Scientists Reveal How To Spot Toxic 'Poison Books'

Toxic books are in the news after four arsenic-laced volumes were quarantined from the shelves of France's national library. But how dangerous are these books? And how can you spot them?

Newsweek asked Melissa Tedone, an Assistant Professor of Library and Archives Conservation at the University of Delaware and joint leader of the Poison Book Project.

"Human beings have made material culture for millenia," Tedone told Newsweek. "And we have been using potentially toxic ingredients like heavy metal pigments for nearly as long."

Together with her research partner Rosie Grayburn, Tedone studies these heavy metal pigments in 19th-century bookbindings, which is when the toxic book trade really took off.

"Heavy metal pigments were popular in art, books, wallpapers, and other domestic products in the 19th century because they were so vibrant," Tedone said. "Two of the most 'poisonous' of those pigments are emerald green, which contains arsenic, and chrome yellow, which contains lead and chromium."

These heavy metal pigments stopped being used around the turn of the 20th century because new, synthetic dyes were invented that were still brightly colored and lightfast, but much less toxic. But how dangerous are these "poisonous" books, really?

"For skin exposure to cause problems, you would probably need to handle lots of emerald green books over long periods of time," Tedone said. "The more serious concern is accidentally transferring arsenic to your mouth, nose, or eyes with contaminated hands.

"Our testing shows that an invisible but significant amount of arsenic transfers onto the hands when emerald green bookbindings are handled. That is why we recommend people wear nitrile gloves to handle these books, and to wash hands thoroughly with soap and water after handling, even if you've worn gloves. If a toddler or pet were to put an emerald green book in their mouth, then that could be really dangerous.

"For books that contain lead and chromium, so far we are not detecting any transfer of those heavy metals onto the skin when the book is touched. So, it's OK to handle those books without gloves. It's just always a good idea to wash your hands afterwards!"

As part of the Poison Book Project, Tedone and Grayburn identify and catalog books known to contain these toxic substances. "So far, these books have been identified in secondhand bookstores and libraries in Europe, North America, Australia, and New Zealand," Tedone said.

"We have a website that shares our research to date [and] we also maintain the Arsenical Book Database, which is our crowdsourced inventory of books that have been confirmed to contain arsenic in the form of emerald green pigment. Over 250 arsenical books have been positively identified so far."

So how can you spot these "toxic" books? Tedone pointed to a few giveaways:

• Date: "The 19th century is a sort of 'sweet spot,' if you will, for toxic pigments in bookbindings."
• Color: "Vivid green cloth bookbindings from the 1840s to 1860s are probably the biggest hazard, because they contain so much arsenic in the cloth, and the pigment offsets onto the hands so easily."
• Country of origin: Arsenic is primarily used in British and North American imprints.

If you think you might have a toxic book, you can compare it to the list of titles in the Poison Book Project database. But should you be worried?

"I encourage anyone who may have an emerald green bookbinding in their collection—whether home or library—not to panic," Tedone said. "The biggest risk these books present is simply not knowing they contain arsenic. Once the risk is recognized, it is easy to store and handle these books safely."

Safety tips include handling with nitrile gloves and storing arsenic books in a zip-lock plastic bag to contain any shedding pigment. (And needless to say, keep out of reach of children.)

"These bookbindings are a strange and provocative piece of history," Tedone said. "They should be preserved and appreciated (carefully!)"