Takamatsuzuka tomb in Asukamura, Nara Prefecture, has seen extensive mold growth since construction workers dispatched by the Cultural Affairs Agency worked in its stone chamber without wearing sterilized protective clothing in 2001, it has been revealed. The mold initially grew on the chamber's exterior and spread to its interior, where wall paintings, a national treasure, are located. The agency is likely to be criticized for its sloppy management of the early eighth-century tomb, as a worker was also discovered to have damaged one of its murals.

According to the agency's inspection diary, the work was performed from Feb. 13 to March 2, 2001, to prevent dirt from falling from a part of the chamber's ceiling connected to an air-conditioning unit. At the time, the construction workers wore no protective clothing. Immediately after the work, a large quantity of mold was found on the chamber's exterior.

In December 2001, black mold was found near the bottom of a mural depicting a group of women on the east wall and other parts of the chamber. As the mold continued to spread, the agency decided in June to dismantle the chamber to restore the wall paintings.

The agency's manual on preserving and repairing the chamber interior requires that cameras, interior lamps and other tools be sterilized with alcohol when they are brought into the chamber, and that workers wear protective clothing at the time of regular inspections and mural preservation work.

In 2001, however, the workers wore only regular uniforms as they needed to frequently carry tools in and out of the tomb.

According to the agency's Fine Arts Division, there are several causes, besides the lack of protective gear, for the mold that grew following the 2001 work, including warmer temperatures and insects.

Prof. Akio Donohashi of Kobe University, an art historian who serves as a member of the tomb's permanent preservation planning committee, said: "Although it's obvious that mold growing outside the chamber damaged the murals, the agency hasn't been forthcoming with its information. I can't imagine what the committee really discussed. I believe human error has led to the decision to dismantle the chamber."

Residents in Asukamura have had similar harsh words for the agency.

Takeshi Seki, 71, chairman of an association promoting the town's local history and relics, said: "The agency acted negligently with a national treasure. It's definitely a careless error. They have yet to give us any information, and more scandals likely will surface in the future."

In March 2003, the agency convened an emergency committee to discuss preserving the tomb.

It told the committee a large quantity of mold had grown on the chamber's exterior due to the lack of antimold measures at the time of construction work outside the chamber.

The committee initially discussed ways to prevent the mold, believing that water seeping into the chamber through tree roots had been the main culprit.

After microbiologists later theorized that warmer temperatures in the chamber were responsible for the growth, the committee took steps to cool the chamber, but it did not solve the problem.

It was also recently learned that a small piece of a mural that fell off in a January 2002 accident has not been recovered.

At the time, the agency gave up on restoring the damaged part of the mural. Instead, workers made a makeshift patch for the mural by mixing sterilized soil from outside the chamber with purified water and applying it to the damaged area.