tetrodotoxin (TTX) and its analogues in puffer fish and shellfish.

Tetrodotoxin (TTX) is an emerging toxin in the European marine environment. It has various known structural analogues. It acts as a sodium channel blocker; the ability of each analogue to bind to the sodium channel varies with the particular structure of each analogue. Thus, each analogue will vary in its toxic potential. TTX analogues co-occur in food samples at variable concentrations. An LC-MS method was developed for the identification and quantitation of several analogues of TTX using an LTQ-Orbitrap XL mass spectrometer. The LTQ-Orbitrap XL mass spectrometer facilitates high mass accuracy measurement up to 100,000 full width at half maximum (FWHM). Using high resolution at 100,000 FWHM allows for the identification of TTX and its analogues in various matrices, including puffer fish and molluscan shellfish samples (Δ ppm = 0.28-3.38). The confirmation of characteristic fragment ions of TTX and its analogues was achieved by determining their elemental formulae via high mass accuracy. A quantitative method was then developed and optimised using these characteristic fragment ions. The limit of quantitation (LOQ) of the method was 0.136 µg g(-1) (S/N = 10) and the limit of detection (LOD) was 0.041 µg g(-1) (S/N = 3) spiking TTX standard into TTX-free mackerel fish extracts. The method was applied to naturally contaminated puffer fish and molluscan shellfish samples to confirm the presence of TTX and its analogues.