Water for people.pdf - WHO Thailand Digital Repository

B A S I C N E E D S A N D T H E R I G H T T O H E A LT H / 1 1 5Box 5.4: Effect of improved water supply and sanitation on global problem of blindnessTrachoma is an eye infection caused by Chlamydiatrachomatis which can lead to blindness after repeatedreinfections. It spreads easily from one family member toanother by ocular and respiratory secretions. Flies can alsotransmit the infection. WHO estimates that roughly146 million people presently suffer from trachoma andassociated infections, primarily among the poorest ruralcommunities in developing countries. Roughly 6 millionpeople are blind or severely visually disabled because oftrachoma, making it one of the leading causes ofpreventable blindness worldwide. Central to controllingtrachoma is easy access to sufficient quantities of water,facilitating the frequent washing of children’s faces andimproved environmental hygiene.The WHO Global Alliance for the Elimination ofTrachoma by 2020 has adopted the ‘SAFE’ strategy,consisting of four components: Surgery, Antibiotictreatment, promotion of Facial cleanliness and theinitiation of Environmental changes. Recent reviews haveemphasized the importance of the F and E components ofthe ‘SAFE’ strategy, concluding that improved personal andcommunity hygiene has great potential for a sustainablereduction of trachoma transmission. They also concludedthat there is likely to be a long-term beneficial effect of acombination of improved water supplies, provision oflatrines, facial hygiene promotion and control of eyeseekingflies. Trachoma is a just one example of a numberof human eye and skin infections that can be reducedthrough improvements in water supply, sanitation andhygiene promotion.Sources: Prüss and Mariotti, 2000 and Emerson et al., 2000.three. A reduction in the time required to collect water may translatenot only into greater net water availability but also into more time formothers to engage in childcare activities, including feeding andhygiene. Studies by Prost and Négrel (1989) point out that a twentyfoldreduction in time used for water collection resulted in thirty timesmore water used for child hygiene. The impact of such a considerableincrease on diarrhoeal disease is hard to quantify, but it certainly playsa key role in the reduction of trachoma (see box 5.4).Water management practicesManagement decisions on water resources and water services will allpotentially have an impact on human health, yet they are made byactors in many different public sectors as well as in the private sector,often with little awareness of the nature and magnitude of theseimplications. In many countries, institutional arrangements and othermechanisms for intersectoral coordination are rudimentary at best. Asa result, considerable opportunities are lost to protect and promotehealth in the management process. As long as water policies andprogrammes remain fragmented, it will continue to be a challenge toaddress water-associated health issues in a cross-cutting way.The World Water Assessment Programme (WWAP) Secretariattook note of these concerns; as a result, irrigation watermanagement for health, for example, is covered in chapter 8, whileample coverage of urban water supply and sanitation can be foundin chapter 7.For drinking water supply services, water quality management iscritical. A wide range of both chemical and microbial constituents ofdrinking water can cause adverse human health effects. Thedetection of these constituents in both raw water and waterdelivered to consumers is often slow, complex and costly, whichlimits early warning capability and affordability. Reliance on waterquality determination alone is insufficient to protect public health.The most effective and protective means of consistently assuringa supply of acceptably safe drinking water is the application of apreventive ‘quality assurance’ framework. A preventive framework,developed to manage drinking water quality, works in an iterativecycle encompassing assessment of public health concerns, riskassessment, establishing health-based water quality targets and riskmanagement. Feeding into this cycle are the determination ofenvironmental exposure levels and the estimation of whatconstitutes a tolerable risk (Davison et al., 2002).Drinking water quality management may be established througha combination of protection of water sources, control of treatmentprocesses and management of the distribution and handling ofwater. It has five key components:1. water quality targets based on critical evaluation of health concerns;2. system assessment to determine whether the water supply chain(up to the point of consumption) as a whole can deliver water ofa quality that meets the above targets;