Department of Agrifood Production and Environmental Sciences, University of Florence, Piazzale delle Cascine 18, 50144 Florence, Italy; Interdepartmental Centre of Bioclimatology, University of Florence, Firenze, Piazzale delle Cascine 18, 50144 Florence, Italy; Center for Civil Protection and Risk Studies, University of Florence (CESPRO), Viale Morgagni 48, 50134 Florence, Italy.
Institute of Biometeorology, National Research Council, Florence, Via Giovanni Caproni 8, 50145 Florence, Italy; LaMMA Consortium (Environmental Modelling and Monitoring Laboratory for Sustainable Development), Via Madonna del Piano, 10, 50019 Sesto Fiorentino, Florence, Italy.
J Photochem Photobiol B. 2014 Jan 5;130:338-48. doi: 10.1016/j.jphotobiol.2013.12.009. Epub 2013 Dec 24.
Erythema is the most familiar short-term symptom of human skin associated with overexposure to unperceivable ultraviolet radiation (UV). However, people are able to perceive the warm infrared component of the solar radiation by means of thermal (dis)comfort. This study investigated the potentiality of perceived outdoor heat stress as a valuable proxy for the unperceivable effect of UV-induced risk of erythema in a Mediterranean city. Meteorological data and UVB (280-320nm) measurements were obtained for the 2004-2012 period by a weather station located in the municipality of Florence. Continuous measurements of erythemally effective UV (UVEry) were performed by means of a broadband temperature-corrected radiometer with the spectral response close to the erythemal action spectrum. Hourly UVEry doses were expressed as Standard Erythemal Doses (SEDs). The newly developed Universal Thermal Climate Index (UTCI), that represents the state-of-the-art of outdoor thermal (dis)comfort evaluation, was also assessed. Descriptive analyses of the hourly distribution per month of the frequencies of days with heat stress and UVEry exceeding 2.0, 3.0, 4.5 and 6.0 SEDs were carried out based on the general skin-type characteristics. The association between UVEry and UTCI was analyzed by a two-way contingency table approach. The probability of UVEry exceeding specific SED thresholds when heat stress occurs was often significantly higher than the same probability when no heat stress is perceived. Furthermore, increased magnitudes of the ratios, ranging from the very sensitive to the minimally sensitive skin types, were also found. However, during several months, too many days occur without any signs of heat discomfort, even when people may be exposed to relevant doses of harmful UVEry for the skin of various phototypes. These findings underlie the need for public health authorities to provide differentiated advice per month in relation to potential UV skin damage in the city of Florence.
红斑是与不可察觉的紫外线辐射（UV）过度暴露相关的人类皮肤最常见的短期症状。然而，人们能够通过热（不适）感来感知太阳辐射的温暖红外线成分。本研究调查了感知到的室外热应激作为地中海城市中不可察觉的 UV 诱导红斑风险的有价值替代指标的潜力。气象数据和 UVB（280-320nm）测量值是通过位于佛罗伦萨市的气象站在 2004-2012 年期间获得的。通过具有接近红斑作用光谱的光谱响应的宽带温度校正辐射计连续测量有效红斑紫外线（UVEry）。每小时 UVEry 剂量表示为标准红斑剂量（SEDs）。还评估了新开发的通用热气候指数（UTCI），它代表了室外热（不适）感评估的最新技术。根据一般皮肤类型特征，对每月每小时分布的热应激和 UVEry 超过 2.0、3.0、4.5 和 6.0 SED 的天数频率进行了描述性分析。通过双向列联表方法分析了 UVEry 和 UTCI 之间的关系。当发生热应激时，UVEry 超过特定 SED 阈值的概率通常明显高于没有热应激时的相同概率。此外，还发现了从非常敏感到最小敏感皮肤类型的比值增加幅度。然而，在几个月中，即使人们可能会暴露在各种光型皮肤的有害 UVEry 的相关剂量下，也会有太多天没有任何热不适的迹象。这些发现强调了公共卫生当局有必要根据佛罗伦萨市的潜在 UV 皮肤损伤每月提供差异化建议。
