{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T13:26:49Z","timestamp":1788269209691,"version":"build-2803163510"},"reference-count":34,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2023,5,5]],"date-time":"2023-05-05T00:00:00Z","timestamp":1683244800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>UV radiation is used for sterilization but has adverse health effects in humans. UV-A radiation has lower antimicrobial effect than UV-B and UV-C but constitutes a lower health risk, opening up the possibility to sanitize environments with human presence in controlled exposure conditions. We investigated this possibility by identifying safe exposure conditions to a UV-A lamp along with efficient sanitization of the environment. The human exposure limits were calculated following the guidelines provided by the International Commission on Non-Ionizing Radiation Protection and the International Commission on Illumination. Antibacterial activity was evaluated on Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The maximum human exposure duration has been identified at different irradiation distance and angle, increasing with the increase of both parameters. Bactericidal activity was observed in all microorganisms and was higher with higher exposure time and at lower distance from the source. Noteworthily, in equal conditions of radiant exposure, the exposure time impacts on the bactericidal activity more than the distance from the source. The modulation of factors such as distance from the source, exposure time and irradiation angle can enable effective antibacterial activity and human safety. Prolonged direct irradiation of the surfaces associated with indirect human exposure represents the condition of greater efficacy and safety.<\/jats:p>","DOI":"10.3390\/ijms24098331","type":"journal-article","created":{"date-parts":[[2023,5,8]],"date-time":"2023-05-08T03:34:53Z","timestamp":1683516893000},"page":"8331","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["UV-A Radiation: Safe Human Exposure and Antibacterial Activity"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5107-0960","authenticated-orcid":false,"given":"Angela","family":"Sandri","sequence":"first","affiliation":[{"name":"Department of Diagnostics and Public Health, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aldo","family":"Tessari","sequence":"additional","affiliation":[{"name":"FOR ALL Srl, Via 8 Marzo 10-12, Bussolengo, 37012 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Danilo","family":"Giannetti","sequence":"additional","affiliation":[{"name":"Agilux Srl, Via Augusto Anfossi 19, 20135 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alberto","family":"Cetti","sequence":"additional","affiliation":[{"name":"FOR ALL Srl, Via 8 Marzo 10-12, Bussolengo, 37012 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria M.","family":"Lleo","sequence":"additional","affiliation":[{"name":"Department of Diagnostics and Public Health, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9623-6859","authenticated-orcid":false,"given":"Federico","family":"Boschi","sequence":"additional","affiliation":[{"name":"Department of Engineering for Innovation Medicine, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,5,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3888","DOI":"10.1128\/aem.56.12.3888-3889.1990","article-title":"Bactericidal effectiveness of modulated UV light","volume":"56","author":"Bank","year":"1990","journal-title":"Appl. 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