This is mainly due to the fast growth of the region’s urban population, which has more than doubled since 1950, and the issues faced by cities in developing the adequate infrastructure to keep up with the escalating water and sanitation needs. This inequality of access between rural and urban areas varies among sub-regions, as shown in Figures 9.3 and 9.4. Within cities, it is the poor urban populations that tend to be left behind. Women and girls are traditionally responsible for domestic water supply and sanitation in many countries, whilst at the same time being particularly affected by the lack of availability of sanitation services in terms of health and safety (see Section 2.2).