Books are sensitive to humidity and heat and their life span can be shortened by exposure to environmental extremes. These factors, as well as exposure to water and prolonged exposure to direct sunlight cause various forms of damage. Contact Circulation (314-935-5420) or Preservation (314-935-4287) immediately if you have a wet book. 

Water-damaged materials are at risk of mold growth while they remain wet. They are also more susceptible to mold outbreaks later on, after they have been dried, if environmental conditions become favorable for growth. 

Be careful of books near open windows or left outside. Direct sunlight over time can fade book covers. If books are extremely cold due to weather conditions, wait until they come to room temperature before opening them up. Cold causes the adhesives to become stiff and brittle -- so opening them too soon or too much can cause damage.

This book actually has dead plant material on some of the pages.

This book was returned to Circulation with this mold damage present. It obviously became wet when borrowed by a patron. Perhaps it was not noticed, and remained wet until mold formed.