Apparently it doesn't, according to the resuts of a test, as reported in a medical journal:
http://www3.interscience.wiley.com/cgi-bin/fulltext/86510619/PDFSTART?CRETRY=1&SRETRY=0
http://www3.interscience.wiley.com/cgi-bin/fulltext/86510619/PDFSTART?CRETRY=1&SRETRY=0