Each filter processed 10 gallons, and contaminant levels were compared between filtered and unfiltered samples.
The study focused on six widespread tap water contaminants in the U.S.
Most U.S. tap water meets legal limits, but these limits may not guarantee safety. There’s often a gap between health-protective levels determined by science and government-set limits, influenced by costs and politics.
Over 150 contaminants lack federal limits, and many existing limits are outdated.