8. And the second angel sounded, and as it were a great mountain burning with fire was cast into the sea: and the third part of the sea became blood;
9. And the third part of the creatures which were in the sea, and had life, died; and the third part of the ships were destroyed.
This is the second trumpeting angel, with the great mountain cast into the sea. 1/3 rd part is numerology for saying that God does not allow the total.
10. And the third angel sounded, and there fell a great star from heaven, burning as it were a lamp, and it fell upon the third part of the rivers, and upon the fountains of waters;
11. And the name of the star is called Wormwood: and the third part of the waters became wormwood; and many men died of the waters, because they were made bitter.
The waters are made bitter, or in other words, poisonous. This could refer to a disease spread in the water or radiation poisoning or literally bitter, meaning the pH balance is somehow raised beyond tolerable levels.
People have also argued back and forth whether the word Chernobyl translates to wormwood. The best truth I’ve been able to find is that it does indeed translate, however the scope of the Chernobyl disaster does not measure up to what is described in these two verses.
Are the references to the great mountain burning with fire and the great star from heaven the same event? Perhaps the first four all happen at the same time.