Sunlight Exposure Research Articles

Exploring the post-illumination behavior of 1D/2D-NiMoO4/Bi2O2CO3 heterostructure photocatalyst: Insights into the photocatalytic 'memory effect'

Photocatalysts with a "memory" effect can regain their activity after light is removed. We developed a novel NiMoO4/Bi2O2CO3 hybrid photocatalyst through a simple hydrothermal process. This memory effect results from the trapping and release of photogenerated electrons, facilitated by the NiMoO4/Bi2O2CO3 hybrid's compatible band structures and internal electrostatic field, which enhance electron transfer. This photocatalyst effectively removes Rhodamine B (RhB), with a 34 % increase in oxidation after sunlight exposure. The optimized NiMoO4/Bi2O2CO3 composite achieves 84 % photocatalytic degradation of RhB (kapp = 0.0196 min−1) under visible light in 90 min, proving effective for water pollutant removal both during and after light exposure.

Facile synthesis, morphological, optical, catalytic and photocatalytic properties of Ag nanoparticles decorated Ce doped ZnO hybrid plasmonic nanorods

Designing plasmonic metal–semiconductor hybrid nanostructures for photodecomposition of industrial textile effluent has been considered as a great way to boost the catalytic and photocatalytic capability by promoting effective separation of photoexcited charge carriers. Herein, fabrication of Ag nanoparticles decorated Ce doped ZnO nanostructures were demonstrated via facile wet chemical method. The morphology and structure of the fabricated photocatalysts were analysed using FESEM, XRD and Raman spectroscopy whereas PL, TRPL and UV–vis absorption spectroscopy were employed to examine their optical behaviour. Catalytic response of the synthesized catalysts was studied for 4-NP to 4-AP reduction and the results are more favourable for Ag loaded Ce doped ZnO catalysts and achieved 96.4 % reduction of 4-NP in only 4 min. Photocatalytic measurements showed that higher Ag NP loading onto Ce doped ZnO nanostructures led to superior photodegradation ability over other photocatalysts for the degradation of synthetic dyes and levofloxacin antibiotic. The sunlight driven photodecolorization of harmful synthetic dyes and levofloxacin were studied and efficacy of 97.5, 97.1, 85.1, and 70.9 % were achieved for MG, MB, RhB and MO dyes, respectively in 12 min and 97.2 % efficiency for degradation of levofloxacin was achieved in 20 min of sunlight exposure. Furthermore, the key reactive species was identified and tentative photodegradation process was explained. This work provides an excellent plasmonic-semiconductor catalyst and photocatalyst with good photostability and practical applicability indicating its enormous potential for application in environmental remediation.

Multi-Objective Optimization of a Folding Kinetic Facade System Proposal for Thermal, Daylight, and Energy Performances

Efficient utilization of daylight and energy resources significantly influences the quality of indoor spaces, user comfort, and overall efficiency. This study presents a folding facade proposal through the design alternatives offered by kinetic architecture and parametric design to enhance efficiency. This alternative design method integrates and coordinates the design components simultaneously and makes any intervention easier when compared with traditional design methods. In this context, the method is based on computational models, aiming to find the most efficient design alternative by optimization. The proposed facade design specifically targets an indoor office space within a university. The modular system, integrated into existing windows, facilitates a folding movement. This dynamic feature aims to optimize illumination within the space, effectively controlling daylight without causing disruptions to users. Simultaneously, the design seeks to balance energy consumption and ensure thermal comfort. The results show that it provides a significant improvement over the base case. The proposed kinetic façade system improved indoor thermal comfort by 22.09-31.99% while slightly increasing energy use (2% at most). Although it provided an average of 59% improvement in spatial Daylight Autonomy (sDA), 13.30% - 87.38% was achieved compared to the base case. However, the desired value by LEED was achieved very little in Annual Sunlight Exposure (ASE). In conclusion, the proposed kinetic facade system proves to be a valuable intervention for enhancing the indoor environment of an office space at Dokuz Eylül University

Piper chaba Stem Extract Assisted Facile Synthesis of Zinc Oxide Nanoparticles for Photocatalytic and Antimicrobial Applications

ABSTRACTThe versatile application of metal‐based nanoparticles has led to a recent rise in interest in the low‐cost and eco‐friendly green chemistry‐based development of metal oxide nanoparticles. This work focuses on the photocatalytic and antibacterial uses of the zinc oxide nanoparticles (ZnONPs) that were produced based on a green approach employing stem extract of Piper chaba. The formation of ZnONPs was preliminary validated by the appearance of an absorption band at 373 nm and a stretching band due to ZnO at 480 cm−1 in UV–Vis and FTIR spectrum, respectively. The crystalline nature of ZnONPs with a hexagonal wurtzite phase and an average crystallite size of 25 nm was validated by XRD analysis. ZnONPs' crystalline nature was further supported by TEM, which further showed that they were mostly cubic in form and had an average length of 30 nm. Synthesized ZnONPs demonstrated significant antibacterial activity against Salmonella typhi, Vibrio cholerae, Escherichia coli, and Staphylococcus aureus and lucrative photocatalytic activity with the rate constant value of 0.0273 min−1 towards the degradation of methylene blue under sunlight exposure. Therefore, a facile, affordable, and ecologically sustainable method like this might be used for the large‐scale synthesis of ZnONPs.

Green nanoarchitectonics Ce-Co₃O₄/BiVO₄ (p-n) heterojunction nanocomposite: Dual functionality for photodegradation of Congo red and supercapacitor applications

In this work, we synthesised a new Ce-doped Co₃O₄/BiVO₄ heterojunction photocatalyst by a green synthesis strategy utilizing Magnifera indica leaf extract for Co₃O₄ and a precipitation method for pure BiVO₄. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), UV–Visible diffuse reflectance spectroscopy (UV-DRS), Brunauer-Emmett-Teller (BET) surface area analysis, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV) were used to investigate the material's structural, optical The Ce-Co₃O₄/BiVO₄ heterojunction decreased the band gap energy to 1.92 eV, resulting in increased visible light absorption. The photocatalytic activity of the developed heterojunction was evaluated by degrading the anionic dye Congo red (CR) under different circumstances such as pH, catalyst dose, dye concentration, and irradiation period. At pH 4, 98 % degradation was obtained using a dye concentration of 50 ppm, a catalyst dose of 40 mg, and 50 min of sun light exposure. High-resolution mass spectrometry (HR-MS) validated the effective degradation of CR and offered information on the potential degradation process. Kinetic investigations revealed that the photodegradation of CR followed a pseudo-first-order kinetic model. This study demonstrates the effectiveness of Ce-Co₃O₄/BiVO₄ heterojunctions in photocatalytic applications, namely for the removal of dye contaminants from wastewater using visible light. Furthermore, the heterojunction showed a substantial rise in specific capacitance, reaching 1353 F/g, 5.4 times that of pure Co3O4. The Nyquist plot displayed a smaller arc radius, indicating improved electrochemical characteristics and a possible application as a semiconductor. These results highlight the Ce-Co₃O₄/BiVO₄ heterojunction as a promising photocatalyst with outstanding dye degrading capabilities and increased electrochemical performance, appropriate for diverse environmental and energy storage applications.

Influence of daylight on real estate housing prices. A multiple regression model application in Turin

Daylight is crucial in architecture, influencing human health, well-being, energy efficiency, and the post-COVID-19 perception of residential spaces. People often consider daylight among the most important features when buying a home, which potentially affects real estate asset pricing. Within this framework, this study explored the impact of daylight on real estate asset pricing, particularly focusing on its role in the Italian market. The research employed two approaches: (i) simulations of 100 units to determine a large set of daylight metrics and (ii) a statistical approach, applying Hedonic Analysis principles to investigate how house attributes influence pricing. A data sample of 100 housing units was selected in Turin (Italy), including variables such as location, floor area, construction year, façade type, and daylight metrics. By using Multiple Regression Analysis, after Exploratory Analysis and outlier management, we identified significant variables influencing housing listing prices, such as energy class, conservation status, elevator presence, terraces/balconies, and frame type. Notably, two daylight metrics (annual sunlight exposure and useful daylight illuminance) were found to be significant, while others, like average daylight factor and spatial daylight autonomy, were not. The final model was validated by means of a control sample, demonstrating the relevance of daylight in real estate pricing. This research contributes to the literature, providing an in-depth exploration of the impact of daylight on hedonic analysis in a relatively underexplored research space. Precisely, the work contributes to bridging the literature gap about the detection of the influence of daylight on real estate market pricing processes by means of regression analysis.

Generation of Microplastics from Biodegradable Packaging Films Based on PLA, PBS and Their Blend in Freshwater and Seawater.

Biodegradable polymers and their blends have been advised as an eco-sustainable solution; however, the generation of microplastics (MPs) from their degradation in aquatic environments is still not fully grasped. In this study, we investigated the formation of bio-microplastics (BMPs) and the changes in the physicochemical properties of blown packaging films based on polylactic acid (PLA), polybutylene succinate (PBS) and a PBS/PLA 70/30 wt% blend after degradation in different aquatic media. The tests were carried out in two temperature/light conditions to simulate degradation in either warm water, under sunlight exposure (named Warm and Light-W&L), and cold deep water (named Cold and Dark-C&D). The pH changes in the aqueous environments were evaluated, while the formed BMPs were analyzed for their size and shape alongside with variations in polymer crystallinity, surface and mechanical properties. In W&L conditions, for all the films, the hydrolytic degradation led to the reorganization of the polymer crystalline phases, strong embrittlement and an increase in hydrophilicity. The PBS/PLA 70/30 blend exhibited increased resistance to degradation with respect to the neat PLA and PBS films. In C&D conditions, no microparticles were observed up to 12 weeks of degradation.

Rosacea in East Asian populations: Clinical manifestations and pathophysiological perspectives for accurate diagnosis.

Rosacea is a chronic inflammatory disorder primarily affecting the facial skin, prominently involving the cheeks, nose, chin, forehead, and periorbital area. Cutaneous manifestations encompass persistent facial erythema, phymas, papules, pustules, telangiectasia, and flushing. The pathogenesis of rosacea is associated with various exacerbating or triggering factors, including microbial infestation, temperature fluctuations, sunlight exposure, physical exertion, emotional stress, consumption of hot beverages and spicy foods, and exposure to airborne pollen. These environmental factors interact with genetic predispositions in the development of rosacea. The roles of the lipophilic microbiome, ultraviolet radiation, nociceptive responses, and vascular alterations have been proposed as significant factors in the pathogenesis. These insights contribute to understanding the anatomical specificity of facial involvement and the progressive nature of rosacea. East Asian skin, predominantly classified as Fitzpatrick skin phototypes III to IV, is characterized by relatively diminished skin barrier function and increased sensitivity to irritants. Airborne pollen exposure may particularly act as a trigger in East Asian individuals, possibly mediated through toll-like receptors. The lack of specificity in objective clinical and histopathological findings leads to diagnostic challenges for individuals with colored skin, including East Asians, particularly when erythema is the sole objective manifestation. An alternative diagnostic scheme may thus be necessary. A diagnostic approach emphasizing vascular manifestations and nociceptive symptoms potentially holds promise for individuals with darker skin tones. More research focusing on potential variations in skin physiology across different racial groups is essential to establish more effective diagnostic schemes applicable to both dark and light skin colors.

Bismuth Oxychloride Nanoflakes Based Wearable Colorimetric Sensors for Efficient Monitoring of UV Exposure

Ultraviolet radiation from sunlight is essential for human health in many ways such as facilitating vitamin D synthesis while excessive exposure can cause adverse effects such as premature aging, sunburn, and skin cancers. In the USA, between 2007 and 2011, nearly five million adults were treated for skin cancer annually with average treatment costs of $8.1 billion each year. Hence, monitoring daily exposure to sunlight is essential to avoid developing health risks. Colorimetric UV sensors change color as a function of UV exposure, provide onsite information about the level of exposure, and can act as a personal wearable device to assist in making informed decisions on sunlight exposure. These sensors utilize radiation-induced reactions on a dye to produce a color change. We developed a BiOCl based wearable UV sensor for monitoring UV exposure where a white-to-black color transformation is induced due to the creation of oxygen vacancies in BiOCl. This color transformation is not quantifiable in bulk BiOCl; hence BiOCl was purposely dispersed on filter paper to form petal-like nanostructures that help quantify the color change. Four different dye molecules, 6-carboxyfluorescein, 5-carboxyfluorescein, rhodamine-B, and Prussian blue were evaluated, where 6-carboxyfluorescein gave the best color contrast. The sensor responds to UVA, UVB, and UVC and with proper UV filters can be made selective for specific UV radiations. This unique colorimetric UV sensor can help manage personal UV exposure and reduce the risk of sun exposure ailments.Reference: Kyle Troche, Kannan Ramaiyan, Timothy J. Boyle, Fernando H. Garzon, “Bismuth Oxychloride Nanoflakes Enabled High Sensitivity Colorimetric UV Dosimetry” ACS Appl. Nano. Mater. 2023, 6, 7.

Laboratory-Simulated Photoirradiation Reveals Strong Resistance of Primary Macroplastics to Weathering.

The photodegradation of macroplastics in the marine environment remains poorly understood. Here, we investigated the weathering of commercially available plastics (tabs 1.3 × 4.4 × 0.16 cm), including high-density polyethylene, low-density polyethylene, polypropylene, polystyrene, and polycarbonate, in seawater under laboratory-simulated ultraviolet A radiation for 3-9 months, equivalent to 25-75 years of natural sunlight exposure without considering other confounding factors. After the exposure, the physical integrity and thermal stability of the tabs remained relatively intact, suggesting that the bulk polymer chains were not severely altered despite strong irradiation, likely due to their low specific surface area. In contrast, the surface layer (∼1 μm) of the tabs was highly oxidized and eroded after 9 months of accelerated weathering. Several antioxidant additives were identified in the plastics through low temperature pyrolysis coupled with gas chromatography/mass spectrometry (Pyr-GC/MS) analysis. The Pyr-GC/MS results also revealed many new oxygen-containing compounds formed during photodegradation, and these compounds indicated the dominance of chain scission reactions during weathering. These findings highlight the strong resistance of industrial macroplastics to weathering, emphasizing the need for a broader range of plastics with varying properties and sizes to accurately estimate plastic degradation in the marine environment.

Responses of mustard greens (Brassica juncea L.) to additional lighting duration of LED under greenhouse conditions in the tropical zone

ABSTRACT Light-emitting diodes have been beneficial for plant growth, especially for microgreens in countries with low radiation, greenhouses, and chambers. However, information about how plants respond to additional light-emitting diode lighting after 12 hours of sunlight exposure in tropical areas is limited. This study examines the effects of long-duration light-emitting diodes on mustard greens in Kien Giang province, Vietnam (105°14’33.21” E; 9°91’41.13” N). The trials were conducted in the greenhouse for two growing seasons with a completely randomized design, including 0, 2, 4, and 6 hours of assembled light-emitting diodes lighting and 4 hours of commercial light-emitting diodes lighting after 6 pm, with three replications. Results showed that weather factors in season 2 favorably influenced mustard’s growth. At 4 hours of lighting, commercial light-emitting diodes showed a higher chlorophyll index, flowering time, flowering rate, leaf number, and absolute growth rate of leaf number but less leaf and fresh shoot weight than assembled light-emitting diodes. Four hours of assembled light-emitting diodes positively affected most mustard growth, while 6 hours of assembled light-emitting diodes were superior for flowering aspects. Adding 4 hours of light-emitting diodes could increase leafy yield and shorten the harvesting time of mustard greens grown in greenhouses under tropical conditions.

Harvesting energy horizons: Bifacial PV and reversible fuel cells unite for sustainable building solutions

This study explores the integration of bifacial photovoltaic (PV) panels with proton exchange membrane (PEM) reversible fuel cells (RFC) to enhance renewable energy storage across various U.S. climates. It assesses the impact of environmental variables like sunlight exposure, climate fluctuations, and energy demands on system efficiency and resilience. The cities considered in the study were Tucson, Los Angeles, Denver, Dallas, and Minneapolis. Each city was chosen for its unique climatic characteristics, ranging from the arid heat of Tucson to the cold temperatures of Minneapolis. This diverse selection helps to evaluate the system's performance and economic viability across a broad spectrum of environmental conditions. Economic analysis focuses on metrics such as the Levelized Cost of Electricity (LCOE), Levelized Cost of Hydrogen (LCOH), and Levelized Cost of Storage (LCOS). Findings indicate significant economic benefits through varying bifacial PV gains from 0 to 20% yield with reductions in LCOE by 16%, LCOH by 14%, LCOS by 13%, and overall system LCOE by 18%. The results highlight the potential of bifacial PV and PEM-RFC systems to boost energy yield and economic efficiency amid dynamic environmental conditions. This analytical framework offers detailed insights into the economic viability and advantages of these systems in different climatic zones in the United States.

Does sunlight exposure predict next-night sleep? A daily diary study among U.S. adults.

Poor sleep is becoming increasingly prevalent and is associated with adverse health outcomes. Sunlight exposure may improve sleep by regulating circadian rhythms, increasing vitamin D, and influencing melatonin production. However, research on the sunlight-sleep association is limited, especially outside of cross-sectional designs. This study examined associations between daily self-reported sunlight exposure and next-night sleep quality in 103 adults for up to 70 days. The timing of sunlight exposure predicted next-night sleep quality. Specifically, morning sunlight exposure, relative to no sunlight, predicted better sleep quality based on responses to the brief Pittsburg Sleep Quality Index. Duration of sunlight exposure was generally not associated with sleep quality. Morning sunlight may regulate circadian rhythms, subsequently improving sleep. Findings have potential implications for sleep interventions and daylight savings time policies. Future research should test whether morning sunlight exposure can enhance the effectiveness of sleep interventions.

Exogenous application of salicylic acid and putrescine triggers physiological and biochemical changes in plants to improve growth and bioactive constituents of Ammi majus L

Ammi majus L. is a rich source of coumarins in addition to various flavonoids, alkaloids, and terpenoids. Medicinal products of Ammi majus seed, with sunlight exposure, are worldwide used for the treatment of vitiligo (pale-white patches on the skin). To increase the content of seed-coumarins and to investigate the physiological reasons in this respect, two net-house experiments were conducted using foliar-spray treatments (0, 25, 50, 100 and 200 mg L−1) of salicylic acid (SA) (Experiment 1) and putrescine (PUT) (Experiment 2). All studied parameters were improved due to the foliar application of both growth elicitors (SA and PUT). The best outcomes for SA and PUT were obtained at 50 mg L−1 which maximally increased the growth characteristics, physiological and biochemical attributes, and seed quality parameters. In comparison to the control, 50 mg L−1 of SA and PUT increased the chlorophyll content by 26.3% and 25.5%, carotenoid content by 31.4% and 18.5%. In addition 50 mg L−1 of both SA and PUT gives the best results of FTIR (Fourier Transform Infrared Spectrophotometer) & XRD (X-ray Diffraction) analysis. In GC–MS analysis, 50 mg L−1 of SA and PUT increases the Methoxsalen content (17.44 and 16.81%) and 7H-Furo[3,2-g]. Bown (1995) [1] Benzopyran-7-one, 4,9-dimethoxy content(14.92 and 13.93%) and p-camphorene content (13.11 and 12.27%) in contrast to the control. Other important constituents were Pimpinellin (6.31 and 4.08%), Bergapten (8.72 and 6.220, Isospathulenol (7.80 and 2.47), Octadecenoic acid (5.78 and 3.59) and Vitamin E (1.48 and 0.16).

Impact of overhead evaporative cooling, canopy location, sunlight exposure, inoculation level, region, and growing season on the survival of generic Escherichia coli on in-field Fuji apples.

The survival of inoculated Escherichia coli on Fuji apples in Washington State orchards was studied, considering evaporative cooling, canopy location, year, and region, with the examination of sunlight exposure and inoculation levels in year 2. Rifampicin-resistant E. coli was applied to Fuji apples. Initial concentrations for the high-inoculation study were 7.4±0.3 log10 CFU per apple and 3.4±0.3 log10 CFU per apple for the low-inoculation study. Enumeration of E. coli was conducted at 0, 2, 10, 18, 34, 42, 58, 82, 106, and 154 h after inoculation. Results were analyzed using Tukey's honest significance difference test and a log-linear model. Log-linear, Weibull, and biphasic models characterized E. coli die-off patterns for high and low inoculations. The application of evaporative overhead cooling water did not significantly influence E. coli survival on Fuji apples; inoculation level and sunlight exposure were significant factors in a log-linear model. Escherichia coli decreased by 5.5±1.3 and 3.3±0.4 log10 CFU per apple for high and low-inoculated apples, respectively, by 154 h. The biphasic model best explained the die-off pattern for high and low-inoculated Fuji apples. Overhead evaporative cooling, a useful fruit quality practice, did not impact the survival of generic E. coli on Fuji apple surfaces. The significant impact of sunlight exposure and inoculation levels on die-off highlights the importance of ultraviolet radiation in risk reduction and the need for various inoculum concentrations in preharvest field studies.

Emerging role of vitamin D deficiency as a risk factor for retinal venous occlusions and need for public health measures for its prevention.

To estimate levels of serum vitamin D in patients of retinal vein occlusion (RVO) and compare with age- and sex-matched controls. A prospective case-control study of 54 patients of RVO and 54 age- and sex-matched attendants of patients presenting to a tertiary care hospital in Delhi was performed. Patients on vitamin D supplementations and RVO due to infective or immunological causes or patients of glaucoma were excluded. Serum vitamin D levels of all the study participants along with relevant blood investigations with history and examination were documented. Vitamin D deficiency was defined as <20 ng/ml. The mean serum vitamin D levels seen in RVO patients and the control group were 14.19 ± 5.23 ng/ml and 19.42 ± 10.27 ng/ml, respectively (P value = 0.001) with an odds ratio of 10.558 (CI = 2.34-47.50), indicating vitamin D deficiency to be strongly correlated with RVO. Maximum patients of RVO (46.3%) were seen during the winter season. The study noted hypertension [odds ratio 20.22 (CI = 5.812-70.347)], dyslipidemia, and anemia [odds ratio 4.107 (CI = 0.62-26.90)] to be the risk factors for RVO as previously proved in the literature. Smoking, diabetes, alcohol intake, and body mass index did not emerge as risk factors for RVO. Vitamin D deficiency is associated with RVO; hence, estimation of serum vitamin D levels should be advised as a part of routine investigations while looking for the cause of RVOs. Public health measures like food fortification with vitamin D micronutrients and public awareness towards increased sunlight exposure in the community are simple, inexpensive measures that can decrease the burden of sight-threatening disease of RVO in the community.

Seasonality and sun exposure in incidence of major depression, bipolar disorder, and first-time use of antidepressant medication

Introduction Seasonality in depressive and bipolar disorders, are recognized in the ICD-10/11 and DSM-5 diagnostic systems. The existence of a seasonal pattern of hospital diagnosis of major depression, bipolar disorder and prescription of antidepressant medications has not been evaluated in the Danish population. Methods We retrieved date and year for all first-time hospital contacts with depression or bipolar disorder between 1999 and 2019, registered in the Danish National Patient Registry. Depression was defined using the ICD-10 F32-F33 codes, and for bipolar disorder the F30 or F31 codes. Date and year of all first-time purchases of antidepressant medications with ATC codes (N06A) between 1999 and 2021 were retrieved from the Danish National Prescription Registry, containing information on all prescribed drugs dispensed at pharmacies since 1995. Data on sunlight hours from 2012 to 2021 were retrieved from the Danish Metrological Institute. Results Incidences of hospital diagnoses as well as purchases of medication varied with month and season. The monthly variations were larger for antidepressant medication and smallest for bipolar disorder. The multiple linear regression analysis showed that number of first-time diagnoses of depression or bipolar disorder did not correlate with season. For antidepressant medication the number of first-time prescriptions was significantly lower in summer compared to the winter season. Conclusion This study found a seasonal variation of first-time prescriptions of antidepressant medication. We did not find a seasonal variation in first-time hospital diagnoses. Further research looking into depression severity, polarity of bipolar illness episodes, lag-time for sunlight exposure, and specific parts of the yearly photoperiods should be conducted.

An investigation into the aging mechanism of disposable face masks and the interaction between different influencing factors

In the natural environment, a symphony of environmental factors including sunlight exposure, current fluctuations, sodium chloride concentrations, and sediment dynamics intertwine, potentially magnifying the impacts on the aging process of disposable face masks (DFMs), thus escalating environmental risks. Employing Regular Two-Level Factorial Design, the study scrutinized interactive impacts of ultraviolet radiation, sand abrasion, acetic acid exposure, sodium chloride levels, and mechanical agitation on mask aging. Aging mechanisms and environmental risks linked with DFMs were elucidated through two-dimensional correlation analyses and risk index method. Following a simulated aging duration of three months, a single mask exhibited the propensity to release a substantial quantity of microplastics, ranging from 38,800 ± 360 to 938,400 ± 529 particles, and heavy metals, with concentrations from 0.06 ± 0.02 μg/g (Pb) to 29.01 ± 1.83 μg/g (Zn). Besides, specific contaminants such as zinc ions (24.24 μg/g), chromium (VI) (4.20 μg/g), thallium (I) (0.92 μg/g), tetracycline (0.51 μg/g), and acenaphthene (1.73 μg/g) can be adsorbed significantly by aged masks. The study elucidates pivotal role of interactions between ultraviolet radiation and acetic acid exposure in exacerbating the environmental risks associated with masks, while emphasizing the pronounced influence of many other interactions. The research provides a comprehensive understanding of the intricate aging processes and ensuing environmental risks posed by DFMs, offering valuable insights essential for developing sustainable management strategies in aquatic ecosystems.

Screening the release of chemicals and microplastic particles from diverse plastic consumer products into water under accelerated UV weathering conditions

Photodegradation of plastic consumer products is known to accelerate weathering and facilitate the release of chemicals and plastic particles into the aquatic environment. However, these processes are complex. In our presented pilot study, eight plastic consumer products were leached in distilled water under strong ultraviolet (UV) light simulating eight months of Central European climate and compared to their respective dark controls (DCs). The leachates and formed plastic particles were exploratorily characterized using a range of chemical analytical tools to describe degradation and leaching processes. These techniques covered (a) microplastic analysis, showing substantial liberation of plastic particles further increased under UV exposure, (b) non-targeted mass spectrometric characterization of the leachates, revealing several hundreds of chemical features with typically only minor agreement between the UV exposure and the corresponding DCs, (c) target analysis of 71 organic analytes, of which 15 could be detected in at least one sample, and (d) metal(loid) analysis, which revealed substantial release of toxic metal(loid)s further enhanced under UV exposure. A data comparison with the US-EPA’s ToxVal and ToxCast databases showed that the detected metals and organic additives might pose substantial health and environmental concerns, requiring further study and comprehensive impact assessments.

Environmental impact of the variations in solar reflectance index values of some selected dimension stones due to cyclic thermal shock

Natural stones are widely used environmentally appropriate building materials as dimension stone both for exterior cladding and floor coverings in urban areas. Depending on their solar reflectivity, these materials may absorb more solar radiation, especially with noontime summer sunlight exposure, which may cause both increasing cooling costs in commercial buildings and overheating of a city with the formation of urban heat islands. Solar reflectance index (SRI) is defined as the ability of a surface to reject solar heat which tends to change with physical, chemical and biological degradation processes by varying solar reflectance (SR) and thermal emissivity (TE) values. Weakening of the stone matrix structure by physical degradation mechanism, such as thermal shock (T-S) cycles mostly have significant impact on SRI. Within the scope of this study, SRI values were calculated before and after cyclic T-S by measuring the optical properties such as SR and TE values of 30 selected sedimentary and metamorphic originated carbonate-based natural stone types. The changes in surface properties such as color, roughness, and gloss, that may have an impact on the SRI values were also analyzed. In addition, a multivariate regression analysis was established to predict SRI value from such properties with a high degree of accuracy. Finally, it was found that, initial SRI values of 9 natural stone types (mostly metamorphic originated) have been increased considerably by cyclic T-S and tend to increase their ability to reduce urban temperatures by higher SRI values, one of the most important selection criteria in energy consumption for natural stones.