Global Issues in Water, Sanitation, and HealthGlobal Issues in Water, Sanitation, and Health As the human population growstripling in the past century while, simultaneously, quadrupling its demand for waterEarth's finite freshwater supplies are increasingly strained, and also increasingly contaminated by domestic, agricultural, and industrial wastes. Today, approximately one third of the world's population lives in areas with scarce water resources. Nearly one billion people currently lack access