Earth Day can be tied to Science Standards related to Recycling, Pollution and Humans effect on the planet in almost every grade level.
Here are directions for an interactive Earth Day book from http://drjean.org Download EarthBook
More EarthDay activities: Download Earth Day Activities
Earth Day Dominoes: Download Earth Day Dominoes
A number of Boardmaker activities can be downloaded free from www.adaptedlearning.com = search for "Earth Day"
Recycle Bingo: You must have Boardmaker for these activities: