The Boston Public Library (BPL) reopened its rare book collection today following ten weeks of painstaking remediation after mold spores were discovered on a medieval text and other documents in September. According to Smithsonian magazine, it’s thought that construction at the library caused the carefully controlled humidity in the department to be not so carefully controlled allowing the mold to grow. The Boston Globe reports that it took a specialized crew of 20 working daily for 10 weeks to clean the 500,000 books and 1 million manuscripts in the collection.

Most of us don’t have a rare book collection that numbers in the millions, but we do have a box of favorite books from our past stored away for a future day. If those books are stored in places where the only climate control is what the weather is that day (places like the garage, the basement or the attic) chances are pretty good that like that medieval text, they may have some mold spores. Or, more likely, fully grown and thriving mold colonies. One of the most disheartening feelings in the world is opening that special box of books and getting a nose full of musty, moldy, sad book smell.

Mold and mildew love nothing better than darkness, dampness and a tasty food source like a book. Once the fungus sets up shop and begins spreading its nasty spores, it doesn’t discriminate between outdated textbooks and beloved children’s books. Mold is an equal opportunity invader.

Unless the books are rare, valuable or irreplaceable, it’s best to dispose of moldy books. Not donate, dispose. It’s painful to do, but really it’s the only choice. It’s not worth the risk that by donating you may send the book somewhere it can spread mold to someone else’s collection or even worse, send it to the home of someone sensitive to mold like a person with asthma.

Moldy and musty books can be cleaned, but it’s a time intensive process. Books that have great sentimental or financial value are likely best cleaned by a trained conservation professional. Books that are not quite so pedigreed, but are worth the sweat equity to try and save can be worked on at home. There is a lot of information about how to do this from true book lovers and experts available on the internet–a simple search will give you lots of methods to try.  We are certainly not experts, but we’ve found that sunshine, fresh air and a gentle wiping can go a long way towards freshening a sentimental favorite.

If your book has rusty reddish spots, you might have foxing instead of mold. Foxing happens when the minerals in the paper change over time. Foxing isn’t pretty, but it also isn’t terrible and invasive. Mold can generally be distinguished from foxing because it comes in a dingy rainbow of colors: blues, blacks, grays, greens, yellows.

Disheartening though it may be to find that your beloved copy of Little Women, Nancy Drew Secret of the Old Oak or To Kill a Mockingbird has been feasted upon by fungus, the good news is that for many titles, another copy can be found through a reputable online seller.