A study conducted by researchers at the Université Laval in Quebec found that using an activated-carbon water filtration system on tap water significantly reduced some types of contaminants that were not removed in other ways, such as boiling the water.

Specifically, haolacetic acids or HAAs, which are by-products of disinfecting the water with chlorine, were not eliminated by boiling the water or storing it in the refrigerator. However, use of a carbon-activated home water filtration unit reduced the concentration of HAAs by 66%.

HAAs do not alter the smell or taste of tap water but are suspected of increasing the risks of certain types of cancer.

Using an activated-carbon filtering pitcher significantly reduces chemicals in tap water