Gruinard island is an example of a negative effect on connections to an island. In the midst of world war 2 the uk goverment conducted research into biological bombs, testing the results on a remote island off the coast of scotland. The resulting contamination lasted for 50 years before being removed, in which time nothing could survive on the island.
Strangely now the island has a heightened interest and increased connections with news reporters visiting. Before the incident there was really no reason to visit the island but now there is a false challenge to go there.