Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Sunlight”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56Linked to original sources
PubMed2006

The efficacy of vitamin E against oxidative damage and autoantibody production in systemic lupus erythematosus: a preliminary study.

The hypothesis that reactive oxygen species (ROS) modification of DNA is involved in the development of autoantibodies in systemic lupus erythematosus (SLE) is supported by the enhanced reactivity of anti-DNA antibodies to ROS-denatured DNA. We studied the efficacy of vitamin E against both oxidative DNA damage and autoantibody production in SLE. Urinary 8-hydroxydeoxyguanosine (8-OHdG), an indicator of oxidative DNA damage, and the anti-double-stranded DNA (anti-ds DNA) antibody, a predictor of disease activity, were assayed twice, first during the season with the most intense sunlight and then later in the year. Twelve women among 36 outpatients received vitamin E (150 to 300 mg/day) together with prednisolone (PSL). No significant age or daily dose of PSL differences were evident between patient groups. Urinary 8-OHdG in the PSL with vitamin E group (15.0 +/- 10.2 ng/mg during the period of intense sunlight and 11.7 +/- 8.7 ng/mg during the remainder of the year) did not differ significantly from that in the PSL without vitamin E group (20.0 +/- 23.2 and 11.0 +/- 5.9 ng/mg, at these respective times), but the anti-ds DNA antibody titer in the PSL with vitamin E group (17.9 +/- 20.3 IU/l during the period of intense sunlight and 16.3 +/- 19.4 IU/l during the remainder of the year) was significantly lower than that in the PSL without vitamin E group for both sunlight-defined periods (66.3 +/- 76.8 and 55.8 +/- 59.0 IU/l, at these respective times; P < 0.05). The present study suggests that vitamin E can suppress autoantibody production via a mechanism independent of antioxidant activity.

Adult↗
PubMed1991

Stability studies on the cyanobacterial nicotinic alkaloid anatoxin-A.

Anatoxin-a (ANTX-a) is a potent nicotinic cholinergic bicyclic secondary amine produced by some toxigenic strains of Anabaena spp. cyanobacteria (LD50 = 0.20-0.25 mg/kg i.p., mouse). Studies were undertaken to examine the effects of sunlight, pH, oxygen, and copper and iron, known catalysts of nitrogen oxidation, on the stability of ANTX-a. Photolysis of this extremely potent toxin was demonstrated under conditions resembling those which occur naturally. First-order decay kinetics of ANTX-a in sunlight was both pH and light intensity dependent. In the solutions examined, which represented expected biological conditions, the half-life of ANTX-a was on the order of 1-2 hr. This compares to half-lives on the order of several days in the absence of sunlight, even in the presence of metal ions. Mouse bioassays indicate that the breakdown products of ANTX-a, by both mechanisms, are inactive. Sunlight photolysis is concluded to be a possible important detoxification route of ANTX-a.

Animals↗
PubMed1990

Geographic variation in breast cancer mortality in the United States: a hypothesis involving exposure to solar radiation.

Epidemiologic and laboratory evidence suggests that vitamin D may play a role in reducing breast cancer risk. Lack of exposure to ultraviolet sunlight can increase the prevalence of vitamin D deficiency. This deficiency may place some populations at higher risk for breast cancer. The association between total average annual sunlight energy striking the ground and age-adjusted breast cancer mortality rates in 87 regions of the United States was evaluated. Annual age-adjusted mortality rates for breast cancer varied over a 1.8-fold range, from 17-19 per 100,000 in the South and Southwest United States to 33 per 100,000 in the Northeast; the overall U.S. rate was 27.3 per 100,000. Risk of fatal breast cancer in the major urban areas of the United States was inversely proportional to intensity of local sunlight (r = -0.80, P = 0.0001); multiple regression with stratospheric ozone measurements, r = -0.82, P = 0.0001). Vitamin D from sunlight exposure may be associated with low risk for fatal breast cancer, and differences in ultraviolet light reaching the United States population may account for the striking regional differences in breast cancer mortality. The ecological nature of this study is emphasized, and the possibility that an indirect association with dietary and socioeconomic factors could explain these findings is discussed.

Age Factors↗
PubMed2001

Photo-oxidation of biodegraded crude oil and toxicity of the photo-oxidized products.

We investigated the physicochemical changes resulting from irradiation by sunlight of biodegraded crude oil. An Arabian light crude oil sample was first subjected to microbial degradation. n-Alkanes and aromatic compounds such as naphthalenes, fluorenes, dibenzothiophenes and phenanthrenes possessing short, alkyl side chain(s) were almost completely degraded, while the contents of the saturated and aromatic fractions were reduced by 70% and 40%, respectively. This biodegraded oil was then suspended in seawater and exposed to sunlight irradiation for several weeks. The most remarkable change caused by the irradiation was a substantial decline in the aromatic fraction with a concomitant increase in the resin and asphaltene fractions. A 13C-nuclear magnetic resonance (NMR) spectroscopic analysis showed that the aromaticity of the biodegraded oil was significantly lower in the irradiated sample. A field desorption-mass spectrometric (FD-MS) analysis showed that sunlight irradiation reduced the average molecular weight of the oil components and formed oxygenated compounds. Consistent with this observation is that the oxygen content in the oil increased as the irradiation was prolonged. The bioavailability of the biodegraded oil was increased by the photo-oxidation: the growth of seawater microbes was minimal when the non-irradiated biodegraded oil was used as the source of carbon and energy; however, growth was significant when irradiated biodegraded oil was used. The concentration of dissolved organic carbon (DOC) increased linearly during the sunlight irradiation of the biodegraded oil, and this increase was matched by an increase in ultraviolet-absorptive materials in the seawater. The photochemically formed, water-soluble fraction (WSF) showed acute toxicity against the halophilic crustacean, Artemia.

Animals↗
PubMed1983

Reusable ultraviolet monitors: design, characteristics, and efficacy.

Reusable ultraviolet dosimetry badges have been developed that provide a visual indication of daily cumulative ultraviolet (UV) exposure. These two-sided, tapelike devices measure UV radiation emitted by sunlight or an artificial UV light source exposure by means of a photochromic aziridine color change reaction that is UV-integrating but optically reversible. UV radiation falling on the exposure side of the badge generates a color change that can be seen from the opposite or readout side. End points are indicated by a visual match of the photochromic with a surrounding reference. This paper describes the construction, component characteristics, and clinical testing of two versions of a new photochromic dosimeter that selectively responds to either UVB (280-320 nm) radiation or UVA (320-400 nm) radiation of the solar spectrum. One version of this monitor, sensitive only to the mid-range UVB, has a peak sensitivity to 300 nm and has four end point markers revealing color changes corresponding to 0.4, 0.8, 2.2, and 6.5 times the minimal erythema dose of an average Caucasian. A second version, sensitive only to UVA, has a peak sensitivity at 355 nm and can monitor exposures ranging from 0.8 to 10 joules/cm2. Outdoor efficacy testing has shown that the UVB monitor is an effective predictor of UV dose-related 24-hour erythema response induced by sunlight. Following a measurement, these monitors can be rezeroed by exposing the readout side to sunlight for a few minutes. They can be reused for eight to ten times. The limitation of the sunlight-calibrated UVB monitor tag is its failure to predict erythema response produced by artificial UVB sources such as FS40 sunlamps.

Calibration↗
PubMed1997

Human protoporphyria: reduced cutaneous photosensitivity and lower erythrocyte porphyrin levels during pregnancy.

BACKGROUND: Women with erythropoietic protoporphyria (EPP) have reported increased sunlight tolerance during pregnancy. Review of clinical information in an existing database for an EPP population study found five women who had six pregnancies while enrolled. All had experienced attenuated photosensitivity during gestation. OBJECTIVE: Our purpose was to gain insight into whether altered porphyrin metabolism during pregnancy might explain this phenomenon. METHODS: Erythrocyte protoporphyrin levels obtained for these women during six periods of gestation were compared with data accumulated over the course of several years during nongestational periods. RESULTS: Erythrocyte porphyrin levels were lower during pregnancy. The differences of the means for values obtained during nongestational periods versus values obtained during pregnancy for each woman were found to reach or approach significance (p < 0.05) by a paired t test when analyzed without regard for seasonality (p = 0.042) or when adjusted for possible seasonal effects of sunlight on erythrocyte porphyrin levels by separation into data sets for low sunlight months (October-April) (p = 0.039) or high sunlight months (May-September) (p = 0.057). CONCLUSION: These observations suggest that a beneficial physiologic effect of pregnancy in patients with EPP may be a lower circulating erythrocyte protoporphyrin burden that leads to reduced photosensitivity.

Adult↗
PubMed1999

Illumination of human keratinocytes in the presence of the sunscreen ingredient Padimate-O and through an SPF-15 sunscreen reduces direct photodamage to DNA but increases strand breaks.

On illumination with simulated sunlight, the UVB-absorbing sunscreen chemical 2-ethylhexyl-4-dimethylaminobenzoate (Padimate-O) generates excited species which inflict non-ligatable strand breaks on DNA in vitro and it also becomes mutagenic to yeast in vivo. Padimate-O is known to penetrate human skin but its effects on human cells are not clear. Here, we first simulate the sunlight which penetrates human skin and use it to illuminate human keratinocytes. The DNA damage observed in terms of UV-endonuclease-sensitive sites (ESS) and direct strand breaks per kilobase (kb) of DNA per joule per square metre agrees well with that predicted from action spectra based on monochromatic light. Using plasmid DNA in vitro, we find a very similar pattern of results. Next, we simulate the spectrum that results when the incident light is first attenuated by a film of sunscreen (SPF-15; 2 mg/cm(2)) containing benzophenone-3 (a UVA absorber), octyl methoxycinnamate (a UVB absorber), and Padimate-O. If the sunscreen is not in contact with keratinocytes it reduces direct DNA damage from sunlight (ESS). However, any Padimate-O in contact with the cells substantially increases indirect damage (strand breaks) even though the film of sunscreen reduces direct photodamage. We estimate that applying an SPF-15 sunscreen which contains Padimate-O to human skin followed by exposure to only 5 minimum erythemal doses (MED) of sunlight could, while suppressing the formation of ESS, increase strand breaks in cells under the epidermis by at least 75-fold compared to exposure to 1 MED in the absence of sunscreen.

4-Aminobenzoic Acid↗
PubMed2003

Bipyrimidine photoproducts rather than oxidative lesions are the main type of DNA damage involved in the genotoxic effect of solar UVA radiation.

Exposure to solar UV radiation gives rise to mutations that may lead to skin cancer. UVA (320-340 nm) constitutes the large majority of solar UV radiation but is less effective than UVB (290-320 nm) at damaging DNA. Although UVA has been implicated in photocarcinogenesis, its contribution to sunlight mutagenesis has not been elucidated, and DNA damage produced by UVA remains poorly characterized. We employed HPLC-MS/MS and alkaline agarose gel electrophoresis in conjunction with the use of specific DNA repair proteins to determine the distribution of the various classes and types of DNA lesions, including bipyrimidine photoproducts, in Chinese hamster ovary cells exposed to pure UVA radiation, as well as UVB and simulated sunlight (lambda > 295 nm) for comparison. At UVA doses compatible with human exposure, oxidative DNA lesions are not the major type of damage induced by UVA. Indeed, single-strand breaks, oxidized pyrimidines, oxidized purines (essentially 8-oxo-7,8-dihydroguanine), and cyclobutane pyrimidine dimers (CPDs) are formed in a 1:1:3:10 ratio. In addition, we demonstrate that, in contrast to UVB and sunlight, UVA generates CPDs with a large predominance of TT CPDs, which strongly suggests that they are formed via a photosensitized triplet energy transfer. Moreover, UVA induces neither (6-4) photoproducts nor their Dewar isomers via direct absorption. We also show that UVA photons contained in sunlight, rather than UVB, are implicated in the photoisomerization of (6-4) photoproducts, a quickly repaired damage, into poorly repaired and highly mutagenic Dewar photoproducts. Altogether, our data shed new light on the deleterious effect of UVA.

Animals↗
PubMed2006

Photodecomposition of methylmercury in an Arctic Alaskan lake.

Sunlight-induced decomposition of monomethylmercury (MMHg) reduces its availability for accumulation in aquatic food webs. We examined MMHg degradation in epilimnetic waters of Toolik Lake (68 degrees 38' N, 149 degrees 36' W) in arctic Alaska, a region illuminated by sunlight almost continuously during the summer. MMHg decomposition in surface water of Toolik Lake is exclusively abiotic and mediated by sunlight; comparable rates of MMHg decomposition were observed in filter-sterilized and unfiltered surface waters incubated under in situ sunlight and temperature conditions, and no MMHg was degraded in unfiltered aliquots incubated in the dark. Rates of photodecomposition are first order with respect to both MMHg concentration and the intensity of photosynthetically active radiation (PAR), except at the lake surface where rates of photochemical degradation are enhanced relative to PAR intensity and may be attributed to an additional influence of ultraviolet light. The estimated annual loss of MMHg to photodecomposition in Toolik Lake, though limited to a 100-d ice-free season, accounts for about 80% of the MMHg mobilized annually from in situ sedimentary production, the primary source in Toolik Lake. These results suggest that greater light attenuation in lacustrine surface waters, a potential result of increased loadings of dissolved organic matter due to continued warming in the Arctic, may result in less photodecomposition and subsequently greater availability of MMHg for bioaccumulation.

Alaska↗
PubMed2003

Photodecomposition of an acaricide, fenazaquin, in aqueous alcoholic solution.

Fenazaquin (I) is a new acaricide of the quinazoline class. The photodecomposition of I was studied in aqueous methanolic and 2-propanolic solution under UV light (30 h) and sunlight (70 h) separately. The photolytic half-lives in aqueous methanolic solution were found to be 17.1 h (UV) and 38.1 h (sunlight), whereas these were 12.9 h (UV) and 29.2 h (sunlight) for aqueous 2-propanolic solution; all followed a first-order reaction kinetics. Six photoproducts were obtained: beta-phenyl (p-tert-butyl) ethyl alcohol (II), 4-hydroxyquinazoline (III), p-tert-butyl vinyl benzene (IV), 2,4-dihydroxyquinazoline (V), phenyl (p-tert-butyl) acetic acid (VI), and 2-methyl-2-[4'-(2' '-hydroxyethyl)phenyl]propanoic acid (VII). Compounds VI and VII could be isolated only from aqueous 2-propanolic solution under sunlight irradiation. The major degradation products are formed as a result of cleavage of the ether bridge linking the quinazoline and phenyl ring systems of the molecule, oxidation of the tert-butyl substituent, and oxidation of the heterocyclic portion of the quinazoline ring. A probable mechanism of formation of the photoproducts is also suggested.

2-Propanol↗
PubMed2000

Distribution and repair of bipyrimidine photoproducts in solar UV-irradiated mammalian cells. Possible role of Dewar photoproducts in solar mutagenesis.

In order to better understand the relative contribution of the different UV components of sunlight to solar mutagenesis, the distribution of the bipyrimidine photolesions, cyclobutane pyrimidine dimers (CPD), (6-4) photoproducts ((6-4)PP), and their Dewar valence photoisomers (DewarPP) was examined in Chinese hamster ovary cells irradiated with UVC, UVB, or UVA radiation or simulated sunlight. The absolute amount of each type of photoproduct was measured by using a calibrated and sensitive immuno-dot-blot assay. As already established for UVC and UVB, we report the production of CPD by UVA radiation, at a yield in accordance with the DNA absorption spectrum. At biologically relevant doses, DewarPP were more efficiently produced by simulated solar light than by UVB (ratios of DewarPP to (6-4)PP of 1:3 and 1:8, respectively), but were detected neither after UVA nor after UVC radiation. The comparative rates of formation for CPD, (6-4)PP and DewarPP are 1:0.25 for UVC, 1:0. 12:0.014 for UVB, and 1:0.18:0.06 for simulated sunlight. The repair rates of these photoproducts were also studied in nucleotide excision repair-proficient cells irradiated with UVB, UVA radiation, or simulated sunlight. Interestingly, DewarPP were eliminated slowly, inefficiently, and at the same rate as CPD. In contrast, removal of (6-4)PP photoproducts was rapid and completed 24 h after exposure. Altogether, our results indicate that, in addition to CPD and (6-4)PP, DewarPP may play a role in solar cytotoxicity and mutagenesis.

Animals↗
PubMed1990

The use and interpretation of assays for vitamin D and its metabolites.

Vitamin D is essential for the maintenance of calcium and bone metabolism in humans. The recommended daily allowance (RDA) for vitamin D in the United States of 200 IU (5.0 micrograms) is reasonable for adults who receive some exposure to sunlight; however, in the absence of any exposure to sunlight, this recommendation may be 2 to 3 times lower than that actually required to satisfy the body's needs. Vitamin D was first measured by bioassays. However, bioassays became obsolete in light of the revelation that vitamin D must be activated first in the liver to 25-hydroxyvitamin D (25-OH-D) and then in the kidney to 1,25-dihydroxyvitamin D [1,25(OH)2D] before becoming biologically functional. Current assays measure circulating concentrations of vitamin D, 25-OH-D or 1,25(OH)2D. The serum vitamin D concentration is of value for determining the role of sunlight in producing vitamin D in skin and as a provocative test to determine the absorption of vitamin D in patients with malabsorption syndromes. The serum concentration of 25-OH-D is most valuable for determining the overall vitamin D status of an individual, since it is an average of dietary and sunlight-induced vitamin D. The measurement of the serum 1,25(OH)2D concentrations has been most useful in evaluating disorders in calcium and bone metabolism related to acquired and inborn errors in the conversion of 25-OH-D to 1,25(OH)2D.

25-Hydroxyvitamin D 2↗
PubMed2005

Refugial forests of the southern Appalachians: photosynthesis and survival in current-year Abies fraseri seedlings.

Fraser fir (Abies fraseri (Pursh) Poiret) is an endemic, high-elevation conifer confined to six relict mountaintop communities in the southern Appalachian Mountains, USA. High adult mortality has occurred over the past 50 years, possibly the result of an introduced insect (Adelges piceae Ratzeburg), air pollution, or both. Knowledge of the mechanisms of and limitations to seedling establishment may allow reestablisment and perpetuation of this unique community type, notwithstanding global climate change. We monitored seedling emergence and mortality in relation to photosynthetic performance and water relations in microsites differing in canopy openness (sunlight exposure) over the summer of 2004. Abundance of cotyledonous seedlings in early summer was 2.3 times greater (849 versus 366 seedlings m(-2)) in microsites with lower sky exposure (greater canopy closure) than in microsites with greater sky exposure (greater canopy openness). In contrast, late-season abundance and survival were greater in areas beneath more open canopies than in areas beneath less open canopies (3.3 times and 11.7 times greater, respectively). However, newly emerged seedling survival in a completely open site (no overhead canopy) was zero, despite an initial density of 124 seedlings m(-2). Seedling water status was similar in open- and closed-canopy sites (-0.52 and -0.74 MPa, respectively). Photosynthetic carbon gain was higher in newly emerged seedlings at open canopy than at closed canopy sites, especially during early morning. Based on photosynthetic light response curves and measured sunlight regimes, seedlings in open canopy sites were estimated to assimilate 3.3-4.5 times more carbon than seedlings at closed sites. Reductions in carbon gain of closed-site seedlings, primarily a result of limited sunlight, corresponded to substantial increases in seedling mortality (98 versus 79% in open canopy sites). Thus, sunlight exposure, which reflects overstory canopy structure, appears to be an important factor influencing newly emerged seedling survival and distribution.

Abies↗
PubMed2006

Functional traits and plasticity in response to light in seedlings of four Iberian forest tree species.

We investigated the differential roles of physiological and morphological features on seedling survivorship along an experimental irradiance gradient in four dominant species of cool temperate-Mediterranean forests (Quercus robur L., Quercus pyrenaica Willd., Pinus sylvestris L. and Pinus pinaster Ait.). The lowest photochemical efficiency (F(v)/F(m) in dark-adapted leaves) was reached in deep shade (1% of full sunlight) in all species except Q. robur, which had the lowest photochemical efficiency in both deep shade and 100% of full sunlight. Species differed significantly in their survival in 1% of full sunlight but exhibited similar survivorship in 6, 20 and 100% of full sunlight. Shade-tolerant oaks had lower leaf area ratios, shoot to root ratios, foliage allocation ratios and higher rates of allocation to structural biomass (stem plus thick roots) than shade-intolerant pines. Overall phenotypic plasticity for each species, estimated as the difference between the minimum and the maximum mean values of the ecophysiological variables studied at the various irradiances divided by the maximum mean value of those variables, was inversely correlated with shade tolerance. Observed morphology, allocation and plasticity conformed to a conservative resource-use strategy, although observed differences in specific leaf area, which was higher in shade-tolerant species, supported a carbon gain maximization strategy. Lack of a congruent suite of traits underlying shade tolerance in the studied species provides evidence of adaptation to multiple selective forces. Although the study was based on only four species, the importance of ecophysiological variables as determinants of interspecific differences in survival in limiting light was demonstrated.

Light↗
PubMed1992

The comparison of sun protection factor values with different light sources.

Sun protection factors (SPFs) were evaluated with three light sources (sunlight, a xenon arc solar simulator, and fluorescent lamps) in indoor and outdoor studies. Two types of light, UV-A+B and UV+Visible, were obtained from the solar simulator. The untanned backs of twenty-four healthy male volunteers were used as test sites. A broad spectrum sunscreen containing SPF 6, according to the manufacturer, was used. The sunscreen tested was applied at 2 mg/cm2. The actual SPF values were 4.8 with sunlight, 6.0 with UV-A+B, 4.9 with UV+Visible, and 11.8 with fluorescent lamps. There were no significant differences between the SPF values with sunlight and those with the solar simulator; the SPF value for fluorescent lamps was significantly higher. The SPF with UV-A+B of the solar simulator was similar to that with sunlight; the use of this light served to reduce pain on tested subjects. Therefore, UV-A+B from the solar simulator seems to be the most appropriate artificial light source for evaluating sunscreens.

Adult↗
PubMed1994

Age-related changes in the elastic properties and thickness of human facial skin.

Using recently designed, commercially available, non-invasive instruments, we measured the thickness and elasticity of the skin of the face and ventral forearm in 170 women, and evaluated the effects of age and exposure to sunlight. Skin thickness decreased with age in ventral forearm skin, which has limited exposure to sunlight, but increased significantly in the skin of the forehead, corners of the eyes, and cheeks, which are markedly exposed to sunlight. Skin elasticity (Ur/Uf) decreased with age on both the face and forearm. The ratio of viscosity element to elasticity element (Uv/Ue) increased with age at all sites. However, delayed distension (Uv), immediate retraction (Ur), final distension (Uf), and immediate distention (Ue), as individual elements, decreased on the face and increased on the forearm with age. This tendency was more marked after correction for skin thickness. These results suggested the specificity of skin thickness and elasticity in the facial skin. Analysis using a four-element model showed no changes in the elasticity coefficient of Maxwell element on the forearm, but an increase on the face. This indicates quantitative or qualitative changes in elastic fibres in facial skin. Thus, sunlight appears to have a considerable effect on the thickness and physical properties of facial skin.

Adolescent↗
PubMed1997

Epidemiology of non-melanoma skin cancer and solar keratoses in Australia: a tale of self-immolation in Elysian fields.

Non-melanoma skin cancers (NMSC) are the commonest cancers in Australia. Their incidence rate is more than three times the rate of all other cancers combined. The incidence rate continues to rise to a stage where they now affect at least 1% of the population annually, necessitating treatment of more than 150,000 people per year. Exposure to sunlight in susceptible people appears to be the major environmental carcinogen in causation of these tumours. The exact nature of sunlight exposure necessary to induce them is still not entirely clear. Childhood exposure to sunlight stands out as being the major contributor to the development of all the common skin cancers. Solar keratoses are risk factors for NMSC and are precursors of squamous cell carcinoma. They appear to be more sensitive measures of carcinogenic sunlight exposure than frank invasive tumours. They are labile, and fluctuate in appearance clinically over time. Regular use of sunscreen can prevent new solar keratoses and increase clinical remission in existing ones. This is early evidence of the value of regular and adequate photoprotection in the long-term reduction of NMSC in Australia.

Adult↗
PubMed1999

Correlation of skin phototype with facial wrinkle formation.

Facial wrinkle formation is a representative sign of photoaging. Skin can be divided into different skin phototypes (SPTs) depending on its sensitivity to solar radiation. We have determined the relationship between SPTs and deep and fine wrinkle scores on the faces of 230 Japanese subjects. This group was chosen because it is relatively easy to quantify acute and chronic sun damage in Japanese individuals. SPT in the Japanese subjects was classified into one of four groups, SPT-I to -IV according to Fitzpatrick's classification method. The subjects were further classified into indoor or outdoor workers. After photographing the outer canthus, deep and fine wrinkles were discriminated visually and scored from 1-11 and from 1-9, respectively. UV light was used as a photographic light source for clear depiction of the fine wrinkles. Higher scores were recorded for deep wrinkles in individuals with SPT-I, who are more sensitive to sunlight than those with SPT-III or IV, who are more tolerant to sunlight. However, the same tendency did not seem to be apparent for fine wrinkle scores. A high incidence of SPT-IV was seen in outdoor workers. Early detection of SPT-I in individuals who are sensitive to sunlight, may help to predict and prevent photoaging of deep wrinkles. Sensitivity to sunlight may play a part in determining an individual's choice of working environment.

Adult↗