We often refer to water as “the stuff of life.” Without water, our cells would shrivel and die, our brain function would be progressively impaired, and we would eventually find it impossible to expel harmful toxins. The same applies to the world around us – the “global skin” in which we live. Without clean water and sanitation, the network of systems which support human life would gradually grind to a halt. Agriculture would become unsustainable, extreme poverty and hunger would flourish, and without sanitation, disease would breed rapidly.

For nineteenth century England, this was daily life, until the “sanitary revolution,” led by Edwin Chadwick and others brought piped water to people’s homes and sewers rinsed by water. It signalled the end for cesspits, privies, and cholera epidemics, and laid the foundations for the cleaner, healthier and longer life which we enjoy today.

In developing countries, however, it remains reality. 884 million people lack clean water and 40% of the world’s population cannot access a safe toilet. Over half of all hospital beds in sub-Saharan Africa are occupied by patients with sanitation- and water-related diseases. 4000 children die from these diseases every day – the biggest killer of children, accounting for five times more deaths than HIV/AIDS and twice as many as malaria.

The political will and the money needed to address this crisis have not been forthcoming. The BMJ recently noted that, of all the Millennium Development Goals (MDGs), sanitation is the most off track. Currently, the 2015 goal to halve the number of people without access to a safe toilet will not be achieved until the 23rd century in sub-Saharan Africa.

The recent UN Summit on the MDGs produced several strategies to increase progress, but conceded that there will be a $26 billion funding gap in 2011 to meet the health MDG targets in the poorest 49 countries. Unless that is closed, including extra funding for sanitation and water, many commitments made at the summit will be meaningless.

In the meantime, for developing nations, when there is no clean water available, the only option is to start walking and find some. To do this, children and parents in developing countries walk an average distance of six kilometres per day for water which is usually unclean, resulting in more disease and very little hope of returning to school or work. This costs poor countries around 5% of their Gross Domestic Product each year.

World Water Day in March 2011 provides an opportunity to send a powerful message to politicians and world leaders. “The World Walks For Water” will see thousands of people all over the world walk 6km to demand political change. End Water Poverty – the international campaign of which the BMA is a member – will be amongst those co-ordinating this mass global call for action. Our message to governments is: you’ve talked the talk for water and sanitation, you must now walk the walk and put promises into action.

For more information: www.worldwalksforwater.org/

Martin Carroll is deputy head of the international department, British Medical Association.