It really depends on how large the infestation is, and how long it has been going on.
Damage to paper products from silverfish is caused by their direct
feeding on the materials. The feeding of silverfish results in
irregular feeding areas that exhibit characteristic "thin spots"
Silverfish do not have strong chewing mouth parts and
therefore tend to sit on the surface of the paper and gradually abrade
the surface. In some areas of the damage, the feeding will result in
irregular holes in the paper. In other areas, however, the feeding
will not break entirely through the paper and will result in thin
spots or simply the removal of the printed word.
When silverfish feed on printed materials, they often leave a fine,
pelletized frass (excrement) which is black and resembles a miniature
mouse dropping. Under magnification, this residue is fairly easily
distinguished as individual pellets or droppings. This material
accumulates under items or may be scattered randomly over surfaces in
darkened areas. It may also be found on the interior of acid-free
storage boxes. Large amounts of frass may be found in attics insulated
with cellulose insulation (ground up newsprint).
They prefer moist, dark environments, so ensuring that they don't have that kind of environment to thrive in will go a long way to ensuring the safety of the books and other materials. This article speaks mainly of silverfish in houses, not libraries, but the advice holds.
Silverfish are usually introduced into houses from an outside source.
Prevention of silverfish infestations should begin with sanitation.
Vacuum cracks and crevices to remove dust and lint. Keep bookcases
clean by vacuuming and shaking out books. Don’t allow piles of old
papers and magazines to accumulate. Check old books before bringing
them into the house. Store starched linens in sealed plastic bags.
Seal cracks and crevices with caulking compound to reduce the number
of hiding places. Make the environment less attractive by reducing the
humidity with a dehumidifier. Anhydrous calcium carbonate, a
dehydrating agent, is effective in removing moisture from the air in
closets and other small spaces.
There are also chemical solutions to silverfish problems, but those can also harm the books and other materials - these solutions are best left to people with more expertise in these things, especially where a library collection is concerned.
