BACKGROUND: Solar furnaces are used worldwide to conduct experiments to demonstrate the feasibility of solar–chemical processes with the aid of concentrated sunlight, or to qualify high temperature-resistant components. In recent years, high-flux solar simulators (HFSSs) based on short-arc xenon lamps are more frequently used. The emitted spectrum is very similar to natural sunlight but with dangerous portions of ultraviolet light as well. Due to special benefits of solar simulators the increase of construction activity for HFSS can be observed worldwide. Hence, it is quite important to protect employees against serious injuries caused by ultraviolet radiation (UVR) in a range of 100 nm to 400 nm. METHODS: The UV measurements were made at the German Aerospace Center (DLR), Cologne and Paul-Scherrer-Institute (PSI), Switzerland, during normal operations of the HFSS, with a high-precision UV-A/B radiometer using different experiment setups at different power levels. Thus, the measurement results represent UV emissions which are typical when operating a HFSS. Therefore, the biological effects on people exposed to UVR was investigated systematically to identify the existing hazard potential. RESULTS: It should be noted that the permissible workplace exposure limits for UV emissions significantly exceeded after a few seconds. One critical value was strongly exceeded by a factor of 770. CONCLUSION: The prevention of emissions must first and foremost be carried out by structural measures. Furthermore, unambiguous protocols have to be defined and compliance must be monitored. For short-term activities in the hazard area, measures for the protection of eyes and skin must be taken.
Compliance ; Skin ; Sunlight ; Switzerland ; Ultraviolet Rays ; Xenon*

The color change of maxillofacial silicone has been attributed to certain environmental factors such as exposure to the UV component of natural sunlight, wetting and drying of the elastomer, and surface abrasion resulting from the application and removal of cosmetics. The purpose of this study was to evaluate the color change of maxillofacial silicone (Silastic MDX4-4210) according to type of pigment (cadmium yellow, titanium white, cosmetic red), and UV absorber application method after 200, 400, and 600 hours of 350nm UV light irradiation. The results were as follows. 1. According to type of pigments, after 200 hours cosmetic red showed significantly larger color change than cadmium yellow and titanium white, and after 400 and 600 hours color change significantly decreased in the order of cosmetic red, cadmium yellow, and titanium white (p<0.05). 2. In the cadmium yellow group, after 200 hours, the non-treatment group showed significantly larger color change, but after 400 and 600hours, color change significantly decreased in the order of non-treatment, surface application and mixed group (p<0.05). 3. In the titanium white group, there was no significant color change difference between the three groups after 200 and 400 hours, but after 600 hours, the mixed group showed significantly smaller color change than the non-treatment and surface application groups (p<0.05). 4. In the cosmetic red group, there was significant decrease in color change in the order non-treatment, surface application and mixed group (p<0.05). From the results above, the effect of UV light absorber differed according to the type of pigment, but mixing UV light aborber with maxillofacial silicone is thought to give superior resistance against UV light irradiation in the long run.
Cadmium ; Elastomers ; Silicones* ; Sunlight ; Titanium ; Ultraviolet Rays*

OBJECTIVEThis work explores the diurnal variation of Solar ultraviolet radiation (UVR) and total solar radiation (TSR) in northeast China, using daily observations of UVR and TSR in Shenyang.

METHODSUVR and TSR measurements were carried out from March 1st, 2006 to December 31st, 2009 in Shenyang, Liaoning province, China (41°51' N, 123°27' E).

RESULTSBoth TSR and UVR showed seasonal variation, reaching the highest levels in summer and the lowest in winter. They showed the greatest fluctuation in summer and autumn. The irradiance of TSR and UVR on clear days around the equinoxes and solstices increased substantially compared with the mean seasonal irradiance, especially in autumn. The whole day accumulated dose of UVR in winter was far less than that during the middle part of a summer day (i.e. between 10:00 and 14:00). It was also less than the accumulated summer dose of morning and afternoon (i.e. between 8:00 and 10:00 and 14:00 and 16:00).

CONCLUSIONThe instant irradiance and daily accumulated amount of UVR are low in Shenyang, especially in autumn and winter. Thus concern about the health effects arising because shortage of UVR in northeast China is warranted.

No abstract available.
Dermatitis* ; Sunlight*

No abstract available.
Internet ; Sunlight

BACKGROUND: At the entrance of a tunnel, reflection of sunlight from the surrounding environment and a lack of adequate lighting usually cause some vision problems. The purpose of this study was to perform a safety evaluation of lighting on a very long road in Ilam, Iran. METHODS: The average luminance was measured using a luminance meter (model S3; Hagner, Solna, Sweden). A camera (model 108, 35-mm single-lens reflex; Yashica, Nagano, Japan) was used to take photographs of the safe stopping distance from the tunnel entrance. Equivalent luminance was determined according to the Holliday polar diagram. RESULTS: Considering the average luminance at the tunnel entrance (116.7 cd/m²) and using Adrian's equation, the safe level of lighting at the entrance of the tunnel was determined to be 0.7. CONCLUSION: A comparison between the results of the safe levels of lighting at the entrance of the tunnel and the De Boer scale showed that the phenomenon of black holes is created at the tunnel entrance. This may lead to a misadaptation of the drivers’ eyes to the change in luminance level at the entrance of the tunnel, thereby increasing the risk of road accidents in this zone.
Iran ; Reflex ; Sunlight

BACKGROUND: Melanin pigment plays a major role in the expression of normal human skin color as well as in the photoprotection against ultraviolet damage. Melanin produced in melanocytes is transferred via dendrites to surrounding keratinocytes, and this anatomical relationship is termed as epidermal melanin unit. The rates of pigment synthesis and transfer by melanocytes appear to be influenced by ultraviolet light, though the precise factors regulating human epidermal pigmentation remain unelucidated. It has been reported that keratinocytes in vitro release factors that could modulate melanocyte behavior. Ultraviolet irradiation was also been known to enhance the release of various kinds of cytokine from keratinocytes in vivo and in vitro. OBJECTIVE: We postulated that keratinocytes rather than melanocytes could play a primary role in UVB-induced pigmentation, and keratinocytes, when irradiated with UVB, release substances that could modulate or stimulate melanin synthesis from melanocytes. The fact that keratinocytes are located efficiently for direct sunlight irradiation at the top of melanocytes, that they release various biological factors known to simulate melanin synthesis from melanocytes and that they constitute the majority of epidermal cells supported this possibility. To investigate this possibility, we evaluated the effect of supernatant from UVB-irradiated cultured keratinocytes on the growth, melanin content, and tyrosinase activity of human melanocytes. METHODS: Human cultured keratinocytes were irradiated with UVB(30, 60, or 120mj/cm2)once, and after 24 hours, supernatant of the keratinocytes were collected and added to a growth medium of melanocytes for 5 days in concentration of 15, 25 or 35%, We observed numeric and morphologic changes as well as melanin content and tyrosinase activity in situ of cultured human melanocytes. RESULTS: 1. When cultured melanocytes were incubated with supernatant of non-irradiated keratinocytes, the number of melanocytes, amount of melanin and tyrosinase activity increased in groups added with 25% or35% concentration of supernatant. 2. The number of melanocytes incubated with 15% or 25% concentrations of supernatant from cultured keratinocytes irradiated with UVB increased in both 30 and 60mj/cm2 of UVB irradiated groups and decreased in 120mJ/cm2of UVB irradiated groups. 3. The melanin content of melanocytes incubated with 15% concentration of supernatant from UVB-irradiated cultured keratinocytes increased in 120mJ/cm2 of UVG irradiated groups. 4. The tyrosinase activity of melanocytes incubated with 15% concentration of supernatant from UVB-irradiated cultured keratinocytes increased in 120mJ/cm2 of UVB irradiated groups and the tyrosinase activity of melanocytes incubated with 25% concentration of supernatant from UVB-irradiated cultured keratinocytes increased with 35% supernatant concentration of supernatant from UVB-irradiated keratinocytes, the tyrosinase activity increased in 30mJ/cm2of UVB irradiated groups. CONCLUSION: The above results suggest that UVB-irradiated kerationcytes release soluble or photoactivated factors which could modulate the growth and melanization of melanocytes, and that keratinocytes play an important or primary role in the regulation of UVB induced pigmentation.
Biological Factors ; Dendrites ; Humans* ; Keratinocytes* ; Melanins* ; Melanocytes* ; Monophenol Monooxygenase* ; Pigmentation ; Skin ; Sunlight ; Ultraviolet Rays

BACKGROUND: Bowen's disease(BD) is an in situ squamous cell carcinoma(SCC) of the skin, which clinically presents as a scaly slightly elevated erythematous plaque. Approximately two thirds of patients with BD have solitary lesions, whereas the remaining patients have multiple lesions. Lesions of BD have a wide distribution covering both sun-exposed and covered skin. Chronic sunlight exposure is an important etiological factor in many patients, and inorganic arsenicals can cause lesions on unexposed skin. If untreated, 3-5% of BD cases evolve into invasive carcinoma including SCC, basal cell carcinoma(BCC), and sebaceous carcinoma(SC), although the precise mechanism is not yet clear. OBJECTIVE: The purpose of this study was to investigate the factors which may be involved in the development of BD and progression to invasive carcinoma. METHODS: We performed immunohistochemical analysis using monoclonal antibodies for p53, mdm-2, and bcl-2 in 7 cases of multiple BD with invasive carcinoma. RESULTS: In four of 6 cases of SCC immunopositive for p53, at least one lesion of each BD was positive for p53. Among them, two cases showed the consistency of p53 staining between BD and its SCC and the localization of the lesions on sun-exposed areas. On the other hand, two cases of SCC and the associated BD were immunonegative for p53 and positive for mdm-2 and all the lesions developed on the UV-nonexposed areas. In one particular case which had a history of arsenic ingestion, SC was immunopositive for p53, whereas the associated SCC and BD were immunonegative for p53. In one case associated adenoid BCC, BD was immunopositive for p53 and negative for bcl-2, whereas BCC was immunonegative for p53 and strongly positive for bcl-2. CONCLUSION: These results suggest that UV light may play a role in the development of BD and its progression to SCC and in addition to p53, some additional factor or conditions are required in the progression towards these invasive carcinomas from BD.
Adenoids ; Antibodies, Monoclonal ; Arsenic ; Arsenicals ; Bowen's Disease* ; Eating ; Hand ; Humans ; Skin ; Sunlight ; Ultraviolet Rays

Porokeratosis is a rare epidermal disorder characterized by annular or linear hyperkeratotic plaques with slightly raised thread-like borders, and in most cases, atrophic centers. Disseminated superficial porokeratosis and disseminated superficial actinic porokeratosis (DSAP), which primarily involve sun-exposed areas, are common types of porokeratoses. Histologically, a column of parakeratotic cells, a so-called cornoid lamella, is a hallmark of porokeratosis. Porokeratosis is considered to result from the inability to eliminate an abnormal keratinocyte clone induced by genetic factors and various stimuli, including sunlight, artificial ultraviolet light, viral infections, immunosuppressive conditions (hematologic malignancies, organ transplants, or autoimmune disease), and immunosuppressive therapies. Here, we report a 59-year-old Korean woman with DSAP that developed after narrowband ultraviolet B (NB-UVB) therapy for psoriasis. Our case emphasizes the occurrence of DSAP due to NB-UVB that is able to induce local immunosuppression at the irradiated site; the pathogenesis of DSAP remains unclear.
Clone Cells ; Female ; Humans ; Immunosuppression ; Keratinocytes ; Middle Aged ; Phototherapy* ; Porokeratosis* ; Psoriasis* ; Sunlight ; Transplants ; Ultraviolet Rays ; Ultraviolet Therapy

BACKGROUND: Forty percent of solar irradiation arriving on the ground surface is infrared rays (IR). However, these have received little attention. Chronic experimental exposure to IR has been found to cause degenerative changes to dermal connective tissue and an accumulation of ground substances, which is similar to changes which occur by photoaging. OBJECTIVE: To investigate the effects of persistent heat exposure on the cutaneous aging symptoms such as wrinkles, dyspigmentation and telangiectasia. METHODS: A total of 306 male volunteers, aged between 26-68 years, were recruited from steel factories with a torrid working environment. Each volunteer was interviewed for demographic information, cumulative sunlight exposure levels and their smoking history. Skin examination and measurement of erythema/pigmentation levels were also performed on the crow's feet area of the face and/or the upper inner arm. RESULTS: 1. The group of males, aged 50years or over, who had been exposed to high temperatures for more than 10years showed a tendency to have severer wrinkles (5.1+/-1.5) than an age-matched control group (3.7+/-0.1). 2. There was no correlation between dyspigmentation and heat exposure. 3. Erythema indices decreased and were found to be dependent on the duration of heat exposure to the face in the group of males over 40years of age, and to the upper inner arm in the group of males over 50years of age. CONCLUSION: Chronic heat exposure might contribute to the development of skin wrinkles and shows the possibility of potentiation of extreme ultraviolet effects.
Aging ; Arm ; Connective Tissue ; Epidemiologic Studies* ; Epidemiology ; Erythema ; Foot ; Hot Temperature ; Humans ; Infrared Rays ; Male ; Skin Aging* ; Skin* ; Smoke ; Smoking ; Steel ; Sunlight ; Telangiectasis ; Volunteers