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How Janssen came to the rescue of Xi’an’s terracotta army

How Janssen came to the rescue of Xi’an’s terracotta army
No one would ever have expected pharmaceutical knowledge to be useful for archeological conservation. Read what tropical medicine can do for an ancient Chinese army.

Following Belgian Congo’s independence in 1960, Dr. Paul Janssen recruited extensively amongst returning expatriates with scientific profiles: pharmacologists, neurologists, veterinarians, and other specialists. Thus, over time Janssen Pharmaceutica developed expertise in tropical medicine. One of the focus areas were fungi. The expatriate microbiologists developed a huge library of fungi and fungal spores to screen compounds for anti-mycotic activity, leading to the discovery of a number of active agents effective against molds and fungi. Not only did this lead to the development of treatments for fungal infections in patients, but some were also developed as an agrochemical product to prevent fungal decay in grain crops and vegetables.

As this branch of Janssen’s activities was expanding scientifically and medically, Dr. Paul Janssen was also paving the way in China. In 1985, Janssen Pharmaceutica reached an agreement with the Chinese government to build a new manufacturing facility in Xi’an, the capital of Shaanxi province. The eight buildings in the complex totaled 325,000 square feet of manufacturing space and produced medicines for shipment throughout China. As the construction site in Xi’an expanded to make way for the Janssen factory, an army of ancient warriors was emerging from the Chinese soil only twenty-five kilometres away.

In 221 BC, Emperor Qin Shi Huang united seven States to create China’s first empire and established Xi’an as the new capital. Amongst the many things he did in many fields to establish a strong society, he linked numerous existing small defensive walls along the empire’s northern border, a precursor to what became the Great Wall. Another project was the building of his own tomb. Qin Shi Huang surrounded his mausoleum with thousands of terracotta warriors: life-sized reproductions of soldiers, some standing with chrome-plated bronze swords and spears, some kneeling with drawn bows and arrows, and still others driving chariots behind horses made out of clay.

When Dr. Paul Janssen visited the excavation site in the late 1990s - the warriors were not looking very well... The terracotta had weakened due to the warm and humid conditions in the museum. This caused the warriors to be covered with mold. And this is where the story of tropical fungi expertise and Janssen’s terracotta neighbours in China came together.

In 1999, Dr. Paul Janssen returned to Beerse with a few samples of the infected terracotta. Fungus experts in Janssen’s bioresearch laboratory examined these terracotta patients. They identified different mycotic species and used their arsenal of antifungal products to cure the warriors’ infections. Using flowerpots as test objects contaminated with a mixture of the Chinese fungal spores and subjected to environmental conditions close to those at the Xi’an museum, they discovered after twelveweeks that the untreated control pots were covered with fungi, but the pots pretreated with Janssen’s anti-mycotic agents remained fungus-free.

After field tests at the Xi’an site, the scientists prepared water-based solutions of the fungicides and applied them using a simple spray. Janssen provided its specially formulated fungicides to the museum free of charge for a two-year trial period. Under the “Agreement of Protection for the Site of Terracotta Army and Relevant Relics,” Janssen not only provided its custom formulated products, but also trained several of the museum’s scientists in antimicrobial techniques and established a state-of-the-art microbiology laboratory at the museum – the Dr. Paul Janssen Laboratory for Advanced Material Protection.

The original three-year cooperative agreement has since been renewed twice (currently running until 2017). Chinese experts now conduct scientific research with autonomy, and the Museum of the Terracotta Warriors and Horses has become a centre of excellence for research on bio-deterioration of cultural artifacts for the entire People’s Republic of China.