[efharisto (OP)]

TRIHALOMETHANES ARE A BY PRODUCT OF CHLORINATION OF WATER. ONE OF THE TRIHALOMETHANES IS COMMONLY KNOWN AS CHLOROFORM. CAN ANYONE TELL ME HOW THESE TRIHALOMETHANES REACT ONCE THEY ARE RELEASED INTO AIR AND/OR SOIL?
FURTHERMORE COULD THE PRESENCE OF CHLOROFORM IN WATER INDICATE THAT THIS WATER IS TREATED WATER [CHLORINATED] OR CAN IT BE FOUND FREELY IN THE ENVIRONMENT?

[lancenti]

From what I understand, chloroform and other trihalomethanes are able to undergo what is called a free radical substitution (FRS) when hit with UV light. In the upper atmosphere, this destroys O₃ or Ozone and turns it into O₂.