Skin protection from solar ultraviolet radiation using natural compounds: a review

In the paper

“The authors substantiated this by reporting that trend estimates of ultraviolet irradiance showed no significant difference during study periods”

What the sources say

• ?Not checked — no full text of the sourcecites Chubarova et al. 2018 source
• Disputed

  Section 4.4 (page unavailable) reports statistically significant positive surface-UV trends in some regions and significant negative trends at ground-observation sites in the Northeast and Ohio River Valley. The Conclusion and discussion (page unavailable) also says estimated trends differ by sampling method. This contradicts the unqualified claim that trend estimates showed no significant difference. (LLM, conf=0.86)

  Checked by a reasoning model — may be wrong.

  cites Zhang et al. 2019 sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites Aun et al. 2019 source

In the paper

“The development of carcinoma depends on the UV-A and UV-B absorption by the superficial skin layers and is mainly responsible for oxidative damage to cellular DNA, proteins and lipids, via photosensitized reactions, which can lead to mutations in key cancer genes”

What the sources say

• Partly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  cites D'Orazio et al. 2013 sourceExperimental — accuracy not yet measured

In the paper

“Photocarcinogenesis is the result of a series of simultaneous and sequential biochemical reactions that eventually result in skin cancer”

What the sources say

• Supported

  The Mechanisms of Photocarcinogenesis section describes a systematic sequence in which molecular and biochemical changes accumulate in keratinocytes, leading to basal and squamous cell carcinomas. Its initiation, promotion, and progression stages support the claim's description of a multistep process leading to skin cancer. (LLM, conf=0.91)

  cites Subhadarshani et al. 2020 source

In the paper

“Physical ultraviolet filters, such as sunglasses and sun clothing, and chemical ultraviolet filters, such as sunscreen lotions, are both useful, but they do not offer comprehensive protection”

What the sources say

• Supported

  The Conclusions recommend sunscreen, protective clothing, hats and UV-protective sunglasses together. They also advise repeated sunscreen application and coverage of often-missed areas, supporting the point that these measures are useful but do not individually provide comprehensive protection. No page number is available in our copy. (LLM, conf=0.86)

  cites D'Orazio et al. 2013 source
• Partly supported

  The Introduction (page unavailable) describes chemical and physical UV filters as sunscreen ingredients used to minimize UV-related harm, and notes that melanoma prevalence has risen despite increasing sunscreen use. It does not identify sunglasses or sun clothing as physical UV filters or assess whether those items offer comprehensive protection. Instead, it names zinc oxide and titanium dioxide as physical filters. (LLM, conf=0.84)

  cites Ruszkiewicz et al. 2017 sourceExperimental — accuracy not yet measured
• Supported

  The Photoprotective measures section describes clothing and sunglasses as effective physical barriers and says sunscreen minimizes UV damage but should not be used to justify longer sun exposure. The Chemical or organic sunscreens section describes UV protection from sunscreen ingredients, while the paper recommends combining these measures with shade and reduced exposure. Page numbers are unavailable in our copy. (LLM, conf=0.88)

  cites Garnacho Saucedo et al. 2020 source

In the paper

“Sunscreens can induce side effects such as irritation, allergy and phototoxic reactions, affect the synthesis of vitamin D, generate reactive oxygen species and act as photosensitizers (DiNardo and Downs 2018;Ngoc et al. 2019;Neale et al. 2019;Passeron et al. 2019;Narla and Lim 2020;Suh et al. 2020).”

What the sources say

• ?Not checked — no full text of the sourcecites DiNardo and Downs 2018 source
• Partly supported

  Section 2.5 reports contact sensitivity, photoallergic dermatitis, and a possible reduction in vitamin D production from sunscreen use, while noting conflicting findings on vitamin D. Section 2.2 says sunscreen nanoparticles can produce reactive oxygen species. The review does not establish phototoxic reactions or that sunscreens act as photosensitizers; the latter term appears in a reference title. (LLM, conf=0.86)

  cites Ngoc et al. 2019 sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites Neale et al. 2019 source

In the paper

“For example, sun protection factors 15, 30, 45 and 50 block/absorb the UV-B light 93.3%, 96.7%, 97.8% and 98.0%, respectively (Wilson et al. 2012).”

What the sources say

• ?Could not verify

  The Introduction discusses surface UV radiation and its health impacts, but does not discuss sunscreen. Searches for SPF, sunscreen, and the four stated UV-B blocking percentages found no supporting passage in our copy. The citing sentence names Wilson et al. (2012), but our copy does not identify that work as the source of these figures. (LLM, conf=0.76)

  cites Wilson et al. 2012 sourceExperimental — accuracy not yet measured

In the paper

“Bernhard et al. (2020) reported that changes in ultraviolet radiation during the last twenty years have been generally minimal, resulting in less than 4% in a decade.”

What the sources say

• Supported

  Section 1.6 (p. 10) states that changes in UV radiation during the last 20 years have generally been small—less than approximately 4% per decade—with few exceptions. This supports the citing sentence’s paraphrase. (LLM, conf=0.94)

  cites Bernhard et al. 2020 source

In the paper

“Ultraviolet radiation has been shown to cause significant changes in the skin as well as modify immunological responses (Shen et al. 2016).”

What the sources say

• Partly supported

  The Results section (“Transcriptomic responses to different UVR conditions”; page unavailable) reports substantial UV-induced gene-expression changes in cultured human keratinocytes, including enrichment of inflammatory-response and leukocyte-activation pathways. This supports changes in skin cells and immune-related gene expression, but the Discussion cautions that cultured cells do not capture interactions among cell types in vivo; the paper does not directly establish a modified immunological response in skin. (LLM, conf=0.84)

  cites Shen et al. 2016 sourceExperimental — accuracy not yet measured

In the paper

“Indirect photolysis in an aquatic environment thereby generates toxins, like cyclodimers and benzoic acids, from the untreated effluents, with the consequence that aquatic life is greatly hampered.”

What the sources say

• Partly supported

  The “Pathways of UV filters from sunscreens to the environment” section (page not provided) says direct or indirect photolysis can form harmful by-products, including substituted benzoic acids and cyclodimers. It also says wastewater effluents can carry residual UV agents into marine ecosystems. It does not specifically say these by-products form from untreated effluents or establish that the by-products themselves greatly hamper aquatic life. (LLM, conf=0.84)

  cites Chatzigianni et al. 2022 sourceExperimental — accuracy not yet measured

In the paper

“According to current research, skin microorganisms have an impact on gene expression in the skin and are responsible for training and adjusting its immunological response (Belkaid and Segre 2014;Meisel et al. 2018).”

What the sources say

• ?Not checked — no full text of the sourcecites Belkaid and Segre 2014 source
• Supported

  The Discussion reports that microbial colonization changes gene expression in the skin and describes the microbiome as priming the cutaneous immune response. The Conclusions likewise state that the skin microbiome mediates immune-response processes at the transcriptional level. (LLM, conf=0.88)

  cites Meisel et al. 2018 source

In the paper

“Umar and Tasduq (2022) highlighted the positive impacts of ultraviolet radiation on human skin which ranges from the enhancement of melanogenesis that acts as natural sunscreen inherent in dark-skinned people, to ultraviolet radiation phototherapeutic treatment of inflamed cutaneous conditions.”

What the sources say

• Supported

  In “UV Induced Melanogenesis Acts as a Natural Sunscreen,” the paper says UV exposure promotes melanin synthesis and describes melanin’s photoprotective effect. In “UV Phototherapy in Treatment of Numerous Cutaneous Disorders,” it describes UV phototherapy for inflammatory skin conditions, including psoriasis and atopic dermatitis. The comparison of skin-cancer incidence in White and Black subjects also supports the reference to darker skin. (LLM, conf=0.94)

  cites Umar and Tasduq (2022) source

In the paper

“Abundant melanin pigmentation and thicker dermis layer might help to shroud wrinkles, but indirect DNA lesions and oxidative stress are catalyzed by the availability of more melanin pigments”

What the sources say

• Partly supported

  Section 2 says pheomelanin is phototoxic and promotes UV-induced damage, supporting a limited link between a type of melanin and skin damage. It also says eumelanin is photoprotective. The Introduction mentions wrinkles but does not say pigmentation or a thicker dermis conceals them; sections 3.1 and 3.2 do not establish that more melanin catalyzes oxidative stress or indirect DNA lesions. (LLM, conf=0.82)

  cites Lee 2021 sourceExperimental — accuracy not yet measured

In the paper

“Squamous cell carcinoma is the second most common type of non-melanoma skin cancer.It is responsible for roughly 20% of all skin cancer cases discovered”

What the sources say

• Partly supported

  The paper’s Abstract says basal cell carcinoma and squamous cell carcinoma are the two most common non-melanoma skin cancers, with basal cell carcinoma far more frequent. The Discussion reports that squamous cell carcinoma accounts for approximately 20% of cutaneous malignancies in lighter-skinned populations, particularly Caucasians; it does not establish that percentage for all skin cancer cases without that population qualifier. (LLM, conf=0.88)

  cites Prasad et al. 2014 sourceExperimental — accuracy not yet measured

In the paper

“Generally, there is abundant evidence that ultraviolet radiation is carcinogenic to humans, and it forms the major driver of other underlying medical conditions ranging from eye defects, sunburn, skin disorder and hair damage”

What the sources say

• Partly supported

  Section 2 (page unavailable) identifies melanoma and non-melanoma skin cancers among the best-known long-term effects of solar radiation and says effects on the skin and eyes are mostly attributed to UVA and UVB. It does not substantiate the full list in the claim: searches for sunburn and hair damage found no passage attributing those effects to UV radiation. (LLM, conf=0.86)

  cites Grandi & D'Ovidio 2020 sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites Kim & Giovannucci 2020 source
• Partly supported

  The 'UV from sun and sunbeds' section identifies UVB's carcinogenic potential, supporting the cancer-risk portion of the claim. But 'Sun and cutaneous malignant melanoma' says the causal role of sun exposure in melanoma is disputed, and the cited passages do not establish UV as a major driver of eye defects, skin disorders, or hair damage. Page numbers are unavailable in our copy. (LLM, conf=0.88)

  cites Moan et al. 2012 sourceExperimental — accuracy not yet measured

In the paper

“Ultraviolet radiation has been shown to alter the composition and activity of the microbiota, as well as modulate cellular response and immunological function”

What the sources say

• Partly supported

  The Introduction and Results (page unavailable) report that UV-B changes skin gene expression, cellular responses, and immune function, with effects that differ depending on whether a skin microbiome is present. They do not show that UV alters the composition or activity of the skin microbiota; the study compares mice with and without microbiomes rather than measuring UV-induced changes in the microbes. (LLM, conf=0.88)

  cites Patra et al. 2019 sourceExperimental — accuracy not yet measured

In the paper

“According to an in vitro study, UV-B irradiation increased the number of human keratinocyte (HaCaT) cells in the gap 2-mitosis phase of the cell cycle, but pretreatment with sanguinarine dramatically shifted cells toward the synthesis phase.”

What the sources say

• Partly supported

  The Discussion (page not supplied) says UVB caused G2–M arrest in HaCaT cells and sanguinarine pretreatment caused significant S-phase arrest at 15 mJ/cm² UVB. At 30 mJ/cm², however, pretreatment caused G2–M arrest instead, so the claimed shift toward S phase needs a low-dose qualifier. (LLM, conf=0.91)

  cites Reagan-Shaw et al. 2006 sourceExperimental — accuracy not yet measured

In the paper

“Porphyrins play a vital role in the function of hemoglobin, ultraviolet rays also directly affect cutaneous propionibacteria such as Propionibacterium acnes by reducing their porphyrin production (Wang et al. 2012).”

What the sources say

• Supported

  The Results section (“Porphyrin Production in P. acnes Serves as a Parameter of UV Radiation,” Figure 2) reports that porphyrin production in P. acnes fell as UV-B dose increased. The human facial bacteria results (Figure 4) also show a dose-dependent reduction after UV-B exposure. The cited evidence concerns UV-B specifically. (LLM, conf=0.93)

  cites Wang et al. 2012 source

In the paper

“This finding was based on the 16S rDNA sequencing and reveals a decrease in the family Lactobacillaceae and Pseudomonadaceae while the phylum Cyanobacteria increased following ultraviolet radiation exposure (Burns et al. 2019).”

What the sources say

• Supported

  The Methods (DNA isolation and microbiome analysis; page not provided) describe sequencing the V4 region of the 16S rDNA gene. The Results (UV exposure alters the skin microbiome; page not provided) report a general increase in Cyanobacteria and decreases in Lactobacillaceae and Pseudomonadaceae after UVA and UVB exposure, while noting some individual exceptions. (LLM, conf=0.94)

  cites Burns et al. 2019 source

In the paper

“This enzyme possesses intriguing features that may be useful in lowering oxidative damage caused by ultraviolet exposure (Souak et al. 2021).”

What the sources say

• Supported

  Section 4.2 identifies RoxP as an antioxidant enzyme and says it has properties that could be useful in reducing oxidative stress linked to UV exposure. The citing sentence preserves that tentative wording. (LLM, conf=0.95)

  cites Souak et al. 2021 source

In the paper

“Phytochemicals may operate in a variety of ways, including being capable of absorbing the ultraviolet and act as filters, stimulating the immune system, triggering gene suppression, stopping oxidative DNA damage, detoxifying carcinogens and initiating specific signaling pathways (Vanhaelewyn et al. 2020).”

What the sources say

• Partly supported

  The section on phenolics (page unavailable) says flavonoids absorb UV radiation, filter harmful UV-B rays, and act as antioxidants. It also describes antimicrobial effects and plant defense responses. It does not support the full list of mechanisms attributed to phytochemicals, particularly stimulation of the immune system, gene suppression, prevention of oxidative DNA damage, or detoxification of carcinogens; the DNA Damage section instead discusses separate DNA-repair mechanisms. (LLM, conf=0.88)

  cites Vanhaelewyn et al. 2020 sourceExperimental — accuracy not yet measured

In the paper

“Rabiei et al. showed that ultraviolet protection of workwear fabrics can be improved by coating titania nanoparticles (Rabiei et al. 2022).”

What the sources say

• Supported

  The Conclusion reports that TiO2-coated textiles had greater ultraviolet protection factor (UPF) values than uncoated textiles and explicitly concludes that coating workwear fabrics with TiO2 nanoparticles can improve their UV protection. (LLM, conf=0.95)

  cites Rabiei et al. 2022 source

In the paper

“Also, oral photoprotectants do not offer full skin protection, but they provide a boost to set photoprotection in motion in living organisms (Torres-Contreras et al. 2022).”

What the sources say

• Supported

  Section 3, “Plant-Derived Molecules as Skin Photoprotection Agents” (page not provided), says oral photoprotectors do not directly protect the skin but can boost or activate its photoprotective mechanisms. This supports the citing sentence’s distinction between incomplete protection and a boost to the body’s defenses. (LLM, conf=0.90)

  cites Torres-Contreras et al. 2022 source

In the paper

“About 52% of the reviewed articles, as shown in the Supplementary Material, addressed the impacts of ultraviolet radiation on biotic and abiotic environments, with major reports bordering on marine/aquatic life responses to the ultraviolet effect.”

In the paper

“Thirty-four of the articles reviewed for this work presented findings on the beneficial and adverse effects of ultraviolet radiation on human health.”

In the paper

“However, chronic exposure to solar ultraviolet radiation, especially UV-A and UV-B, generates oxidative stress and induces skin damage.”

What the sources say

• ?Not checked — no full text of the sourcecites Sardoiwala et al. 2018 source

In the paper

“Nevertheless, its limitation in cosmetics applications is an uneven distribution on the skin due to lumping; thus, the uncovered areas are exposed to sunlight, not resistant to water, and easily washed off by sweating and water contact giving the skin a comparatively whiter than normal shade.”

What the sources say

• ?Not checked — no full text of the sourcecites Saka and Chella 2021 source

In the paper

“For example, coal tar is used to treat psoriasis, which contains polycyclic aromatic hydrocarbons: It is applied topically to the skin followed by ultraviolet radiation exposure.This treatment has been implicated in the pathogenesis of acquiring skin cancer”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites Fu et al. 2012

In the paper

“Photochemical and cytological studies suggested that para-aminobenzoic acid interacts with DNA following ultraviolet radiation and might potentiate photocarcinogenesis.”

What the sources say

• ?Not checked — no full text of the sourcecites Shaw et al. 1992 source

In the paper

“These polycyclic aromatic hydrocarbons go through a series of photochemical processes that result in the production of reactive oxygen species and photoproducts, which can damage cell membranes and DNA, and cause cell death”

What the sources say

• ?Not checked — no full text of the sourcecites Mujtaba et al. 2018 source
• ?Not checked — no full text of the sourcecites Yadav and Banerjee 2018 source

In the paper

“The application of sunscreen before exposure to ultraviolet radiation, prevents sunburn, skin damage as well as skin cancer (Medeiros and Lim 2010;Mancebo et al. 2014).”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites Medeiros and Lim 2010
• ?Not checked — no full text of the sourcecites Mancebo et al. 2014 source

In the paper

“Occupational exposure to polycyclic aromatic hydrocarbons can induce breathing problems, chest pain and vexing coughing, as well as cancer”

What the sources say

• ?Not checked — no full text of the sourcecites Srivastav et al. 2018 source

In the paper

“According to studies, after ultraviolet radiation exposure, these ingredients become photosensitized and form toxic photoproducts, which causes genetic damage and apoptosis in skin cells”

What the sources say

• ?Not checked — no full text of the sourcecites Goyal et al. 2015 source
• ?Not checked — no full text of the sourcecites Yadav and Banerjee 2018 source

In the paper

“Sunburn is caused mostly by UV-B, which is a substantial risk factor for skin cancer, particularly melanoma.”

In the paper

“UV-A causes genetic damage to cells, photoaging and immunosuppression when it penetrates deep into the dermis of the skin.”

In the paper

“Generally, ultraviolet radiation in form of UV-A and UV-B penetrates beyond the stratospheric ozone layer and delivers both beneficial and adverse effects on human health, plants, air quality, biogeochemical systems, and aquatic and terrestrial ecosystems.”

In the paper

“As a result, physical and chemical measures of photoprotection are insufficient, and an alternative is necessary.”

In the paper

“According to a recent study, nabumetone, which is used as anti-inflammatory medicine, loses its function when exposed to UV-A and UV-B, and rises inflammatory markers”

What the sources say

• ?Not checked — no full text of the sourcecites Qureshi et al. 2021 source

In the paper

“It might be harmful to fetuses and children because it can be transmitted during suckling.”

In the paper

“Anti-inflammatory drugs such as ketoprofen, naproxen showed phototoxic products and induce dermatological complications like photoallergic responses”

What the sources say

• ?Not checked — no full text of the sourcecites Liu et al. 2007 source
• ?Not checked — no full text of the sourcecites Ray et al. 2013 source

In the paper

“Inadequate sunlight exposure induces the prevalence of cardio-metabolic diseases, resulting in low vitamin D synthesis in Africans and Asians residing in temperate regions”

What the sources say

• ?Not checked — no full text of the sourcecites Davis 2011 source

In the paper

“Although people with darker skin complexion experience less noticeable erythema symptoms manifest as redness of the skin or sunburn upon longer sunlight exposure, it is appropriate to say that carcinogenic threats and DNA damage can appear as malignant as those affecting people of lighter skin tones.”

In the paper

“It is most frequent in Caucasian populations and uncommon among Asians and African black races”

What the sources say

• ?Not checked — no full text of the sourcecites Chu et al. 2007 source

In the paper

“Photosensitized sunscreen agents lose their protection efficacy, trigger phototoxic reactions and induce skin cell damage”

What the sources say

• ?Not checked — no full text of the sourcecites Gonçalo 2011 source
• ?Not checked — no full text of the sourcecites Amar et al. 2015 source

In the paper

“With increasing overall lifetime exposure to sunlight/solar radiation, the risk of photocarcinogenesis in the head, neck, trunk and limbs rises.”

In the paper

“Voriconazole and itraconazole are antifungal drugs that have been linked to liver damage, phototoxicity and cutaneous squamous cell cancer.”

What the sources say

• ?Not checked — no full text of the sourcecites Mujtaba et al. 2018 source

In the paper

“UV-B, on the other hand, only penetrates the epidermis and damages cells.”

In the paper

“Nearly 80% of all occurrences of non-melanoma skin cancer are caused by basal cell carcinoma.”

In the paper

“Usually, these chemical filters penetrate the skin, reach the circulatory system and can have a systemic action on the body and filters undergo changes and degradation”

What the sources say

• ?Not checked — no full text of the sourcecites Saka and Chella 2021 source

In the paper

“It also observed that UV-B activation of chrysene enhances the intercellular oxidative stress and causes apoptosis by activating caspases-3 and phosphatidylserine translocation in skin cells.”

What the sources say

• ?Not checked — no full text of the sourcecites Srivastav et al. 2018 source

In the paper

“The abundance of eumelanin in dark skin offers superior defense against UV-induced damage, with eumelanin being considered more effective in its photoprotective properties than pheomelanin (Gloster and Neal 2006).”

What the sources say

• ?Not checked — no full text of the sourcecites Gloster and Neal 2006 source

In the paper

“However, photocarcinogenesis is dependent on a few factors, for example age, gender and the thickness of the skin.”

In the paper

“With the most common benefit known to be vitamin D synthesis”

In the paper

“After ultraviolet exposure, DNA damage, potent phospholipid activator formation factor and isomerization of inactive trans-to active cis-urocanic acid, are the primary key events in immunosuppression (Bernard et al. 2019).”

What the sources say

• ?Not checked — no full text of the sourcecites Bernard et al. 2019 source

In the paper

“Photosensitized methyl paraben and triclosan showed cytotoxicity, genotoxicity, arrest the cell cycle of skin cells and triggered apoptosis as well as plate sensitivity test showed a reduction in antibacterial activity”

What the sources say

• ?Not checked — no full text of the sourcecites Dubey et al. 2017 source

In the paper

“It has also been suggested that genistein could be used as a potent inhibitor for photocarcinogenesis (Moore et al. 2006).”

What the sources say

• ?Not checked — no full text of the sourcecites Moore et al. 2006 source

In the paper

“Some other studies reveal that cotton-based fabrics have excellent properties for ultraviolet protection (Kocić et al. 2019).”

What the sources say

• ?Not checked — no full text of the sourcecites Kocić et al. 2019 source

In the paper

“Grape seed proanthocyanidins belong to a class of phenolic compounds renowned for their potent antioxidant properties, safeguarding the body against premature aging, diseases and deterioration (Sharma et al. 2007).”

What the sources say

• ?Not checked — no full text of the sourcecites Sharma et al. 2007 source

In the paper

“A recent study showed that anthocyanins against UV-B induced oxidative damage in keratinocyte cells and the activation of Nrf 2 (nuclear factor E2-related factor 2) signaling.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites Li et al. 2019

In the paper

“All these findings should help researchers better understand how to treat ultraviolet-induced skin damage and other skin illnesses connected to microbiome changes or ultraviolet radiation exposure.”

In the paper

“Modification of gene expression, activation or inactivation of regulatory pathways, immunological and inflammatory processes, and induction of apoptosis are all examples of photooxidative reactions that disrupt the function of cellular responses.”

In the paper

“In textile manufacturing, polysorbate improved ultraviolet exposure protection and the esthetics of polyester fabric (Sk et al. 2022).”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites Sk et al. 2022

In the paper

“Natural agents and secondary plant extracts have been elaborately discussed and presented to offer future prospects as sustainable options for sunscreen technology.”

In the paper

“It has antimutagenic, anti-inflammatory and anticarcinogenic (Nandakumar et al. 2008) properties.”

What the sources say

• ?Not checked — no full text of the sourcecites Nandakumar et al. 2008 source

In the paper

“Piperine was also observed to lower ultraviolet radiation-mediated DNA damage, micronuclei creation and the sub-Gap 1 phase of the cell cycle, all of which helped to protect against photogenotoxicity.”

What the sources say

• ?Not checked — no full text of the sourcecites Verma et al. 2017 source

In the paper

“All these studies show that ultraviolet radiation has significant qualitative and quantitative effects on the skin microbiota, potentially affecting skin pathology where ultraviolet radiation is a factor.”