On Wed, 22 Apr 2020 10:39:56 -0700 Jerry Herrman via Mercedes <mercedes@okiebenz.com> wrote:
> I did not know where to get this question answered so I decided to > submit it to the boys at The Mercedes Digest. Somebody there surely > knows the answer. After all, it is an automotive question, right? > > After wearing my COVID face mask in the car, I leave it on the > dashboard so the sun's rays have an opportunity to kill any harmful > microbes that may be present. Which brings up the question of whether > or not the ultraviolet rays can penetrate glass, specifically > automotive windshield glass. It is my understanding that to kill > microbes, a wavelength of 254 nanometers is necessary, most of which > doesn't make it to earth. So is this a useful practice or a fool's > errand? Sorry, Jerry, it's a fool's errand. It was tested in 2003 and that with the right kind of cars! Craig https://www.ncbi.nlm.nih.gov/pubmed/12925188/ Photodermatol Photoimmunol Photomed. 2003 Aug;19(4):175-81. UV exposure in cars. Moehrle M[1], Soballa M, Korn M. [1] Department of Dermatology, University of Tuebingen, Germany. matthias.moeh...@med.uni-tuebingen.de Abstract BACKGROUND: There is increasing knowledge about the hazards of solar and ultraviolet (UV) radiation to humans. Although people spend a significant time in cars, data on UV exposure during traveling are lacking. The aim of this study was to obtain basic information on personal UV exposure in cars. METHODS: UV transmission of car glass samples, windscreen, side and back windows and sunroof, was determined. UV exposure of passengers was evaluated in seven German middle-class cars, fitted with three different types of car windows. UV doses were measured with open or closed windows/sunroof of Mercedes-Benz E220T, E320, and S500, and in an open convertible car (Mercedes-Benz CLK). Bacillus subtilis spore film dosimeters (Viospor) were attached to the front, vertex, cheeks, upper arms, forearms and thighs of 'adult' and 'child' dummies. RESULTS: UV wavelengths longer than >335 nm were transmitted through car windows, and UV irradiation >380 nm was transmitted through compound glass windscreens. There was some variation in the spectral transmission of side windows according to the type of glass. On the arms, UV exposure was 3-4% of ambient radiation when the car windows were shut, and 25-31% of ambient radiation when the windows were open. In the open convertible car, the relative personal doses reached 62% of ambient radiation. CONCLUSIONS: The car glass types examined offer substantial protection against short-wave UV radiation. Professional drivers should keep car windows closed on sunny days to reduce occupational UV exposure. In individuals with polymorphic light eruption, produced by long-wave UVA, additional protection by plastic films, clothes or sunscreens appears necessary. PMID: 12925188 DOI: 10.1034/j.1600-0781.2003.00031.x ===================================================================== Go to https://www.ncbi.nlm.nih.gov/pubmed/12925188/?report=docsum for a listing of similar articles and their links: Ultraviolet radiation penetrating vehicle glass: a field based comparative study.[Phys Med Biol. 1999] Implication for photosensitive patients of ultraviolet A exposure in vehicles.[Br J Dermatol. 2004] Use of UV-protective windows and window films to aid in the prevention of skin cancer.[J Long Term Eff Med Implants. ...] Review Broad-spectrum photoprotection: the roles of tinted auto windows, sunscreens and browning agents in the diagnosis and treatment of photosensitivity. [Dermatology. 1992] Review Current status of photoprotection by window glass, automobile glass, window films, and sunglasses. These would seem to provide more and more definitive information. _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
