Poisonous books are lurking inside this London, Ont., library

Kendra Seguin · CBC News

· Posted: Nov 06, 2025 5:00 AM EST | Last Updated: November 6

When Western University pupil Karen Wen archetypal saw a agleam achromatic pigment wrong an aged manuscript she was reading, she was alarmed.

The vibrant shadiness reminded her of toxic pb paint.

“It conscionable felt truthful jarring that lead, oregon what perchance mightiness beryllium lead, was close successful beforehand of maine and close successful beforehand of my fingertips,” Wen said.

What started arsenic interest rapidly turned to curiosity, and Wen started seeking retired akin books crossed the university’s libraries. In 4 months, she identified 96 “poison books” that incorporate arsenic, a notoriously toxic constituent that is unsafe to humans.

“Maybe that statement of ‘poison’ is simply a immense alarm for america erstwhile we brushwood arsenic, but backmost past it was known arsenic poisonous, but not successful the aforesaid mode we cognize it today,” said Wen, a 3rd twelvemonth English pupil successful Western’s School for Advanced Studies successful Arts and Humanities.

Karen Wen is simply a third-year English pupil successful the School for Advanced Studies successful the Arts and Humanities astatine Western University successful London, Ont. She spent the summertime researching and identifying poison books passim the university's libraries. (Submitted by Karen Wen)

Wen’s probe focused connected Victorian-era books containing copper-arsenic compounds successful the covers, spines and bindings. 

Some titles see The Sportman's Gazetter, Catskill Fairies and Cornet of Horse. The books each person a agleam emerald greenish exterior, which Wen said was fashionable for aesthetic reasons successful the 19th century, careless of the perchance harmful effects. 

“After tons of modern probe that we person connected arsenic arsenic an element, we spot it otherwise than radical did backmost then,” she said, adding that it was commonly utilized successful wallpaper, toys and soap.

A larger task astatine the University of Delaware called the Poison Book Project was the launching constituent for Wen’s investigation. She utilized immoderate of the project’s resources, specified arsenic an online poison publication database and a peculiar colour swatch bookmark, to comparison known toxic books to those astatine Western. 

Karen Wen visited the Earth and Planetary Materials Analysis Laboratory astatine Western University to trial imaginable poisonous books. Lab technicians scanned the country indicated by a yellowish box, and recovered arsenic and gold. (Submitted by Earth and Planetary Materials Analysis Laboratory, Western University)

After pulling retired perchance poisonous books from D.B Weldon Library, Huron University College Library, and the Archives and Special Collections Library, Wen combined her emotion for lit with subject and got them tested successful a lab. 

Working with technicians astatine Western’s Earth and Planetary Materials Analysis Laboratory, Wen utilized a method called X-ray fluorescence spectroscopy to scan the books for perchance toxic elements, and galore came backmost affirmative for some copper and arsenic. 

How unsafe are the books?

Special collections and uncommon books librarian Deborah Meert-Williston said she’s known poisonous books person been lurking successful Western’s collection, but contempt the name, they’re not arsenic unsafe arsenic they whitethorn seem.

“I would accidental you wouldn’t privation to instrumentality 1 of these books location and person a toddler chew connected it, your favored chew connected it oregon thing similar that,” Meert-Williston said. “But, for the astir part, they’re not truly dangerous. They’re conscionable thing you privation to beryllium alert of, arsenic with immoderate antique oregon thing that you person successful your location that has colouring oregon different kinds of chemicals successful them.”

Deborah Meert-Williston is the Special Collections and Rare Books Librarian astatine Western University successful London, Ont. A caller pupil task recovered determination are astir 100 books successful Western's postulation that incorporate arsenic, specified arsenic the 1 Meert-Williston holds successful her gloved hands. (Kendra Seguin/CBC News)

At Western, each perchance poisonous books person been placed wrong polyethylene bags with a enactment letting readers cognize they could incorporate arsenic and to beryllium cautious, Meert-Williston said.

Some champion practices see washing your hands aft usage and avoiding rubbing your eyes oregon putting your hands adjacent your rima portion reading, said Wen.

Toxic materials archer different story

Meert-Williston said it is communal signifier for immoderate librarians to regenerate aged oregon damaged publication covers, but she said it comes astatine a cost: losing the book’s carnal history.

“As a uncommon publication librarian, I travel astatine the publication arsenic a carnal object. The publication tells america truthful overmuch by its appearance; from its size, to however decorative it is, to however overmuch wealth was spent to marque it,” she said.

Meert-Williston said she plans to support Western’s poison publication postulation intact and disposable to funny readers. It’s thing that Wen said is important for anyone who wants a glimpse into the past.