TIRUVARUR: As a court-appointed ASI team painstakingly scrutinises the antiquity of stored in
safety vaults in temples across Tamil Nadu, some disturbing facts have come to light. The team
found that a significant percentage of the 1,100 idols screened so far in the Tiruvarur icon centre,
which houses at least 4,380 antiques, suffer from what’s called bronze disease. Some experts refer
to it as , the chloride corrosion of idols that, they say, is incurable and sometimes contagious.
With few or no protocols in place for conservation, hundreds of idols have been crammed into icon
centres without proper light and in uncontrolled environment. The ongoing elaborate exercise is
equivalent to a detailed audit, probably the first such being carried out in the state. While the expert
team, comprising ASI officials and idol experts, has a long way to go as it visits one icon centre after
another to check if the idols are original Chola or Pallava-era antiques, the scant regard for their
proper preservation in vaults is proving to be a big challenge.
Dr B Venkatraman, director, health safety and environment group, Indira Gandhi Centre For Atomic
Research (IGCAR), told TOI that bronze disease was detected among the 900-odd idols that were
sent to him for analysis
Chloride corrosion can affect artefact
On ASI’s direction, IGCAR has taken up artistic evaluation and historical documentation along with
X-ray fluorescence analysis to ascertain the chemical composition of the idols, he said. “Some of
these problems are inevitable since the icons are made of metal, which, unlike stone, is a corrosive
material,” said Bengalurubased Prof Sharada Srinivasan, who is a member of the Advisory Board of
the Institute of Archaeometallurgical Studies, London. “Copper-bronze alloys in particular tend to be
susceptible to bronze disease due to possible contamination by chloride salts,” she said. This results
in chloride corrosion whereby initially light green spots form and if unchecked, it can be irreversible
and affect the entire artefact.