Half the hospital beds in developing countries are filled with people suffering from diseases caused by poor water, sanitation and hygiene.
(UNDP Human Development Report, 2006 http://hdr.undp.org/en/media/HDR06-complete.pdf  page 45)

Hygienic practices such as washing hands with soap can reduce the risk of diarrhoea by 50%
(Curtis and Cairncross, 2003; Luby, et al. 2005)

Hygiene promotion is the most cost effective health intervention according to the World Bank.
(Saving lives, WaterAid, 2012)

Just £15 can provide one person with access to safe water.
(WASHCost and WaterAid, 2014)

Lack of water, sanitation and hygiene costs Sub-Saharan African countries more in lost GDP than the entire continent gets in development aid.
(Using percentage estimate from UNDP: Human Development Report, 2006)