In emergencies, which method is effective for disinfecting small quantities of water?

Tincture of iodine is an effective method for disinfecting small quantities of water during emergencies because it is a strong antiseptic that can kill a wide variety of pathogens, including bacteria, viruses, and some protozoa. The iodine in the tincture acts by disrupting the proteins and nucleic acids of microorganisms, rendering them inactive. For water purification, adding a specified amount of tincture to the water allows it to effectively reduce the risk of waterborne illness when proper boiling or filtration methods are not available.

In contrast, while aluminum salts can be used for water treatment in larger systems as coagulants and flocculants, they are not a reliable method for immediate disinfection of small water volumes. Salt tablets may enhance flavor or assist with balancing electrolytes but do not provide disinfection properties. Direct exposure to sunlight can kill some microorganisms through ultraviolet radiation, but the effectiveness depends heavily on water turbidity and exposure time, making it less reliable than tincture of iodine in emergency scenarios.