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.

Effect of household cooking on the retention of vitamin D2 and 25-hydroxyvitamin D2 in pulse UV-irradiated, air-dried button mushrooms (Agaricus bisporus).

Vitamin D deficiency has widespread global prevalence. Fresh mushrooms exposed to ultraviolet (UV) radiation generate vitamin D2 which remains after drying. It is not clear if vitamin D2 is retained after rehydration and cooking of dried mushrooms. The aim of this study was to determine the true retention of both vitamin D2 and 25-hydroxyvitamin D2 (25(OH)D2) after cooking UV-irradiated, air-dried, then rehydrated button mushrooms (Agaricus bisporus). Mushrooms were exposed to pulsed UV radiation, then air-dried in a convection oven, followed by rehydration in warm water. Samples were cooked in three different ways: frying (5 min), baking (10 min, 200 °C) and boiling (20 min, 90 °C). Compared to rehydrated, uncooked controls, there was a high retention of D vitamers (≥95%) after cooking. Frying and baking resulted in significantly higher vitamin D2 retention compared to boiling (p < 0.0001). UV-irradiated, dried mushrooms are a valuable source of vitamin D2 after rehydration and cooking.

The Retention of Vitamin D2 and 25-Hydroxyvitamin D2 in Pulse UV-Irradiated Dried Button Mushrooms (Agaricus bisporus) after 12 Months of Storage.

Fresh mushrooms exposed to ultraviolet (UV) radiation prior to drying generate high concentrations of vitamin D2. The aim of this study was to determine the retention of D vitamers in mushrooms that were pulse UV irradiated, then air dried, and stored for up to 12 months. Fresh button mushrooms (A. bisporus) were exposed to pulsed UV radiation (dose 200 mJ/cm2, peak of 17.5 W/cm2), air dried and vacuum sealed before being stored in the dark at room temperature. After storage, samples were freeze dried and quantified for D vitamers using triple quadrupole mass spectrometry. After 3, 6 and 12 months of storage, there was 100% (11.0 ± 0.8 µg/g dry weight (DW), 93% (10.1 ± 0.6 µg/g DW) and 58% (5.5 ± 0.6 µg/g DW) retention of vitamin D2 and 88% (0.14 ± 0.01 µg/g DW), 71% (0.11 ± 0.01 µg/g DW) and 68% (0.1 ± 0.01 µg/g DW) retention of 25-hydroxyvitamin D2 (25(OH)D2), respectively. Compared to the irradiated dried mushrooms that were not stored, the D vitamer concentration was statistically significantly lower (p < 0.05) at 6 and 12 months for 25(OH)D2 and at 12 months for vitamin D2. Sufficient vitamin D2 (99 µg) remained after 12 months storage to provide at least 100% of daily dietary vitamin D requirements in a 20 g serving.

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.

Monetizing environmental impact of integrated aquaponic farming compared to separate systems.

Aquaponics is an emerging industry promoted as a sustainable agricultural practice. Economic sustainability of aquaponics is challenging, partly because some of the benefits are external to the grower, necessitating public intervention to support the industry. We used life cycle assessment to estimate the environmental impact of a proposed aquaponic system and applied a set of economic valuation methods to assess the costs of identified impact factors. We found that the system, planned to produce 60,000 ornamental fish and 108,000 lettuce heads per year would impact the environment with a cost of 10,700 EUR annually, about half the environmental cost of separate production of the same produce. Most of the external cost can be attributed to the industrial processes that prepare products used for aquaponic production. Although this method provides only a rough estimate of actual system impact, it can potentially be used to assess the cost-effectiveness of aquaponics from an environmental perspective.

Consumer preferences for aquaponics: A comparative analysis of Australia and Israel.

Aquaponics, the combined rearing of fish and hydroponic horticulture, has great potential for sustainable food production. Despite increasing research and investments in commercial scale systems, aquaponics is not yet a successful industry and most businesses report negative returns. Aquaponic produce is thought to contain added value to the consumer, and the environment. As most consumers are unaware of aquaponics and their benefits, little is known of its potential market. The present study addresses this gap by analysing willingness to consume aquaponic produce at different price levels in Israel and Australia. We used econometric tools to study the effects of pricing and other factors on revenues in each country. Cluster analysis was used to define groups of potential consumers. The results indicate that 17-30% of the population in both Israel and Australia would prefer to consume aquaponic produce once informed of their added value. Revenues at a given premium would be higher in Israel than in Australia, and higher for a leafy green, than for fish. Different segments of the population differed in their willingness to consume aquaponic produce, as well as in their stated motivations when purchasing food. Conclusions highlight the importance of case-specific research on consumer preferences and economic considerations preceding commercial investment in aquaponics.

Identifying knowledge levels of aquaponics adopters.

Aquaponics or the integration of aquaculture and hydroponic farming, is a sustainable food production system that is currently popular more as a hobby rather than on commercial scales. Recent increase in scientific and public interest in aquaponics and its environmental benefits supports research that addresses technical, economic, and legislative barriers to wider adoption of these systems. A successful combination of hydroponics with an aquaculture system requires high levels of knowledge and skill that are not necessarily available to all aquaponic practitioners. In this short communication, we analyzed the results of a worldwide survey of commercial aquaponic growers' statements about their own knowledge base. Most respondents (59%) had some relevant prior knowledge. Surprisingly, many respondents (41%) claimed to have insufficient knowledge of both fish and plants in their first year of operating a commercial aquaponics system. We interpret this as a rough indication that about a third of the new aquaponic businesses are started by entrepreneurs who are not farmers and have no prior training or experience in growing fish or plants. If aquaponics is to become a more widespread commercially viable enterprise and be capable of delivering its environmental benefits, its promotion must consider the importance of prior knowledge held by entrepreneurs entering aquaponics.

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.

A Review of Mushrooms as a Potential Source of Dietary Vitamin D.

When commonly consumed mushroom species are exposed to a source of ultraviolet (UV) radiation, such as sunlight or a UV lamp, they can generate nutritionally relevant amounts of vitamin D. The most common form of vitamin D in mushrooms is D2, with lesser amounts of vitamins D3 and D4, while vitamin D3 is the most common form in animal foods. Although the levels of vitamin D2 in UV-exposed mushrooms may decrease with storage and cooking, if they are consumed before the 'best-before' date, vitamin D2 level is likely to remain above 10 µg/100 g fresh weight, which is higher than the level in most vitamin D-containing foods and similar to the daily requirement of vitamin D recommended internationally. Worldwide mushroom consumption has increased markedly in the past four decades, and mushrooms have the potential to be the only non-animal, unfortified food source of vitamin D that can provide a substantial amount of vitamin D2 in a single serve. This review examines the current information on the role of UV radiation in enhancing the concentration of vitamin D2 in mushrooms, the effects of storage and cooking on vitamin D2 content, and the bioavailability of vitamin D2 from mushrooms.

Vitamin D Content of Australian Native Food Plants and Australian-Grown Edible Seaweed.

Vitamin D has previously been quantified in some plants and algae, particularly in leaves of the Solanaceae family. We measured the vitamin D content of Australian native food plants and Australian-grown edible seaweed. Using liquid chromatography with triple quadrupole mass spectrometry, 13 samples (including leaf, fruit, and seed) were analyzed in duplicate for vitamin D2, vitamin D3, 25-hydroxyvitamin D2, and 25-hydroxyvitamin D3. Five samples contained vitamin D2: raw wattleseed (Acacia victoriae) (0.03 µg/100 g dry weight (DW)); fresh and dried lemon myrtle (Backhousia citriodora) leaves (0.03 and 0.24 µg/100 g DW, respectively); and dried leaves and berries of Tasmanian mountain pepper (Tasmannia lanceolata) (0.67 and 0.05 µg/100 g DW, respectively). Fresh kombu (Lessonia corrugata) contained vitamin D3 (0.01 µg/100 g DW). Detected amounts were low; however, it is possible that exposure to ultraviolet radiation may increase the vitamin D content of plants and algae if vitamin D precursors are present.

The Nutritional and Phytochemical Composition of the Indigenous Australian Pindan Walnut (Terminalia cunninghamii) Kernels.

Nutritional composition of the kernels of two types of Pindan walnut (Terminalia cunninghamii), a native nut consumed traditionally by Australian Indigenous peoples, is reported for the first time. Results showed that Pindan walnut kernels contained high levels of fat, protein and ash, approximately 50, 30 and 5% fresh basis, respectively. The levels of minerals in the kernels were much higher than common walnuts and macadamia nuts, especially those of phosphorus, magnesium and zinc. The high amounts of polyphenols in the kernels provided strong hydrophilic antioxidant capacities, of up to 2004 mg Trolox equivalents/100 g fresh basis using the hydrophilic oxygen radical absorbance capacity assay. Both free polyphenol content and hydrophilic antioxidant capacities of the kernels were higher than those of macadamia nuts, although the lipophilic oxygen radical absorbance capacity was lower. These preliminary studies indicate high potential for wider use of the Pindan walnut as a novel, nutritious and health-promoting food.

Phenolic profile and content of sorghum grains under different irrigation managements.

Sorghum grain is widely consumed in Sub-Saharan Africa and Asia, as a staple food due to its adaptation to harsh environments. The impact of irrigation regime: full irrigation (100%); deficit irrigation (50%); and severe deficit irrigation (25%) on phenolic profile and content of six sorghum grain genotypes was investigated by high performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESI-MS). A total of 25 individual polyphenols were unequivocally or tentatively identified. Compared to the colored-grain genotypes, the white grained sorghum var. Liberty had a simpler polyphenol profile. The concentrations of the sorghum-specific 3-deoxyanthocyanidins luteolinidin and apigeninidin, were higher under deficit irrigation compared to the other two regimes in all genotypes. These findings will be valuable for the selection of sorghum genotypes for grain production as human food under water deficit conditions, since polyphenol levels can affect the grain's nutritional value and health properties.

In Pursuit of Vitamin D in Plants.

Vitamin D deficiency is a global concern. Much research has concentrated on the endogenous synthesis of vitamin D in human skin following exposure to ultraviolet-B radiation (UV-B, 280-315 nm). In many regions of the world there is insufficient UV-B radiation during winter months for adequate vitamin D production, and even when there is sufficient UV-B radiation, lifestyles and concerns about the risks of sun exposure may lead to insufficient exposure and to vitamin D deficiency. In these situations, dietary intake of vitamin D from foods or supplements is important for maintaining optimal vitamin D status. Some foods, such as fatty fish and fish liveroils, certain meats, eggs, mushrooms, dairy, and fortified foods, can provide significant amounts of vitamin D when considered cumulatively across the diet. However, little research has focussed on assessing edible plant foods for potential vitamin D content. The biosynthesis of vitamin D in animals, fungi and yeasts is well established; it is less well known that vitamin D is also biosynthesised in plants. Research dates back to the early 1900s, beginning with in vivo experiments showing the anti-rachitic activity of plants consumed by animals with induced rickets, and in vitro experiments using analytical methods with limited sensitivity. The most sensitive, specific and reliable method for measuring vitamin D and its metabolites is by liquid chromatography tandem mass spectrometry (LC-MS/MS). These assays have only recently been customised to allow measurement in foods, including plant materials. This commentary focuses on the current knowledge and research gaps around vitamin D in plants, and the potential of edible plants as an additional source of vitamin D for humans.

Changes in whole grain polyphenols and antioxidant activity of six sorghum genotypes under different irrigation treatments.

Sorghum grain containing elevated polyphenolic antioxidant content may provide foods with benefits to human health. A study was undertaken to determine the potential role of irrigation on the content of polyphenols and antioxidant levels in sorghum grain. Bound, free and total polyphenols were investigated in six diverse sorghum genotypes grown under either full irrigation or a deficit irrigation regime. Results showed genotype, irrigation and their interaction had a significant effect on polyphenols and antioxidant activity (P⩽0.05). The deficit irrigation treatment significantly increased polyphenol content and antioxidant activity compared to the full irrigation treatment. Of the six genotypes Shawaya black short 1 and IS1311C (brown) showed the highest polyphenols levels and antioxidant activity. Therefore, both irrigation treatments and genotype need to be considered by sorghum breeders and farmers during sorghum production to produce grain with the required levels of polyphenolics and antioxidant activity for targeted end-use.

Sources, fates, toxicity, and risks of trifluoroacetic acid and its salts: Relevance to substances regulated under the Montreal and Kyoto Protocols.

Trifluoroacetic acid (TFA) is a breakdown product of several hydrochlorofluorocarbons (HCFC), regulated under the Montreal Protocol (MP), and hydrofluorocarbons (HFC) used mainly as refrigerants. Trifluoroacetic acid is (1) produced naturally and synthetically, (2) used in the chemical industry, and (3) a potential environmental breakdown product of a large number (>1 million) chemicals, including pharmaceuticals, pesticides, and polymers. The contribution of these chemicals to global amounts of TFA is uncertain, in contrast to that from HCFC and HFC regulated under the MP. TFA salts are stable in the environment and accumulate in terminal sinks such as playas, salt lakes, and oceans, where the only process for loss of water is evaporation. Total contribution to existing amounts of TFA in the oceans as a result of the continued use of HCFCs, HFCs, and hydrofluoroolefines (HFOs) up to 2050 is estimated to be a small fraction (<7.5%) of the approximately 0.2 µg acid equivalents/L estimated to be present at the start of the millennium. As an acid or as a salt TFA is low to moderately toxic to a range of organisms. Based on current projections of future use of HCFCs and HFCs, the amount of TFA formed in the troposphere from substances regulated under the MP is too small to be a risk to the health of humans and environment. However, the formation of TFA derived from degradation of HCFC and HFC warrants continued attention, in part because of a long environmental lifetime and due many other potential but highly uncertain sources.

Effects of Genotype and Growth Temperature on the Contents of Tannin, Phytate and In Vitro Iron Availability of Sorghum Grains.

BACKGROUND: It has been predicted that the global temperature will rise in the future, which means crops including sorghum will likely be grown under higher temperatures, and consequently may affect the nutritional properties. METHODS: The effects of two growth temperatures (OT, day/night 32/21°C; HT 38/21°C) on tannin, phytate, mineral, and in vitro iron availability of raw and cooked grains (as porridge) of six sorghum genotypes were investigated. RESULTS: Tannin content significantly decreased across all sorghum genotypes under high growth temperature (P ≤0.05), while the phytate and mineral contents maintained the same level, increased or decreased significantly, depending on the genotype. The in vitro iron availability in most sorghum genotypes was also significantly reduced under high temperature, except for Ai4, which showed a pronounced increase (P ≤0.05). The cooking process significantly reduced tannin content in all sorghum genotypes (P ≤0.05), while the phytate content and in vitro iron availability were not significantly affected. CONCLUSIONS: This research provides some new information on sorghum grain nutritional properties when grown under predicted future higher temperatures, which could be important for humans where sorghum grains are consumed as staple food.

Growth temperature and genotype both play important roles in sorghum grain phenolic composition.

Polyphenols in sorghum grains are a source of dietary antioxidants. Polyphenols in six diverse sorghum genotypes grown under two day/night temperature regimes of optimal temperature (OT, 32/21 °C and high temperature (HT, 38/21 °C) were investigated. A total of 23 phenolic compounds were positively or tentatively identified by HPLC-DAD-ESIMS. Compared with other pigmented types, the phenolic profile of white sorghum PI563516 was simpler, since fewer polyphenols were detected. Brown sorghum IS 8525 had the highest levels of caffeic and ferulic acid, but apigenin and luteolin were not detected. Free luteolinidin and apigeninidin levels were lower under HT than OT across all genotypes (p ≤ 0.05), suggesting HT could have inhibited 3-deoxyanthocyanidins formation. These results provide new information on the effects of HT on specific polyphenols in various Australian sorghum genotypes, which might be used as a guide to grow high antioxidant sorghum grains under projected high temperature in the future.