title: Might outdoor heat stress be considered a proxy for the unperceivable effect of the ultraviolet-induced risk of erythema in Florence?
abstract: 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.
authors.affiliation: 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. Electronic address: marco.morabito@unifi.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Morabito
authors.affiliation: 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.
authors.forename: Daniele
authors.initials: D
authors.lastname: Grifoni
authors.affiliation: Institute of Biometeorology, National Research Council, Florence, Via Giovanni Caproni 8, 50145 Florence, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Crisci
authors.affiliation: 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.
authors.forename: Luca
authors.initials: L
authors.lastname: Fibbi
authors.affiliation: 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.
authors.forename: Simone
authors.initials: S
authors.lastname: Orlandini
authors.affiliation: Clinica Medica e Cardiologia, University of Florence, Viale Morgagni 85, 50134 Florence, Italy.
authors.forename: Gian Franco
authors.initials: GF
authors.lastname: Gensini
authors.affiliation: Institute of Biometeorology, National Research Council, Florence, Via Giovanni Caproni 8, 50145 Florence, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Zipoli
mesh_terms: D004890:Erythema / Q000209:etiology*; D018882:Heat Stress Disorders / Q000209:etiology*; D006358:Hot Temperature; D006801:Humans; D007558:Italy; D008962:Models, Theoretical; D012867:Skin / Q000473:pathology / Q000528:radiation effects*; D012984:Software; D014466:Ultraviolet Rays / Q000009:adverse effects*; D055548:Vapor Pressure; D014919:Wind
keywords: Air temperature; Heat discomfort; Solar radiation; Standard Erythemal Dose; UVB; Universal Thermal Climate Index