Erotica readers get more "dirty" than they bargain for (Flickr / katybird).

Fifty Shades of Grey by E. L. James has received much media attention since its release in 2011. The erotic romance novel has sold 16 million copies in the United States and has become the fastest selling paperback book in history. It topped the charts for best selling book in the U.S. when it was the first book to sell more than 1 million copies on the Amazon Kindle. Its popularity continues two years after its release, making it one of the most checked-out books in public libraries.

Two Belgian university professors decided to run toxicology and bacteriology screenings on the 10 most borrowed books in the Antwerp library to determine what kinds of germs could be found on library books. Fifty Shades of Grey was among this list. Their results were astounding.

All ten books contained traces of cocaine, which was enough to make a person test positive for the drug. Toxicologist Professor Jan Tygat of the Catholic University of Leuven said, “The levels found won’t have a pharmological effect… 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.”

Not only did the professors find traces of cocaine in the books, they also discovered the presence of the herpes virus on Fifty Shades of Grey. But the professors ensured that the concentrations of the viruses were too low to pose any real danger to one's health.

The next time you are considering borrowing a book, you may want to ponder the possible germs and viruses that could be haunting the pages. Maybe investing in the book at a bookstore would be a cleaner, safer bet?

Reach Staff Reporter Niki Hashemi here or follow her on Twitter.