In previous columns recommendations for displaying and storing your family treasures include temperature between 68-70 degrees) and relative humidity between 50-55 percent; lights kept off when not needed; fragile items are stored in boxes or drawers with appropriate support; free of insects and air circulation. A good storage environment acts as a preventative measure to reduce the need for more invasive procedures to preserve the items.
A factor of living in the tropics is the prevailing environment causing mold. Mold is the common term used to describe a downy or furry growth on the surface of organic matter, caused by fungi, especially in the presence of dampness and decay. A fungus (plural fungi) may be any of a large number of microorganisms that are parasites feeding on living organisms or dead organic matter.
Fungi are simple-celled organisms that do not need energy from light for growth which bear microscopic spores that are produced in enormous quantities. They are often water repellent and resistant to desiccation (drying out). There are approximately 1.5 million mold species, each requiring different environmental conditions to survive. Mold can produce irregular stains that may permanently damage an object.
Mold is impossible to completely eliminate from any area, as mold spores are in the air at all times. Items made of skin (i.e. shark skin on a pahu), textiles, fibers (lauhala) and paper are particularly susceptible to mold growth.
While most molds that feed on cellulosic materials such as books and manuscripts are only active when the relative humidity climbs above 65-70 percent, temperatures above 72°F also exacerbate mold growth, conditions we have here almost daily! Certain insects feed on fungi and can carry spores onto normally resistant materials. As the insects die, they become the nutrients for a new fungal colony.
This ability to exist on almost any material characterizes mold as a primary agent of deterioration.
Extreme cold, freezing, and heat deactivate spores or spore growth but do not kill them. If temperatures go up after cold, spores can be reactivated and mold will continue to grow. When the spores are in a favorable environment, they will germinate.
Mold can stain wood, textiles and paper, and decrease the strength of their structures, making them more porous and fragile. Fungi may cause loss of protein or starch sizing in paper materials, causing them to absorb water more easily. These growths can result in scattered spots, known as foxing, on paper prints or drawings. Leather is particularly susceptible to mold and can be stained and weakened by it.
When you consider our average temperature and humidity on Kaua’i are seldom within the recommended parameters other precautions can be made; good circulation and maintaining clean, clutter-free storage areas.
Mold prefers humid, still environments so by keeping air moving around items assures the moisture doesn’t settle on them. Also avoid displaying or storing items on floors, windowsills, and metal or cement surfaces and inspect your items regularly.
Repair leaking pipes, gutters and downspouts, cracked windows, problem roofs, deteriorated brick, masonry pointing, or cracked walls. Change air filters regularly, insulate cold water pipes, ventilate crawl spaces if possible, and maintain HVAC systems.
Inspect for signs of visible mold growth or the telltale “musty” smell. If an object shows signs of infestation, seal it in a polyethylene bag or enclose it in polyethylene sheeting to prevent the spread of spores to other objects.
Do not touch the mold, as this will spread the spores. Isolate invested items from other materials, as mold spores travel through the air and can infect “clean” materials. Disposable rubber or plastic gloves and a particle dust mask (two head straps fit more securely) should be worn when handling moldy items.
Deactivation options include air-drying at a temperature between 86°F and 104°F, freeze-drying, exposure to ultraviolet light or sunlight. Thoroughly dry the items and then remove the mold by vacuuming once the mold is dry and powdery. Vacuum the item using a HEPA filter vacuum cleaner that does not exhaust spores back out into the room while continuing to wear protective gear and the clean the shelf or area before replacing the item.
Helen Wong Smith is director of the Kauai Historical Society.