The racy novel, Fifty Shades of Grey, has gotten even dirtier, after Belgian university professors found traces of cocaine and the herpes virus on the book.

Toxicologist Professor Jan Tytgat of the Catholic University of Leuven decided to test 10 of the most borrowed books from the Antwerp lending library. What he found was astonishing — there were trace amounts of cocaine and the herpes virus on the popular E. L. James novel.

"The levels found won't have a pharmacological effect. Your consciousness or behavior won't change as a result of reading the tomes," Tytgat said.

Another research team set out to determine how dirty their library books were. In 2011, students from Brigham Young University (BYU) found that their library books which, were in high demand, had an average of 25 to 40 percent more microbial life than those that might have been forgone, according to one of the researchers, Joshua Nicholson.

The type of herpes virus that was found on the book was herpes simplex virus type 1, the strain of herpes responsible for cold sores or fever blisters. Readers should not be too alarmed as the herpes virus does not live very long outside the body, and the viruses did not pose any significant health issue because the concentrations were so low.