Around 160,000 residents of Murcia have been advised not to drink tap water, after the regional health authority discovered higher than permitted levels of trihalomethanes.
The use of chlorine to disinfect water for the purpose of drinking produces low levels of various disinfection by-products with the trihalomethanes and haloacetic acids being the most common. These substances are by-products of water disinfection that are formed when chlorine is used and there has been an increase generated as a result of organic matter levels in the water supply during the heavy rains last month.
The trihalomethanes and haloacetic acids have demonstrated carcinogenic activity in laboratory animals. Some studies have suggested that an increase in exposure can result in a small increase in the risk of bladder and colorectal cancers. Other investigations have found that chlorination by-products may be linked to heart, lung, kidney, liver, and central nervous system damage.
The water supply which has become polluted serves 49 municipalities in the provinces of Murcia, Alicante and Albacete, after the problems were identified in the Sierra de la Espada water treatment plant.
Residents in Cieza, Alguazas, Abarán, Las Torres de Cotillas, Abanilla, Blanca and Molina de Segura have been alerted by the regional health authorities that it is not recommended to drink tap water at the moment.
The problem does not affect the use of water for cooking or cleaning and is the same as a recent problem in the town of Fortuna, with 10,000 inhabitants, which was normalized this week.