Why old books can literally be poisonous

By Stephen Beech via SWNS

Old books can be poisonous - literally, warns new research.

Some tomes that are over 100 years old contain toxic dyes - including lead and chromium up to six times above acceptable legal levels, say scientists.

They warned people to "handle with care" or even steer clear altogether of any brightly colored, cloth-bound books from the Victorian era.

Some of their attractive hues come from dyes that could pose a health risk to readers, collectors or librarians., reveals the new study.

American researchers used three techniques - including one that hasn’t previously been applied to books - to assess dangerous dyes in a university collection - and found some volumes may be unsafe to handle.

Their findings led to some books being removed from library shelves while others dating from the 19th Century that have not yet been tested have been sealed in plastic zip-close bags for handling and storage.

Research co-author Abigail Hoermann, of Lipscomb University in Nashville, said: “These old books with toxic dyes may be in universities, public libraries and private collections.

”Users can be put at risk if pigments from the cloth covers rub onto their hands or become airborne and are inhaled.

“So, we want to find a way to make it easy for everyone to be able to find what their exposure is to these books, and how to safely store them.”

Chemistry undergraduate Hoermann, recent graduate Jafer Aljorani, and fellow undergraduate Leila Ais have been conducting the study with Dr. Joseph Weinstein-Webb, an assistant chemistry Professor at Lipscomb.

The study began after Lipscomb librarians Jan Cohu and Michaela Rutledge approached the University’s chemistry department to test brilliantly colored 19th-century and early 20th-century fabric-covered books from the school’s Beaman Library.

Dr. Weinstein-Webb was intrigued to hear about how the Winterthur Museum, Garden and Library had previously examined its own 19th Century books for the presence of an arsenic compound known as copper acetoarsenite.

The emerald-green pigment was used in Victorian-era wallpaper, garments and in cloth book covers.

The discovery led to the launch of the Poison Book Project that uses X-ray fluorescence (XRF), Raman spectroscopy and other techniques to reveal toxic pigments in books around the world.

Dr Weinstein-Webb and the Lipscomb students he recruited launched their own investigation in 2022.

For the Lipscomb book project, the team used XRF to qualitatively check whether arsenic or other heavy metals were present in any of the book covers.

Inductively coupled plasma optical emission spectroscopy (ICP-OES) was employed to determine the concentration of those metals, while X-ray diffraction (XRD) was used to identify the pigment molecules that contain those metals.

Although XRD has been previously used to examine paintings and wallpaper, Ais says the new study was the first time it has been used to check for poison in books.

The team used XRF data to show that lead and chromium were present in some of the Lipscomb books.

To quantify the amounts, they snipped samples around the size of a small paperclip from the cloth covers and then dissolved them in nitric acid.

Their analysis by ICP-OES showed that lead and chromium were both present in "high" levels in some samples.

Subsequent XRD testing indicated that in some instances the heavy metals were in the form of lead(II) chromate, one of the compounds that contribute to the chrome yellow pigment favored by Vincent van Gogh in his sunflower paintings.

But there was far more lead than chromium in the book covers, which was intriguing since lead(II) chromate contains equal amounts of lead and chromium.

The research team suspects that the dyes used to color the books contain other lead-based pigments that lack chromium, such as lead(II) oxide or lead(II) sulfide.

Now they are working to identify other compounds in the yellow pigments.

Dr. Weinstein-Webb and the students also wanted to find out whether the levels of heavy metals in the Lipscomb books could be harmful to librarians who might handle them.

They discovered in some book covers metal concentrations above acceptable legal limits for chronic exposure.

In the dissolved sample from the most contaminated cover, the lead concentration was more than twice the Centers for Disease Control and Prevention (CDC) limit, while the chromium concentration was almost six times the limit.

Chronic exposure to inhaled lead or chromium could lead to health issues including cancer, lung damage or fertility issues.

Dr. Weinstein-Webb said: “I find it fascinating to know what previous generations thought was safe, and then we learn, oh, actually, that might not have been a great idea to use these brilliant dyes.”

The findings led the Lipscomb library to seal colorful 19th-century books that have not yet been tested in plastic zip-close bags for handling and storage.

Books confirmed to contain dangerous dyes were also sealed in bags and removed from public circulation.

Hoermann added: “Moving forward, we want libraries to be able to test their collections without destroying them.”

The researchers presented their findings at a meeting of the American Chemical Society (ACS) in Denver, Colo.