Biblical Text-Writing May Have Poisoned Monks

June 27, 2008 -- Medieval bones from six different Danish cemeteries reveal that monks who wrote Biblical texts and other religious materials may have been exposed to toxic mercury, which was used to formulate just one of their ink colors: red.

The study, which will be published in the August issue of the Journal of Archaeological Science, also describes a previously undocumented disease, called FOS, which was like leprosy and caused skull lesions. Additionally, the researchers found that mercury-containing medicine had been administered to 79 percent of the interred individuals with leprosy and 35 percent with syphilis.

Since the monks, who were buried in the cloister walk of the Cistercian Abbey at Øm, did not have these diseases but contained mercury in their bones, scientists believe the monks were either contaminated while preparing and administering medicines, or while writing the artistic letters of incunabula, or pre-1500 A.D. books.

Kaare Lund Rasmussen, a University of Southern Denmark scientist at the Institute of Physics and Chemistry, suspects that ink used in the abbey's scriptorium was the culprit.

He told Discovery News "it is very human to lick the brush, if one wants to make a fine line."

Even today "one should really not touch, or much less rub, the parchment pages of an incunabulum," Lund Rasmussen said, adding that mercury "was used in the first place because cinnabar (a type of mercury) has this bright red, beautiful color."

It is also known that metallic liquid mercury was given in vapor form to diseased patients. So if the monks "were just a little careless, they would be exposed this way, however, they might also be exposed during the preparation of the medicine."

For the study, Lund Rasmussen and his team drilled bone samples from the buried individuals, some of which were also friars buried in the cloister walk of the Franciscan Friary in Svendborg. Unlike the Øm monks, the friars showed no signs of mercury poisoning.