You might not think of water as a source of toxins, but tap water can in fact contain up to 315 pollutants, including arsenic (a heavy metal) and pesticides, according to a 2009 analysis by the Environmental Working Group. And bottled water can contain the same contaminants as tap. Fortunately, there's an easy fix: filter your tap water. Look for a filter for your sink, a pitcher filter or even one in a water bottle. Just make sure it’s certified by the Water Quality Association (wqa.org) or NSF International (nsf.org) to screen out pesticides from farms and golf courses that can leach into well water. In most cases, a $15-20 PUR or Brita pitcher filter will do the trick.