Harmful Effects Of Solar Radiation Research Articles

Measuring U.S. consumer sunscreen application at home and online: optimizing our methods to determine sunscreen application thickness for improved environmental emissions estimates

Ultraviolet (UV) filters are chemical ingredients used in sunscreen products to protect the skin from the harmful effects of solar radiation and have come under scrutiny due to concerns of potential aquatic impacts after direct release to the environment. UV filter emissions to the environment are directly influenced by the amount and frequency of sunscreen products applied by consumers. Previous research indicates that consumers have not applied adequate sunscreen thicknesses for several decades. Thus, comprehensive research is needed to investigate a more representative sunscreen application thickness to better estimate UV filter emissions from sunscreen products. A home use study and an online survey was conducted to better estimate sunscreen application thickness potentially exhibited by the general population both during daily skincare routine and when going to the beach. A secondary objective was to further improve the consumer survey method for estimating sunscreen application thickness. During their daily activities, the results of the home usage test suggest that people are applying 0.89 mg/cm2 to their face and 0.85 mg/cm2 to their body on average. Using an online survey to reach a larger sample of the population, the results were higher than the home use study with people applying on average 1.09 and 1.60 mg/cm2 to their face and body, respectively, as part of a regular skincare routine and on average 1.27 and 1.67 mg/cm2 to their face and body, respectively, when planning a day at the beach. The data generated from this study can be used in environmental emissions assessments of UV filters in sunscreen products to provide more realistic and representative estimates. In addition, the online survey instrument developed as part of this research can be used to further investigate sunscreen habits and practices that influence the amount and frequency of sunscreen used by people participating in recreational activities.

Comparison of Various Tree Features for Blocking Solar Radiation in the Arid Urban Environment

In the arid urban environment, pedestrians are often exposed to high amounts of solar radiation during summer, which can limit their activities. Shades are essential for reducing the harmful effects of solar radiation, particularly ultraviolet (UV) rays, which can be dangerous to human health. This study thoroughly evaluated the effect of various tree features for their efficacy in blocking solar radiation, especially photosynthetically active radiation (PAR) and ultraviolet A (UVA). Tree height, trunk height, canopy height and diameter, leaf area index (LAI), leaf size and type, planting techniques (individual and cluster), and agriculture services for eight common tree species used in the Landscape at King Abdulaziz University campus in Jeddah, KSA, were examined. Measurements were taken at noon when the solar zenith angle was perpendicular. The study found that the ability to block PAR and UVA varies based on several factors analyzed. Canopy height and diameter increased a tree's capability to block radiation, with pyramid-shaped trees and simple leaves being the most effective. Higher LAI, cluster planting, and removal of lower branches also increased a tree's radiation-blocking power. In conclusion, shade trees mitigate PAR and UVA and provide pedestrians with more opportunities to enjoy open landscapes in arid regions. KEYWORDS landscape planting, leave index, solar effect, trees benefits, ultraviolet radiation, arid environments

Damaging effects of UVA, blue light, and infrared radiation: in vitro assessment on a reconstructed full-thickness human skin.

Exposure to solar radiation can cause a range of skin damage, including sunburn, erythema, skin carcinogenesis, the release of reactive oxygen species (ROS), inflammation, DNA damage, and photoaging. Other wavelengths beyond UVB, such as UVA, blue light, and infrared radiation, can also contribute to the harmful effects of solar radiation. Reconstructed full-thickness human skin has the potential to serve as effective predictive in vitro tools for evaluating the effects of solar radiation on the skin. The aim of this work was to evaluate the damaging effects of UVA, blue light, and infrared radiation in a full-thickness skin model in terms of viability, inflammation, photoaging, tissue damage, photocarcinogenesis. Full thickness skin models were purchased from Henkel (Phenion FT; Düsseldorf, Germany), and irradiated with increasing doses of UVA, blue light, or infrared radiation. Different endpoints were analyzed on the tissues: Hematoxylin-eosin staining, inflammation mediators, photoaging-related dermal markers and oxidative stress marker GPX1, evaluated by real-time quantitative PCR, as well as photocarcinogenesis markers by Western Blot. The results showed differential responses in cytokine release for each light source. In terms of photoaging biomarkers, collagen, metalloproteinases 1 and 9, elastin, and decorin were modulated by UVA and blue light exposure, while not all these markers were affected by infrared radiation. Furthermore, exposure to UVA and blue light induced loss of fibroblasts and modulation of the photocarcinogenesis markers p53 and p21. In conclusion, the presented results suggest that the various wavelengths of solar light have distinct and differential damaging effects on the skin. Understanding the differential effects of UVA, blue light, and infrared radiation can serve as a valuable tool to investigate the efficacy of photoprotective agents in full thickness skin models.

Obacunone Photoprotective Effects against Solar-Simulated Radiation-Induced Molecular Modifications in Primary Keratinocytes and Full-Thickness Human Skin.

Solar radiation can cause damage to the skin, leading to various adverse effects such as sunburn, reactive oxygen species production, inflammation, DNA damage, and photoaging. To study the potential of photoprotective agents, full-thickness skin models are increasingly being used as in vitro tools. One promising approach to photoprotection involves targeting the redox-sensitive transcription factor Nrf2, which is responsible for regulating various cellular defense mechanisms, including the antioxidant response, inflammatory signaling, and DNA repair. Obacunone, a natural triterpenoid, has been identified as a potent Nrf2 agonist. The present study aims to evaluate the relevance of full-thickness (FT) skin models in photoprotection studies and to explore the potential photoprotective effects of obacunone on those models and in human keratinocytes. Phenion® full-thickness skin models and keratinocytes were incubated with increasing concentrations of obacunone and irradiated with solar-simulated radiation (SSR). Various photodamage markers were evaluated, including histological integrity, oxidative stress, apoptosis, inflammation, photoaging-related dermal markers, and photocarcinogenesis markers. Increasing doses of SSR were found to modulate various biomarkers related to sun damage in the FT skin models. However, obacunone attenuated cytotoxicity, inflammation, oxidative stress, sunburn reaction, photoaging, and photocarcinogenesis in both keratinocytes and full thickness skin models exposed to SSR. These results suggest that obacunone may have potential as a photoprotective agent for preventing the harmful effects of solar radiation on the skin.

Plants from Brazil with Potential Photoprotective Activity: A Review

Background: Skin cancer due the solar radiation is an important public health issue in Brazil. Sunscreen formulations protect the skin from the harmful effects of solar radiation. Plants products can have photoprotective compounds that can be incorporated into sunscreen formulations which attend a demand of society for the use of natural compounds in different cosmetics. This review aims to summarize studies that evaluated the photoprotective activity of plants in Brazil in the last ten years. Materials and Methods: A search was conducted in Medline, Scopus, and Embase databases, using the descriptors Brazilian natural products, photoprotection, natural sunscreen, plant extract, and photoprotective activity. Results: A total of 392 manuscripts were retrieved in the databases searched. After applying the criteria of inclusion and exclusion, thirty-six papers were selected, followed by a final screen resulting in twenty-nine. Plant extracts and oils were tested in these studies. The solar photoprotector factor was determined in vitro in most studies. Only three studies were performed in tests in vivo and there were no clinical studies with an adequate sample effort. Conclusion: Several plant extracts demonstrated promising solar photoprotective activity in vitro, such as Erythrina velutina, Dalbergia monetaria, and Garcinia brasiliensis, which recommend complementary studies for use in sunscreens formulations as most of the studies with Brazilian plants were focused on preliminary analyses in the last decade.

NRF2 in dermo-cosmetic: From scientific knowledge to skin care products.

The skin is the organ that is most susceptible to the impact of the exposome. Located at the interface with the external environment, it protects internal organs through the barrier function of the epidermis. It must adapt to the consequences of the harmful effects of solar radiation, the various chemical constituents of atmospheric pollution, and wounds associated with mechanical damage: oxidation, cytotoxicity, inflammation, and so forth. In this biological context, a capacity to adapt to the various stresses caused by the exposome is essential; otherwise, more or less serious conditions may develop accelerated aging, pigmentation disorders, atopy, psoriasis, and skin cancers. Nrf2-controlled pathways play a key role at this level. Nrf2 is a transcription factor that controls genes involved in oxidative stress protection and detoxification of chemicals. Its involvement in UV protection, reduction of inflammation in processes associated with healing, epidermal differentiation for barrier function, and hair regrowth, has been demonstrated. The modulation of Nrf2 in the skin may therefore constitute a skin protection or care strategy for certain dermatological stresses and disorders initiated or aggravated by the exposome. Nrf2 inducers can act through different modes of action. Keap1-dependent mechanisms include modification of the cysteine residues of Keap1 by (pro)electrophiles or prooxidants, and disruption of the Keap1-Nrf2 complex. Indirect mechanisms are suggested for numerous phytochemicals, acting on upstream pathways, or via hormesis. While developing novel and safe Nrf2 modulators for skin care may be challenging, new avenues can arise from natural compounds-based molecular modeling and emerging concepts such as epigenetic regulation.

The potential of carrot extract as a sunscreen to prevent apoptosis in white mice (Mus musculus) fibroblast cell cultures exposed to UVB light

Introduction: UVB rays are one of the main external factors that play a role in the aging process. Apoptosis of fibroblasts affects skin aging, and the decline in fibroblasts is also caused by the reduced number and ability of growth factors and other hormones. Sunscreen has been used for a long time to protect the skin from the harmful effects of solar radiation, especially UVB rays. Antioxidant activity such as β-carotene and vitamin E from carrots can counteract free radicals and oxidative stress caused by UV radiation. This study aims to test whether in vitro administration of carrot extract can be used as a sunscreen to prevent apoptosis in mouse fibroblast cell cultures exposed to UVB light.
 Method: This research is a laboratory experimental study, using a Randomized Post-test Only Control Group Design. The research sample was fibroblast cell culture derived from the back skin of white mice (Mus Musculus) isolated with Collagenase 1 (primary culture). Observation of fibroblast apoptosis using propidium iodide staining. Data were analyzed using Shapiro-Wilk test, Levene's test, One Way Anova and continued with LSD test. The confidence level in this study is 95%.
 Result: There was a significant difference between the control group and the carrot extract treatment group, but no significant difference was found between the SPF15 group and the carrot group (p>0.01).
 Conclusion: Carrot extract can provide a protective effect on the skin (fibroblasts) and prevent apoptosis.

Natural Organic Ultraviolet Absorbers from Lignin

Excessive exposure of skin to UV-A (315–400 nm) and UV-B (280–315 nm) radiation causes premature skin aging, inflammation, and skin cancers. The harmful effects of solar radiation can be minimized using UV-absorbing agents. Most available organic UV-absorbing agents are synthetic compounds. UV absorbers were developed herein from a reproducible biomass resource, lignin. Lignin is a heterogeneous aromatic polymer with a major absorption maximum in the UV-C (100–280 nm) region but lacks UV-A and UV-B absorption. To produce UV absorbers from lignin, conjugated structures connecting the side chain and aromatic ring must be incorporated to shift the maximum absorption of lignin to the UV-A and UV-B regions. Extensive screening of the degradation reactions of lignin showed that the microwave-assisted alkaline copper oxide reactions yielded lignin-derived monomers and seven dimers with high absorbance in the UV-A and UV-B regions, including the novel compounds 1-(4-hydroxy-3,5-dimethoxyphenyl)-3-(4-hydroxy-3-methoxyphenyl)-2-propen-1-one and 1-(4-hydroxy-3,5-dimethoxyphenyl)-5-(4-hydroxy-3-methoxyphenyl)penta-1,4-dien-3-one. The UV-absorbing compounds have a long conjugated structure comprising aromatic rings and side chains with double bonds and carbonyl groups. The production of UV-A and UV-B absorbing lignin-derived compounds with defined chemical structures from a wide variety of lignified plant biomass sources provides natural UV-absorbing materials with prospects for cosmetics and resin additives.

Sunscreens effectiveness are not altered by concomitant use of moisturizing creams: An ultraviolet reflectance photography study.

Sunscreens are widely used to protect the skin against the harmful effects of solar radiation. It is not known whether solar protection factor of a sunscreen is altered by the concomitant use of other cosmetic products. The aim of this study was to analyze changes in the protective effect of different commercial and ISO standards sunscreens with high SPF applied shortly before and after application of non-sunscreens galenic formulas type moisturizing creams. ISO 24444:2019 standard sunscreens, which claimed SPF 16 and 63, as well as 4 different claimed SPF 50 and 50+ commercial sunscreens were prepared and applied in different sequential order to the back of 25 volunteers and compared with different commercial moisturizing formulas. Ultraviolet (UV) reflectance photography followed by image analysis was used to compare untreated skin and skin treated with moisturizing creams alone and combined with sunscreens. The UV reflectance analysis showed no significant changes of the skin color reflectance treated with moisturizing cream compared with untreated skin. Application of the sunscreen formulations were associated with a 35% - 70% decrease in color related to the in vivo expected SPF, indicating significant UV absorption for all sunscreen formulas. All standard and commercial sunscreens showed no significant differences in UV reflection color level when combined with the different moisturizing creams applied before or after the sunscreen. Effectiveness of low- and high-protection sunscreens were not altered by the concomitant use of a moisturizing creams applied shortly before and after the sunscreens.

Unravelling the Photoprotection Capacity of Resveratrol on Histidine Oxidation

Exposure to sun radiation causes great oxidative stress and activates a numerous of defense mechanisms in living systems, such as the synthesis of antioxidants. Resveratrol (RSV), a naturally occurring stilbene molecule, has antioxidant properties and is synthesized in large amounts when plants are under high oxidative stress. Likewise, under UV and visible radiation, biomolecules are oxidized, losing their physiological properties and, therefore, avoiding the harmful effects of solar radiation is crucial in order to preserve the functionality of cellular components. In proteins, one essential component that is often susceptible to degradation is the amino acid histidine (His), which can be modified via several oxidizing mechanisms. In this article, we evaluate the photoprotection capacity of RSV in photosensitized oxidation of His, which is initiated with a one-electron transfer reaction, yielding the His radical cation (His•+). The photoprotective properties of RSV are evaluated using kinetics analysis during steady-state irradiation and laser flash photolysis experiments. The experimental results reveal that the presence of RSV in the solution causes an evident decrease of the His consumption initial rates as a result of a reaction between His•+ and RSV that recovers the amino acid. In addition, we conclude that during its antioxidant action, RSV is consumed being a sacrificial antioxidant.

A study on an origami-based structure for use as a sun umbrella

Origami art has found numerous engineering applications. Many studies show that folding structures are the source of the desired system characteristics. In this article, we discuss the design of a beach umbrella based on the principles of origami and the study of its optical and mechanical properties. The main requirements for the designed model are that it should reduce the harmful effects of solar radiation on human health, should be compact for storage, and not collapse in the wind. To demonstrate the optical and mechanical properties of the designed model, the developed recursive ray tracing algorithm is used to simulate the propagation of light rays through the designed paper origami-based structure and the numerical simulations are performed using the commercial software ANSYS and LS-DYNA to study the behavior of the designed origami-based structure under lateral forces as well as its folding behavior. A combination of ray tracing approach and an optimization technique based on the genetic algorithm for modifying the developed model is also discussed. Simulation results are presented in the illustrations.

Discovery of a Highly Selective MC1R Agonists Pentapeptide to Be Used as a Skin Pigmentation Enhancer and with Potential Anti-Aging Properties.

One of the first lines of cutaneous defense against photoaging is (a) the synthesis of melanin and (b) the initiation of an oxidative stress response to protect skin against the harmful effects of solar radiation. Safe and selective means to stimulate epidermal pigmentation associated with oxidative stress defense are; however, scarce. Activation of the melanocortin-1 receptor (MC1R) on epidermal melanocytes represents a key step in cutaneous pigmentation initiation and, additionally, it regulates cellular defense mechanisms like oxidative stress and DNA-repair. Thus, making the activation of MC1R an attractive strategy for modulating skin pigmentation and oxidative stress. In this context, we designed and synthesized pentapeptides that act as MC1R agonists. These peptides bound, with high potency, to MC1R and activated cAMP synthesis in CHO cells expressing human MC1R. Using one lead pentapeptide, we could show that this activation of MC1R was specific as testing the activation of other G-protein coupled receptors, including the MC-receptor family, was negative. In vitro efficacy on mouse melanoma cells showed similar potency as for the synthetic MC1R agonist alpha-melanocyte stimulating hormone (NDP-alpha-MSH). Moreover, we could reproduce this activity in human skin tissue culture. The lead pentapeptide was able to induce ex-vivo protein expression of key melanogenesis markers melanocyte inducing transcription factor (MITF), tyrosinase (TYR), and tyrosinase-related protein 1 (TYRP-1). Concerning oxidative stress response, we found that the pentapeptide enhanced the activation of Nrf2 after UVA-irradiation. Our results make this pentapeptide an ideal candidate as a skin pigmentation enhancer that mimics alpha-MSH and may also have anti-photoaging effects on the skin.

Whitening effects of cosmetic formulation in the vascular component of skin pigmentation.

Melanin plays an important role in protecting the skin against the harmful effects of solar radiation, but its abnormal accumulation may become an aesthetic problem, such as melasma and age spots. The aim of this study was to evaluate the antiangiogenic and whitening effects of a depigmentation formulation (BLTX) using an in vitro model of human cell and skin culture. Human fibroblasts, keratinocytes or melanocytes were treated with BLTX and subjected to oxidative stress by UV radiation or inflammatory stress with IL-1α for quantification of melanin, tyrosinase, endothelin-1, PAR-2, VEGF and iNOS. Fragments of human skin, from elective plastic surgery, were treated with BLTX and subjected to histological evaluation with hematoxylin/eosin associated with Fontana-Masson technique for melanin view. A parametric method, the one-way analysis of variance (ANOVA) followed by the Bonferroni test, was used to compare data among all groups. The results demonstrated that BLTX promotes a reduction in VEGF and iNOS protein synthesis in cultured dermal fibroblasts, indicating an antiangiogenic property. In relation to whitening effect, BLTX was able to reduce the production of melanin in both systems, melanocytes and human skin cultures. The depigmenting action was also revealed by decreasing the levels of endothelin-1, PAR-2 and activity of tyrosinase, when compared to cultures exposed to UV radiation. The results allow us to infer that BLTX presents an antiangiogenic effect indicating a role in the vascular component of melasma. Furthermore, the whitening property observed reinforces its use in the prevention and treatment of melasma.

A Survey on Awareness of Sun Exposure Among Farmers, Construction Workers, and Traffic Policemen in Erbil

Incidence rates of skin cancers, that is,nonmelanoma and melanoma, are increasing in many countries. Solar ultraviolet radiation (UVR) is widely accepted to be the main causal factor of these problems. Several people are occupationally exposed to solar UVR, including farmers, construction workers, and some public service workers. They are prone to skin cancer due to long-term exposure to UVR. Thus, an understanding of sun risks and sun protection tools is vital for them. The purpose of this study is to obtain a better understanding of how a subpopulation, that is, traffic policemen, construction workers, and other individuals, understands the sun risks and the benefits of sun protection and how they apply this knowledge. A total of 200 participants (86% male and 14 % female) were surveyed in the study. The survey data that were collected focused on knowledge of sun exposure, sun risk, and sun protection behavior. Differences in the answers to the survey questions were compared. Most of the individuals who were exposed to solar UVR for more than 6 h were traffic policemen and construction workers. In addition, most of these individuals did not experience sunburns. However,44% of the participants experienced skin redness and sunburn and 14% experienced more than five sunburns. Results showed that 30% of the participants had no knowledge of the harmful effects of solar radiation. Moreover, 72% of the participants did not apply sunscreen protection and 92% did not use an umbrella or shade. Meanwhile, 87% of the participants used shirts with sleeves as protection and 81% used a hat. Disparities in knowledge of the perceived risk of skin cancer from sun exposure and of the sun-protective behavior among construction workers, traffic policemen, and public service workers exist. In addition, effective prevention programs for outdoor workers are essential. Traffic policemen and construction workers should be educated on the effects of sun exposure and sun protection

Melanogenic effect of purified mushroom tyrosinase on B16F10 Melanocytes: A Phase Contrast and Immunofluorescence Microscopic Study

Cutaneous melanin pigment plays a critical role in camouflage, mimicry, social communication, and protection against harmful effects of solar radiation. It has been proven that tyrosinase plays a pivotal role in melanocytes dendrite formation; however, the molecular mechanism underlying this process has not been fully elucidated. The morphological changes were observed under a phase contrast microscope. These changes were evident, with globular cell bodies and increased numbers of tree branch-like dendrites. The present work aimed to study the morphoanatomic effects of purified tyrosinase to determine its skin-darkening potential using B16F10 melanocyte, which has not been done to date. Phase contrast and immunofluorescence microscopic analysis of B16F10 melanocytes has been done after treatment with various concentrations of purified tyrosinase along with standard tyrosinase (Sigma) in order to explore the mechanism of action of purified tyrosinase induced skin darkening. The phase contrast microscopic results showed that the number of melanocytes with melanin-loaded dendrites has increased significantly in purified tyrosinase treated cells in a dose dependent manner leading to skin darkening. In addition, immunofluorescence microscopic analysis revealed purified tyrosinase increase cellular tyrosinase expression in doze dependent manner due to tyrosinase absorption in B16F10 melanocyte. Present findings proved that purified tyrosinase possesses a skin darkening potential and could be used as a safe melanogenic agent for the treatment of hypopigmentation disorders or vitiligo.

Novel dyed ethylene-norbornene composites with enhanced aging resistance

The current research investigated the effects of anthraquinone solvent dyes and commercial stabilizers on the aging resistance properties of ethylene-norbornene (EN) composites subjected the aging in the full solar-spectrum for various time periods. During irradiation, the mechanical properties were measured by low and high degrees of deformation using dynamic mechanical analysis (DMA) and tensile tests until break, respectively. Changes in the color and surface defects in the investigated composites were evaluated using spectrophotometry and scanning electron microscopy (SEM). An accelerated aging test revealed that the application of solvent dyes with anthraquinone chromophores significantly prolonged the lifetimes of the EN composites during aging. The best improvement in durability was found in the EN samples that contained dyes, such as Solvent Blue 97, Solvent Blue 104, Solvent Blue and Solvent Green 28. Moreover, the ability of solvent dyes to protect EN composites against harmful effects of solar radiation was found to be much greater comparing to those of the investigated, commonly used stabilizers.

The color of plant reproduction: macroecological trade-offs between biotic signaling and abiotic tolerance

Flowers and fruits are often vividly coloured. An obvious explanation for fruit and flower pigmentation is that it serves to attract animal mutualists. However, decades of research has produced surprising little support for this hypothesis. Exciting new research into geographic variation in flower colours suggests an alternative explanation - flower pigments protect gametes against the damaging effects of solar radiation. Here, I present several new analyses suggesting that a similar explanation might apply to Rubus spectabilis, a much studied but poorly understood bird-dispersed fruit species. These and other recent results provide a new perspective on the colour of plant reproduction. In addition to signalling to animals, fruit and flower colours might often play vital roles in protecting plants against the harmful effects of solar radiation.

Evaluation of the Level of Transmission of Solar Radiation by Eyeglasses (Spectacles) and its Effects on the Human Eye

Global atmospheric changes such as depletion of Ozone in the stratosphere and global warming contribute to the average increase of ultraviolet radiation on earth. Protective eyeglasses are normally recommended to safeguard the eyes from the harmful effects of solar radiation. In this paper, twenty (20) pairs of eyeglasses were selected based on systematic random sampling to determine the amount of optical radiation transmission and level of attenuation by eyeglasses, in the wavelength range of 200nm to 900nm using 6405 UV/VIS spectrophotometer. All the eyeglasses were found to transmit a substantial amount of ultraviolet radiation. The transmission of visible light depends on the lens colours. It was discovered that the eyeglasses do not provide complete protection from UV radiation. This shows that the glasses can still pose great danger to human eyes.

Produits de protection solaire : efficacité et risques

Solar protection products (SPP) containing chemical filters and/or mineral filters are extensively used today in photoprotection; however, concerns continue to be voiced about their efficacy and about their possible dangers. A rapid review of photoprotection strategies shows that SPP owe their photoprotective effect to the absence of other photoprotection methods having clearly established efficacy in healthy subjects; in addition, they exhibit real protective efficacy against the majority of harmful effects of solar radiation, provided they have been devised in keeping with the specifications clearly set out in the recommendations of the French Medicines Agency (Afssaps). Such efficacy is dependent on their correct usage, recently reiterated by Afssaps in its recommendations to end-users concerning the good use of solar products: application of adequate quantities of such products, selection of the appropriate photoprotection class based on phototype and conditions of exposure, and regular renewal of applications in the event of prolonged exposure and after bathing or profuse sweating. Solar filters have long been known to cause contact allergic dermatitis, irritative dermatitis and photosensitisation, and a particular risk has appeared with the use of octocrylene. However, debate has centred primarily on the risk of endocrine disturbance potentially induced by chemical filters, certain of which exhibit established transcutaneous penetration. The risk of mimicry of an effect of oestradiol has been raised on the basis of a series of studies, almost all of which were carried out by the same team, and which mainly concerned 4-methylbenzylidene-camphor (4-MBC) following oral absorption in the rat. The risk of this type of effect with SPPs under normal conditions of use seems fairly remote according to the current state of knowledge; in any event, within the context of the "National Fertility Action Plan", Afssaps has been formally requested to analyse the risk associated with cosmetic substances that are "reprotoxic" and/or affect endocrine function, as a result of which various filters are currently being reassessed for such risk. The greater alleged safety of mineral filters, based on the absence of introduction of risk of photosensitisation (as a result of which they are preferred for use in young children), no longer seems so clear since the introduction of titanium dioxide (TiO2) and zinc oxide (ZnO) in the form of nanoparticles. Afssaps drew up a risk assessment report concerning cutaneous penetration, genotoxicity and oncogenesis for TiO(2) and ZnO in nanoparticle form; further studies are needed before any general conclusions may be drawn. The European Scientific Committee on Consumer Safety (SCCS) is also carrying out an evaluation of the use of TiO(2) and of ZnO as UV filters. Finally, current data do not suggest that SPPs exert any harmful effects by inhibiting the beneficial effects of the sun, in particular, vitamin D synthesis.

Photon-harvesting efficiency and arbuscular mycorrhiza in amphibious plants

The amphibious plant species of intermittent aquatic habitats thrive both submerged and emerged. In order to outline the adaptive characters of these two life forms photochemical efficiency of photosystem 2, leaf contents of chlorophyll (Chl) a and b, carotenoids (Car), anthocyanins (Ant), and UV-B absorbing compounds (UV-B abs), and root aerenchyma and arbuscular mycorrhizal (AM) colonisation were studied in Glyceria fluitans, Gratiola officinalis, Ranunculus lingua, Teucrium scordium, Sium latifolium, Sparganium emersum, and Veronica anagallis-aquatica. Water level fluctuations did not exert a severe effect on photon harvesting efficiency. Submerged specimens had higher contents of Car and Ant whereas higher contents of UV-B abs were found in emerged specimens indicating efficient protection against the harmful effects of solar radiation. Roots of all species studied had extensive aerenchyma and were colonised by AM fungi, which were significantly more abundant in emerged specimens. This is the first report on AM symbiosis in S. latifolium and S. emersum.