What is the recommended method for preventing giardiasis through water safety?

Boiling water for one minute is the recommended method for preventing giardiasis through water safety due to the effectiveness of heat in killing the Giardia lamblia parasite. Boiling water raises the temperature to a level that ensures the destruction of pathogens, including cysts of Giardia, which are resistant to many chemical disinfection methods.

While chlorination can effectively kill many harmful microorganisms, Giardia cysts have a higher resistance to chlorine than other pathogens, making chlorination less reliable for preventing this specific infection. Filtering with a cloth does not adequately remove cysts and may merely reduce the number of parasites without eliminating them completely. UV light treatment can be effective but is dependent on proper usage and exposure time, which may not always be guaranteed in emergencies or ad-hoc situations.

Thus, boiling water is a simple, direct, and non-reliant method that can ensure the elimination of Giardia from drinking water, making it a superior option for water safety in the prevention of giardiasis.