Answer:
Iodine , caesium , strontium ,Plutonium
Step-by-step explanation:
The isotopes of four main elements which include Iodine , caesium , strontium ,Plutonium contributed mainly to contamination in the Chernobyl accident which involved the release of harmful radioactive radiation into the environment.
The accident occurred in 1986 at Chernobyl , Ukraine as a result of errors made in the design of the reactor and inexperienced hands handling it.
This led to hundreds of death and negative effects on living and the environment around the area.