American Society for Photobiology

ASP Conference 2016: 21-26 May 2016
Tampa Marriott Waterside Hotel & Marina


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21 - Frontiers in models, measurement and monitoring in environmental UV

Florida 3   10:00 - 12:00

Chair(s): Jo Turner
 
21-1   10:00  Recent advances in 3d modelling of the UV body exposure A.W. Schmalwieser*, University of Veterinary Medicine, Institute of Physiology and Biophysics

Abstract: In this talk an overview in the progress of 3d modelling will be given as well as on recent developments and on future challenges. UV exposure of a human can be calculated by using 3d body models. Nowadays body models are flexible to a high degree. Models for each gender and for different ages are available. Each body model consists of tens of thousands of polygons, which deliver a realistic and detaild proxy of a body even for small parts like the ears. The posture can be changed, as well as clothing and hairstyle. Additionally the models can perform movements such as walking, running or cycling. The UV irradiance falling on a certain part of the body may result from measurements or from radiative transfer model calculations. The later enable modelling at any time and location as well as the weighting with any action spectrum. The exposure pattern differs for different action spectra. The evaluation of 3d-modelled body exposure was done in the past. Nonsurprisingly the agreement of modelled and measured values is best for clear sky. The agreement for cloudy sky depends on the time scale: as longer the period the better is the agreement. An important input parameter to the model must be delivered by studies on behaviour. Behaviour includes location, activity (postures), clothing and duration, may change fast and may have typical diurnal patterns. Recently we analysed several behaviour studies to build up a typical week at a beach resort. This includes the behaviour at the beach (e.g. walking, lying, swimming), at the hotel (e.g. balcony) and at other nearby locations (e.g. side walk cafes) in the urban environment and sports activities. It includes also the clothes worn in dependence of location, activity and time. For this a variety of postures, clothing and radiation environments were combined to calculate the UV exposure pattern of the body for a week of vacation. With that, body modelling becomes a very helpful tool for sun protection and health care.

21-2   10:20  Population UVR exposure doses are highly depended on environmental observation - based on personal UVR measurements PA Philipsen*, Bispebjerg Hospital, Copenhagen, Denmark ; M Bodekær, Bispebjerg Hospital, Copenhagen, Denmark; B Petersen, Bispebjerg Hospital, Copenhagen, Denmark; M Grage, Danish Meteorological Institute, Copenhagen, Denmark; J Heydenreich, Bispebjerg Hospital, Copenhagen, Denmark; E Thieden, Bispebjerg Hospital, Copenhagen, Denmark; P Eriksen, Danish Meteorological Institute, Copenhagen, Denmark; HC Wulf, Bispebjerg Hospital, Copenhagen, Denmark

Abstract: Personal UVR exposure is much depended on the weather, so we investigated the relation between personal UVR exposure and several meteorological observations. Personal UVR exposure was measured in Standard Erythema Doses (SED) using a wrist worn electronic dosimeter. Behaviour like work/off-work and sunbathing was recorded in a dairy on a daily basis. In May through September 2009, 44 Danish farmer families (in all 152 persons) participated in the study. Each family had 1 to 3 participating children. The mean ages for adults and children were 44 years (range 32-67 years) and 11 years (range 5-19 years) respectively. 148 people completed the study and 17303 out of the 19995 collected days were analysed. Meteorological data were collected on a daily basis for the entire period and grouped as follows: maximum temperature grouped into 5-degree intervals (<15, 15-20, 20-25, 25-30,>30 Celsius), rain grouped into two groups (above or below 1mm), sunshine-hours as high or low, cloud cover as: Clear sky, partly clouded, mostly clouded, total overcast. These meteorological parameters were used as "model input variables" to predict personal UVR exposure for farmers, spouses and children separately. The measured average UVR doses (SED) were 206.1, 143.7 and 187.6 for the farmers, spouses and children respectively. The highest personal UVR dose was on days with no rain and much sunshine (2.0 SED, ambient UVR 26.2 SED) and lowest on rainy days with less sunshine (0.7 SED, ambient UVR 15.3 SED). The percentage of ambient UVR received on days with no rain and much sunshine was 10%, significantly higher than the 5% received on less sunny and rainy days. The personal UVR was higher on days with higher temperature, but did not influence the percentage of ambient UVR received. On sunny clear sky days where ambient UVR was highest, people received not only the highest personal UVR dose but also the highest percentage of ambient UVR. (Funded by EC-project ICEPURE (227020) www.icepure.eu)

21-3   10:40  Solar UV radiation: measurement, monitoring and public awareness in sub-Saharan Africa CY Wright*, South African Medical Research Council and University of Pretoria ; PN Albers, South African Medical Research Council

Abstract: Skin cancer is an under-researched, yet important public health problem in sub-Saharan Africa where it mainly affects individuals with fair skin, individuals with oculocutaneous albinism and more recently, individuals with HIV/AIDS. A key modifiable skin cancer risk factor is exposure to solar ultraviolet (UV) radiation. Reduction of excess personal sun exposure can be achieved by altering the timing of outdoor activities and using clothing, hats, shade, and sunscreen. In the past ten years, several studies have been carried out to understand the continental status quo including systematic reviews on the health impacts of excess sun exposure, cross-sectional epidemiological studies on sunbed prevalence, adult and child knowledge and understanding of the UV Index and individual understanding of skin phototype, as well as analysis of skin cancer registry data. Together, these data provide information that can be used to inform the development of skin cancer prevention and sun awareness campaigns tailored to at-risk groups in sub-Sahara Africa.

21-4   11:00  Characterization of UV and Sun Exposure Behaviors and Skin Cancer in the Estrie Region of Quebec Province R Drouin*, Laval University, Quebec City, QC ; G Lapointe, University of Sherbrooke, Sherbrooke, QC; M Genereux, University of Sherbrooke, Sherbrooke, QC; C Bouffard, University of Sherbrooke, Sherbrooke, QC

Abstract: Since the Estrie is the region of Quebec Province with the highest incidence of skin cancer (SC), we conducted a large-scale survey on the Estrie population to characterize UV and sun exposure behaviors of people. A representative sample of 8,737 adults [≥18 years old, 4462 women (W) and 4275 men (M)] was surveyed. There were 12 questions related to the type of skin, UV exposure in tanning salon, sunbathing, risk of tanning, use of UV protection, meaning of sun tanning, number of sunburns and development of SC. Data were collected through a random digit dial telephone survey. On the Fitzpatrick scale, 17.7% of the respondents had skin types 1 and 2; 67.7% had types 3 and 4 and 14.6% had types 5 and 6. Out of 6781 adults aged between 18 and 64 years, 31% (W 44 vs. M 18%) have been to a tanning salon and 48.2% (W 60.6 vs. M 35.9%) have been sunbathing with the sole purpose of tanning. During the last 10 years, 50.7% of the respondents spent vacations in the South to catch the sun. To reduce the sun exposure, the respondent used sunscreen (79% of the respondents), clothes (72.4%), staying in the shade (74.5%) and avoiding the midday sun (63.1%). Sun tanning can mean SC (65.2%) and accelerated skin aging (62.6%) as side effects, but most respondents were there because they wanted to improve their health (63.1%), vitamin D synthesis (57.8%), relaxation (40.3%), well-being (39.6%), beauty enhancement (33.9%), treatment of skin problems such as acne or psoriasis (20.7%), seduction (16.6%), improve self-confidence (11.4%), improve chances of success (4.6%), and power (2.4%). A majority of the surveyed people consider sunburns and burns (62.8%), sun spots, changes in skin colour (53.6%), higher risks of developing SC (88.5%) and accelerated skin aging (72.9%) as risks associated with tanning. Only 4.4% of the respondents did not suffer sunburns, 48.3% (W 53.1% vs. M 43.2%) of the people had had between 1 and 9 sunburns and 47.3% (W 41.7% vs. M 53.2%) at least 10 sunburns.

21-5   11:20  Objective Assessment Of UVR-induced Erythema And Pain Sensitivity In Different Skin Types D Fajuyigbe* ; E Damato; S McMahon; G Penney; A Coleman; R Sarkany; AR Young

Abstract: Constitutive skin pigmentation is thought to be responsible for variations in response to UVR but the standard measure of sensitivity, i.e. visual assessment of the minimal erythema dose (MED) may be obstructed by high levels of melanin (dark skin). Our aim was to explore confocal microscopy using its 830nm wavelength (minimally absorbed by melanin) to analyse erythema irrespective of skin colour. Volar forearms of healthy African (type VI) and fair-skinned volunteers (types I/II) were exposed to a geometric dose series of solar simulated radiation. Exposures were based on standard erythema doses(SED). 24h post-exposure, blood vessels videos were captured within a 0.5x0.5mm^2 frame and the blood vessel area and blood cell counts per second (flow) were automatically extracted. We found a significant linear correlation between vessel area and SED for black (p=0.0005,slope=0.0023) and white skin (p=0.0001,slope=0.0943) thus suggesting that white skin is roughly 40 times more sensitive to UVR. Further analysis showed significant correlation between flow and area for white (R^2=0.903,p=0.001) and black skin (R^2=0.562,p=0.03). It is clear that confocal microscopy offers a novel approach for the objective determination of sensitivity to UVR irrespective of skin colour. Furthermore, on the same skin sites, we assessed skin type differences in the relationship between visible erythema and pain sensitivity using thermal and mechanical stimuli. The baseline thermal sensitivity threshold was 47.80^oC±0.42 with no significance difference between black and white skin (p=0.32). When SSR exposure was expressed as MED, there was no skin type difference (p=0.0001) in increased sensitivity to thermal pain. However, black skin unlike white skin showed resistance to mechanical stimuli regardless of dose (p=0.78). These results extend the previous findings of erythema and pain sensitivity correlations in white skin, it remains unclear why black skin was resistant to mechanical stimuli.

21-6   11:40  Using Smartphone Hardware To Measure Ultraviolet Radiation. J Turner*, University of Southern Queensland ; AV Parisi, University of Southern Queensland; D Igoe, University of Southern Queensland; A Amar, University of Southern Queensland

Abstract: Smartphones are increasingly being used to provide people with the Ultraviolet Index (UVI) values and help them control their ultraviolet (UV) exposure. Various approaches have been applied to provide this service, some of which include external sensors and algorithm based prediction systems (Apps). Whilst these are excellent methods to improve education and understanding about UV exposure, one of the areas where the current products commercially available fail, (when no external sensor is available either due to availability or financially) is to account for areas where connectivity is intermittent or non-existent for an app that relies on network based information. In regional and remote areas of Australia, connectivity can still be an issue. In most UVI algorithm applications, the calculation of UVI is achieved from data collected in the nearest largest city that has the appropriate weather data collection systems. For some areas this could be an inappropriate estimation and provide incorrect UVI values. Additionally it fails to account for factors such as variation in cloud compared to location, and proximity of structures in the landscape. In order to determine UVI correctly, measurement of UVB radiation as well as UVA radiation is required. Previous work has shown it is possible to detect UVA radiation with existing hardware already contained within a smartphone (Igoe, Parisi & Carter, 2013). To measure UVI using existing smartphone hardware, UVB radiation must also be detectable within the same system. The feasibility of the use of smartphone hardware will be discussed and the smartphone's sensitivity to UVB radiation will be presented by considering data collected on the dark response, temperature response, irradiance response and spectral response for three different smartphone models. Discussion will also be included on the feasibility of the use of the smartphone as a UV measurement tool. Igoe, D., A. Parisi and B. Carter (2013)Photochem. Photobiol., vol. 89, pp. 215-218.



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