Water and nonwater-related challenges of achieving global sanitation coverage.

Improved sanitation is considered equally important for public health as is access to improved drinking water. However, the world has been slower to meet the challenge of sanitation provision for the world's poor. We analyze previously cited barriers to sanitation coverage including inadequate investment poor or nonexistent policies, governance, too few resources, gender disparities, and water availability. Analysis includes investigation of correlation between indicators of the mentioned barriers and sanitation coverage, correlations among the indicators themselves, and a geospatial assessment of the potential impacts of sanitation technology on global water resources under six scenarios of sanitation technology choice. The challenges studied were found to be significant barriers to sanitation coverage, but water availability was not a primary obstacle at a global scale. Analysis at a 0.5 degrees grid scale shows, however, that water availability is an important barrier to as many as 46 million people, depending on the sanitation technology selected. The majority of these people are urban dwellers in countries where water quality is already poor and may be further degraded by sewering vast populations. Water quality is especially important because this vulnerable population primarily resides in locations that depend on environmental income associated with fish consumption.