THMs are chemicals that occur in drinking water as a byproduct of water chlorination. They are highly carcinogenic and can affect nervous system, kidney, and liver functioning.

Trihalomethanes. A byproduct of chlorinated water that contain natural organics. THMs are linked to several types of cancer.

Trihalomethanes are carcinogens that are by-products of the water disinfection process. They are formed when organic compounds found in water come into contact with chlorine used for disinfection during water treatment.