Books in the library of the Heinrich Heine University Düsseldorf (symbolic image)

Photo: Maja Hitij/dpa

Because individual books from the 19th century could be contaminated with toxic arsenic, the Düsseldorf University Library is temporarily removing 15,000 books from its inventory.

There are fears that the works may contain arsenic compounds because the toxic substance was sometimes used in green dyes used at the time.

The library at Heinrich Heine University is following the example of other institutions with historical books on their shelves, such as the university libraries in Siegen and Bielefeld.

“As long as the books are on the shelf, they do not pose a health risk,” the library said in a statement.

Theoretically, however, there could be a danger "if volumes published in the 19th century with green components are touched and the fingers are even moistened with the tongue to turn the pages."

It is also conceivable that dust containing arsenic on the volumes may be inhaled or that arsenic may get into the eyes when touching the volumes.

However, no specific cases of poisoning have been reported yet.

Four locations will be temporarily closed

In order to be able to sort out and examine the books, the central library and some specialist libraries will be completely closed from March 18th to 22nd.

The closure is necessary so that the potentially contaminated books can be removed quickly and safely from the freely accessible area.

“We will look through the 15,000 volumes from the 19th century in the open access area as quickly as possible, remove potentially contaminated volumes and initially store them for subsequent testing,” says Kathrin Kessen, director of the library.

»How many of the books actually have arsenic contamination can only be quantified after testing.

We are calculating with a low four-digit number.«

While books classified as harmless should be made usable again as quickly as possible after the tests, the handling of contaminated volumes - for example in the form of special protective measures - still needs to be discussed.

Overall, it is a theoretical danger; sorting out the volumes is "purely - but necessary - a precautionary measure" to protect health.

At the University of Siegen, 12,000 books are currently suspected of containing arsenic; in Bielefeld, according to a statement from the university, there are even 60,000 volumes.

him/dpa