ScienceDirect, the platform Elsevier uses for its online journal articles, has added new features. They are partnering with NextBio to provide text mining of ScienceDirect and some free web resources. These services are provided for articles published after 1995 and dealing generally with biomedical topics.
Look for a box to the right of the article abstract titled Relevant Terms from this Article. Following the links will lead you to data correlations and links to more literature. You may not see these extra features for articles on environmental issues.