More than 2 billion people around the world lack access to safe drinking water, and very little progress has been made solving the problem. One of the issues is that while there are ways that householders can make their water potable, the effort or time required is a hindrance. Associate energy and resources professor Isha Ray, co-director of the Berkeley Water Center, points out that in areas where people are poor and already overworked, the extra steps required to clean water properly can be daunting. Expressing doubt that she could do any better in the same circumstances, she says: "One thing we know from the social sciences is people are not all the time driven only and exclusively by health considerations. ... Every single person I know has a gym membership they don't use, including myself," so it's not realistic to expect a person with fewer resources and more daily chores to take on additional water-treatment jobs. Carrying and treating water can be a "painful chore that has to be repeated every day," she says, and it's one that's typically left to women. "And that means her body is acting as infrastructure, covering for a piece of pipe."