Claims that the 2,000-year-old terracotta army in Xi'an is in danger of disintegrating were denied by museum officials yesterday.

"The preservation work in the museum is done in a proper way. Any scaremongering about the relics without any scientific foundation is ill-intentioned," Wu Yongqi, director of the Museum of the Qin Terracotta Warriors and Horses Museum, told China Daily.

According to the South China Morning Post on June 27, the head of a team researching the effects of air pollution at the site said it was time to take action to save the relics.

Cao Junji, also executive director of the aerosol and environment division at the Chinese Academy of Sciences' Institute of Earth Environment, said that, if nothing was done now, in 100 years the warriors may have corroded to such an extent that the pits would look like a coal mine.

He said the damage caused by corrosion would be minor at first, but larger features like noses could shrink as the surface is worn, reducing the figures' cultural value as attributes that indicate rank also disappear.

Cao's project, costing 2 million yuan (US$240,000) and involving a number of experts from home and abroad, focuses on air pollution and is to start in September and be completed in 2007.

"We are carrying out the research project as a precaution, not to deal with existing problems," said Wu.

Zhao Kun, director of the museum's Protection Department, said the statues can "resist weathering very well, and since they were unearthed in 1974, they have been housed by special halls with proper protection facilities and measures, so daily wind, sunlight, rain and snow can do nothing to them."

The museum has made efforts to improve its surroundings by planting more trees and grass and limiting commercial activities, according to Zhang Zhijun, Zhao's deputy.

Cao considered becoming involved in some sort of research after visiting the museum in 2002 with his friend Lee Shun-cheng, an expert on indoor air pollution from Hong Kong Polytechnic University.

In May last year he started his search for funding and partners, and this March saw the establishment of the project, a collaboration between the Nevada-based Desert Research Institute, the Chinese Academy of Sciences, the museum and the Polytechnic University.

Air samples will be sent to laboratories in Hong Kong, Nevada and Xi'an to identify the key components, and fragments of the warriors will be sent to the Polytechnic University for analysis.

Cao said the team could only delay the ageing process by targeting the main pollutants and finding ways to reduce them.

The Qin Dynasty (221-206 BC) warriors were discovered in 1974 in Lintong, an eastern district of Xi'an, the capital of Shaanxi Province. They were created to guard the tomb of Emperor Shihuang.

Located 1 kilometer east of the emperor's tomb, more than 7,000 clay warriors and 500 horses were found in three burial pits, which are now all protected under steel and concrete halls, said Wu.

(China Daily July 8, 2005)