Water may cover the globe, but the world’s water resources are limited relative to human demand, causing what the United Nations and others have defined as a global water crisis. According to a UNESCO study, two million tons of wastewater are dumped into the world’s rivers and lakes every day. Severe overuse and clearance of ecologically important forests, intensive agriculture, expanding urban infrastructures and increasing tourism are having an enormous impact on the natural water balance and existing water resources. More than half of the world’s major rivers are polluted or are running dry. Things are not better for many lakes and wetlands.
Inadequate access to safe drinking water impacts about 900 million people, and inadequate access to water for sanitation and waste disposal affects approximately 2.5 billion people. Waterborne diseases and the absence of sanitary domestic water are one of the leading causes of death worldwide. For children under age five, waterborne diseases are the leading cause of death. At any given time, patients suffering from waterborne diseases occupy half of the world’s hospital beds. According to the World Bank, 88 percent of all diseases are caused by unsafe drinking water, inadequate sanitation and poor hygiene.
And according to the World Health Organization (WHO), contaminated water accounts for 80% of all diseases contracted during travel. The most common health risk on trips is the infection by pathogens such as bacteria, viruses and protozoa contained in drinking water. The primary source of contamination is human or animal waste that has entered the water along different paths. Such contaminated water may rapidly lead to infections. According to the European Union drinking water directive 98/83/EC, even water used for showering, laundry and dishwashing must be of drinking water grade.