Assessment of Potential Damage Factor: A Case Study of St. Paul’s Cathedral,Kolkata

Abstract

Damaging factors such as airborne microorganisms, relative humidity, ventilation, temperature and air pollutants are the major concerns of the tropical climate of Kolkata, India where our study site, 172-year-old St. Paul’s Cathedral is located. In this context, the aim was to develop an equation to assess the management priority and which factors would be more responsible for potentially damaging the heritage building. The temperature varied from 28°C to 31°C, relative humidity was recorded 72% over a period of 14 days in the prayer hall whereas almost constant temperature (27°C) and relative humidity (55%) were recorded in crypt. Air movement was recorded 0.5–3 m s⁻¹ in both crypt and prayer hall. Sulphur dioxide and oxide of nitrogen concentration were lower than the standard mentioned by the Central Pollution Control Board, India. The fungal load was lower inside the crypt (237 CFU m⁻³) than in the prayer hall (793 CFU m⁻³). Calculated potential damage for prayer hall and crypt was found to be 48.75% and 37.08%, respectively. Results revealed that microbial load and relative humidity were the potent factors for damage to the building. Continuous air movement, that is, ventilation and building design here played significant roles. The Heritage Conservation Committee can use the data for better management.