Toxic chemicals are found in more than 200 19th-century books  ... here is how YOU can spot a 'deadly' edition

Scientists have now found traces of the toxic chemical, arsenic, in the covers of more than 200 books from around the world.

Old books from the 19th-century featured green covers with worrying levels of arsenic, prompting some libraries to remove them from the shelves.

Book titles produced in the mid-1800s included 'The Complete Poetical Works of William Cowper, Esq' (1845), 'The Liberty Bell' (1856) and 'A Winter Wreath of Summer Flowers' (1855).

Researchers at the University of  Delaware as also identified red and yellow covers that contain levels of mercury and lead using X-rays to test the chemical compounds.

Scientists are now warning the public to be on the lookout for the tainted works, saying exposure could cause respiratory issues, lesions and cancer. 

19th century books clad in green covers could contain arsenic which is a highly toxic chemical linked to stomach cancer and hand lesions Pictured: books that were found to contain arsenic

The emerald green pigment, also called Paris green and Scheele green, were found in more than 200 books around the world

Scientists warn that you should wear gloves when handling books that could contain the green dye containing arsenic and wash your hands immediately after touching the book Pictured: a book containing arsenic at the Leeds Central Library

Victorian-era publishers started mass producing books in the early 1800s, but it became expensive because titles were historically created with leather covers.

The book publishers instead created book covers that contained green dye because it was a cheaper alternative to leather, but they were unaware the arsenic used to make the dye could be fatal.

The publishers chose to use bright colors like vivid green which was called Paris green, emerald green or Scheele's green after the chemist who discovered arsenic, to attract readers.

These books are still prevalent in libraries today, hiding among the swaths of volumes at institutions around the world, and as each is discovered, its placed in a quarantine-style environment for further analysis.

Last week, France's National library removed four of its books with emerald green covers that are believed to contain arsenic and while they would likely cause only minor harm, the library is conducting tests before considering placing them back on the shelves. 

Researchers flagged the titles including the 1862-1863 book of the Horticultural Society and two volumes of Edward Hayes's 'The Ballads of Ireland' from 1855.

'We have put these works in quarantine and an external laboratory will analyze them to evaluate how much arsenic is present in each volume,' the library told The Guardian.

Arsenic exposure has been linked to increased respiratory symptoms, poor lung function and chronic lung disease but long-term exposure could lead to skin lesions and cancer.

Arsenic exposure has been linked to increased respiratory symptoms, poor lung function and chronic lung disease but long-term exposure could lead to skin lesions and cancer. Pictured: An illustration of what a person's hands looked like after extensively handling objects containing the arsenic-laden green dye

Arsenic was used to create green dye in the early 1800s as a cost-effective alternative to creating leather-clad titles. Pictured: Museums Victoria's library manager Hayley Webster handles an arsenic-coated book from the rare book collection

Carl Wilhelm Scheele was a German chemist who discovered that by mixing copper and arsenic, he could create the eye-popping green dye in 1775.

This variation was eventually discarded because of its tendency to fade to black when it came into contact with Sulphur pollutants that was released from coal.

Publishers then turned to emerald and Paris green dye - which was more long-lasting than Scheele's alternative - and used it in book covers, clothing, candles, wallpaper, and in house paint. 

'I knew about wallpapers that had arsenic pigment and I knew of book illustrations that had arsenic pigment in them, but you don't expect poison to be covering the outside of a book where you're going to hold it to read it,' Melissa Tedone, a conservator at Delaware's Winterthur Museum told CBC Radio.

Researchers kickstarted the Poison Book Project in 2019 when they tested hundreds of covers for heavy metals including lead, arsenic and chromium.

Librarians have removed books from their shelves after discovering the green dye contains quantities of arsenic. Pictured: 'My Own Garden: The Young Gardener's Yearbook' published in 1855 and laced with arsenic at the Leeds Central Library

Red-colored books also contain a harmful mineral called cinnabar, also known as mercury sulfide, which can cause kidney damage and respiratory problems

The red dye containing cinnabar is also found on the inside cover of marbled books created in the 19th Century. Pictured: a marbled book at Museums Victoria contains both lead and mercury

They also found that books embossed with red dye contains cinnabar, a mineral also known as mercury sulfide which ranks high on the Centers for Disease Control and Prevention's toxic substances list.

The dye can be found mixed in the marbled patterns that appear on older book covers or as a single vibrant red that dates back thousands of years and can lead to mercury poisoning which can cause neurological and kidney damage and lead to respiratory problems.

Yellow book covers were also implicated and found to contain traces of lead chromate which is toxic in high quantities.

However, the yellow dye doesn't raise the same level of concern as red or green-dyed books, because it isn't as soluble - making it difficult for people to absorb just by handling the cover.

People who work in libraries or might have arsenic-clad books at home should take steps to protect themselves from the chemical by wearing gloves when handling the book and washing your hands immediately after.

Those who handle the books should also place them in a plastic back to prevent the toxins from flaking off the book, something that prompted Tedone's discovery of the arsenic pigment.  

'We are not aware of any cases of anyone getting seriously ill from handling a book like this,' Tedone told CBC. 

'We just want to make people aware of the potential hazards so that we can avoid any tragedy ever happening from one of these books.' 

READ MORE: Poisonous books laced with ARSENIC found in a Danish university library - and experts warn museum paintings around the world may contain the same poison 

Researchers from Denmark found three rare books poisoned with arsenic. 

Tedone first discovered the arsenic coating while she was repairing a book's spine and boards when the green pigment started flaking off the book.

'It really seemed like the color was in a thick coating that was just on the surface of the book cloth, rather than a dye which would have penetrated the textile fibers of the book cloth and colored the fibers themselves,' she told CBC.

The book cover was tested using an X-ray fluorescence and raman spectroscopy that is used to examine chemical compounds and confirmed the dye contained arsenic. 

'We're sort of following that path of looking at all the toxic components that could be in book cloth,' she told CBC, adding: 'But then we're also trying to document all of the 19th Century mass-produced book bindings that might contain any kind of arsenic in them.'

In the decades after the emerald and Paris dye was discovered, reports surfaced of people dying after coming into extended contact with items coated in the dye.

The reports extended to candles poisoning children at Christmas parties, poisonous green-colored ballgowns poisoning the person wearing it and factory workers convulsing and vomiting green water after applying paint to ornaments. 

Exposure to the tainted dyes has also been linked to Pride and Prejudice author Jane Austen's death and Napoleon Bonaparte's death from stomach cancer.

‘Books traditionally are seen as fairly safe objects,’ said Hayley Webster, the manager of Museums Victoria’s library. 

‘Now I'm feeling like there's a lot more to learn and a lot more that I need to know.’