Boiling THM-rich water may boost chemical potency
THMs are a group of more than 60 chemicals, including chloroform — created as by-products when peaty water or water with excessive algae is treated with chlorine to disinfect it. They are considered potentially carcinogenic but the HSE has downplayed the risk, saying such studies are “inconsistent”. However, boiling water with high levels of THMs can actually increase their potency.
In Carraroe, Co Donegal, boil water notices have been issued to up to 4,700 consumers due to the presence of cryptosporidium in the water. However, water in the area also has historically high levels of potentially toxic THMs due to widespread use of chlorination to disinfect the water.
