Material collections are treasures troves of historical, cultural, and scientific information, providing invaluable insights into our past. However, they are vulnerable to a range of environmental threats that can significantly impact their longevity. Understanding and mitigating these threats is essential for ensuring the preservation of these precious materials. This post explores the key environmental factors—light, heat, pests, humidity, and more—that affect archival collections and offers strategies for their care.
Light
Impact: Light, particularly ultraviolet (UV) light, can cause severe damage to archival materials. Prolonged exposure can lead to fading, discoloration, and deterioration of paper, photographs, textiles, and artworks.
Mitigation:
Use UV-filtering film on windows and light fixtures.
Store sensitive materials in dark, enclosed spaces.
Limit the duration and intensity of light exposure during display and handling.
Employ LED lights, which emit less UV radiation.
Heat
Impact: High temperatures accelerate the chemical reactions that cause deterioration. Heat can cause warping, melting, and brittleness in materials like paper, film, and textiles.
Mitigation:
Maintain a stable, cool temperature in storage areas, ideally between 65-70°F (18-21°C).
Avoid placing collections near heat sources like radiators, sunlight, or electronic equipment.
Use climate control systems to monitor and regulate temperature.
Humidity
Impact: Fluctuating or high humidity levels can lead to mold growth, warping, and weakening of materials. Low humidity can cause brittleness and cracking.
Mitigation:
Keep relative humidity between 30-50%, with minimal fluctuations.
Use dehumidifiers or humidifiers as needed to maintain stable levels.
Ensure proper ventilation to prevent condensation and mold growth.
Pests
Impact: Insects, rodents, and other pests can cause significant damage to archival materials. They may chew through paper, textiles, and bindings, leaving irreparable harm.
Mitigation:
Implement an Integrated Pest Management (IPM) plan to monitor and control pests.
Store materials in pest-proof containers.
Keep storage areas clean and free from food and drink.
Regularly inspect and clean the collections and storage spaces.
Pollution and Contaminants
Impact: Airborne pollutants such as dust, dirt, and chemical pollutants can cause abrasion, staining, and chemical reactions that degrade materials.
Mitigation:
Use air filtration systems to reduce airborne particles.
Store items in archival-quality, acid-free boxes and folders.
Handle materials with clean hands or gloves to prevent the transfer of oils and dirt.
Handling and Storage
Impact: Improper handling and storage can cause physical damage, such as tears, folds, and deformations. Overcrowding and poor shelving can exacerbate these issues.
Mitigation:
Train staff and users on proper handling techniques.
Use supports and cradles when handling fragile items.
Store materials in appropriate, supportive containers.
Avoid overcrowding shelves and provide adequate support for large or heavy items.
Material-Specific Considerations
Paper and Books: Keep in cool, dry conditions, and handle with clean hands. Use supports for large volumes.
Photographs: Store in acid-free enclosures and avoid prolonged exposure to light. Handle by the edges.
Textiles: Store flat or rolled, and avoid folding. Use acid-free tissue for padding.
Digital Media: Maintain stable temperatures and humidity, and regularly back up data.
The longevity of archival collections depends on our commitment to creating and maintaining a stable and protective environment. By understanding the threats posed by light, heat, humidity, pests, and pollutants, and by implementing thoughtful mitigation strategies, we can ensure that these valuable materials are preserved for future generations. Investing in proper collections care today safeguards the rich tapestry of our shared history for tomorrow.