Artifact Conservation and Historical Archaeology at Historic St. Mary's City |
   The Preventive Care Preventive conservation involves controlling certain environmental variables that can potentially alter the structure and condition of archaeological collections. This section discusses effective methods of preventive care practiced by Historic St. Mary’s City. Common environmental variables that may be detrimental to the preservation of artifacts are fluctuations in temperature and relative humidity, destructive pests, ultraviolet radiation, and dust particles. Acidic oils found on the skin can degrade the integrity of artifacts as well. The utilization of a hygrothermograph enables the museum staff to closely monitor and, if necessary, alter the environment in order to protect the objects. This tool accurately records the air temperature and relative humidity (RH) of areas that house artifacts. The acceptable temperature and RH levels for spaces that store or exhibit artifacts are 68-70˚F and 45-50% RH. Altering or controlling the environment is efficiently executed with an HVAC system. Another preventive practice involves IPM activities. These techniques include storing certain organic materials in freezers, setting and monitoring insect and rodent traps, vacuuming regularly, and storing food in airtight containers outside of collections areas. These methods take the place of harmful chemical-based pesticides, which can also be hazardous to humans. Ultraviolet (UV) radiation tends to fade the pigments found in artifacts such as archaeological textiles and leather. The amount of radiation that may come into contact with vulnerable objects can be decreased by the installation of UV-absorbing filters on window panes inside collections spaces or by utilizing dark curtains or blinds to prevent overexposure. Storing collections in acid-free boxes or creating archival storage mounts with lids works to further protect objects from ultraviolet radiation. Dust can attract airborne pollutants and moisture, which can play a major role in the deterioration of artifacts. Vacuuming collections areas routinely, storing artifacts in enclosed cabinets, and implementing the use of dust covers will decrease the presence of this abrasive material. When mounting artifacts, it is important to wear cloth or nitrile gloves. These items protect objects from the acidic oils found on the skin as they can leave behind evidence of improper handling. Permanent fingerprints etched into the surface of a metal artifact are an example of the damage an object can sustain when gloves are not worn. These preventive methods practiced at Historic St. Mary’s City significantly reduce the risk of environmental damage to artifacts and aid in the preservation of archaeological collections. |
|
|||||||||
