Four years after the United Nations announced that it had halved the number of people without access to cleaner water, a new analysis shows that getting to that water is still a major hardship for much of sub-Saharan Africa.
More than two-thirds of that region's population still must leave home to collect water and haul it as far as two football fields - backbreaking work that in 24 countries falls mostly on women and children carrying buckets as heavy as 18kg.
The result is "fatigue, musculoskeletal damage and early degenerative bone and soft tissue damage" for individuals who often are already frail, according to the analysis, which was published in the journal PLOS One.
In households that spent 30 minutes to collect water from a well or some other protected source, the water bearers included 13.5 million women and 3.4 million children living in countries such as Niger, Ethiopia, Cameroon, Burundi, South Africa, Liberia and the Ivory Coast.
Girls vastly outnumbered boys, 62 per cent to 38 per cent, the analysis found. Adult women tasked with water collection ranged from about 45 per cent in Liberia to 90 per cent in the Ivory Coast.
Even in a more developed country such as South Africa, more than half of water bearers were adult women. Nearly a third were girls.