Neither the clarity nor location of a water source necessarily determines whether water is safe to drink, but the invisible parasites that come from fecal matter can be deadly. According the the World Health Organization (WHO), human waste is the greatest cause of water contamination that leads to death.
WHO reports that the greatest killer resulting from water contamination is Diarrhea, which kills 842,000 people annually. Most of those impacted are children who have yet to develop their immune systems.
One of every four people in the world drinks water that is occasionally contaminated and about 663 million people suffer from a lack of access to any clean drinking water. However, over the past two decades, at least 2.6 million people have gained access to clean water and at least 90% of the world has access to cleaner water sources; the WHO suggests that greater monitoring of these sources is necessary nevertheless to ensure their reliability to deliver clean, safe drinking water.
Read full story at: NPR