Personal UV exposure in high albedo alpine sites

[摘要] Mountain sites experience enhanced UV radiation levels due to the concurrenteffects of shorter radiation path-length, low aerosol load and highreflectivity of the snow surfaces. This study was encouraged by thepossibility to collect original data of personal dose on a specificanatomical site (erythemally effective UV dose on the forehead) of twogroups of volunteers (ski instructors and skiers) in the mountainous areasof Italy (the Alpine site of La Thuile-Les Suches in Valle d'Aosta region).Personal doses were assessed using polysulphone dosimetry. Exposure Ratio(ER), defined as the ratio between the personal dose and the correspondingambient dose (i.e. erythemally weighted dose received by a horizontalsurface) during the same exposure period was taken into account. In additionmeasuring skin colours as biological markers of individual response to UVexposure, was also carried out on the forearm and cheek of each volunteerbefore and after exposure.

The median ER, taking into account the whole sample, is 0.60 in winter, witha range of 0.29 to 1.46, and 1.02 in spring, ranging from 0.46 to 1.72. Nodifferences in ERs were found between skiers and instructors in spring whilein winter skiers experienced lower values.

Regarding skin colorimetric parameters the main result was that both skiersand instructors had on average significantly lower values of luminance afterexposure i.e.~they became darker. It was found that the use of sunscreen andindividual skin photo-type did not produce significant variations in ERacross instructor/skier group by day and by seasons (p>0.05). It seems thatsunscreen use only at the beginning of the exposure or in a few cases acouple of times during exposure (at difference with the specificinstructions sheets), was not sufficient to change significantly skincolorimetric parameters across participants.

In conclusion UV personal doses on the ski-fields are often significantlyhigher than those on horizontal surfaces and consistently more intenserespect to personal doses received by sunbathers on the beach in centralItaly (ER range: 0.09–0.42). Given the high levels of exposure observed inthe present study, specific public health warnings with regards to theefficacy of sun-protection behaviours (proper application and re-applicationof sunscreen and protective measures such as hats and sun glasses) should beadopted.

[学科分类] 大气科学