When we’re previously referred to 50 Shades of Grey as a ‘dirty’ book, we meant it in the juvenile, ‘sexy bits’ kind of way. Not so for Professor Jan Tytgat, a toxicologist based in Antwerp, Belgium, who got a mad notion to see what kind of nasties could be found in library books, and in particular the breakout ‘mummy porn’ novel of the last decade. Tygat visited his local library and took the current ten most popular books out on loan, along with some comparison novels that spend most of their time gathering dust on the library shelves. It might not come as a surprise that the more popular reads had between 25 and 40 per cent more bacteria than the dust-gatherers, but it might be a little more shocking to hear what else was found on the books. All ten of the popular reads tested positive for cocaine, much like most paper currency in the world. Don’t worry though, you won’t get out of your mind by sniffing a copy of Gone Girl, the levels found were not enough to get readers of the borrowed book high, yet significant enough to make them test positive for the drug. Professor Jan Tytgat explained: "Today's testing methods are so sensitive that traces of the drug originating from a contaminated book will be found in your hair, blood and urine." Just try getting anyone to believe you were sitting at home reading a library book after you test positive for cocaine. Good luck with that. Worse still were the further findings on 50 Shades of Grey, which tested positive for oral herpes. The good news? The levels were so low that professors deemed it ‘practically impossible’ to contract from the book. Practically.