Exposure levels were selected according to theavailability of exposure data and corresponding expo-sure-risk information (Wolf et al. 2013, 2014) andincluded the following: (i) using an unimproved watersource; (ii) using an improved water source other thanpiped to premises; (iii) using basic piped water on pre-mises (improved source); and (iv) using a water filter orboiling water in the household (on water from an unim-proved or improved source).