Estimating the impact of unsafe water,sanitation and hygiene on the global burden of disease: evolving and alternative methods

The 2010 global burden of disease (GBD) study represents the latest effort to estimate the global burden of disease and injuries and the associated risk factors. Like previous GBD studies, this latest iteration reflects a continuing evolution in methods, scope and evidence base. Since the first GBD Study in 1990, the burden of diarrhoeal disease and the burden attributable to inadequate water and sanitation have fallen dramatically. While this is consistent with trends in communicable disease and child mortality, the change in attributable risk is also due to new interpretations of the epidemiological evidence from studies of interventions to improve water quality. To provide context for a series of companion papers proposing alternative assumptions and methods concerning the disease burden and risks from inadequate water, sanitation and hygiene, we summarise evolving methods over previous GBD studies. We also describe an alternative approach using population intervention modelling. We conclude by emphasising the important role of GBD studies and the need to ensure that policy on interventions such as water and sanitation be grounded on methods that are transparent, peer‐reviewed and widely accepted.     

Millennium development goals and the water target: details, definitions and debate

One of the primary targets of MDG 7, dealing with issues of environmental sustainability, is to halve by 2015 (from 1990 levels) the proportion of the population without sustainable access to safe drinking water and basic sanitation. It is undoubtedly difficult to summarise a complex target such as access to water or safety of water source in a single quantifiable indicator. However, in our opinion, the indicators used to estimate how much of the population has 'access' to 'safe' drinking water leave out some important elements that should be taken into account when determining whether the goals have been met. In addition, the authors propose a modification to Bradley's classification of water-related illness to include a category for waterborne diseases of a non-infectious aetiology.