Dear Donia,
How do I save documents that smell like mildew?
Q. Dear Donia,
A. Dear Janine,
This is a great question, and there are a couple of ways you can go about isolating the smell so it doesn't spread. One option is to get some MicroChamber folders from Conservation Resources. The paper of the folders absorbs odors and traps them within the paper. By storing your documents in these folders, you can prevent the odor from spreading and, over time, reduce the odor of the documents themselves.
Another option is to, where possible, scan the documents and keep them either digitally or print out new copies. This would help decrease the volume of materials that smell.
Finally, if you have sunny day with no wind, you could put small batches of documents out in the sun for a few hours at a time. The UV light will help reduce the smell but it won't get rid of it completely. Be very careful where you put things out and maybe put on small weights so things don't fly away. Don't put under trees or other perches to reduce the risk of bird droppings.
I hope this gives you enough information to decide what is best for you.