Final answer:
Despite the U.S. having some of the safest drinking water, contamination from pathogens and chemical pollutants does occur, and over 40,000 U.S. water bodies are impaired. The exact number of Americans exposed to unsafe drinking water over their lifetimes is not clear, but given global statistics and concerns, a significant portion may be at risk.
Step-by-step explanation:
When discussing how many Americans are exposed to unsafe drinking water in their lifetimes, it is important to consider that, although the U.S. has one of the safest drinking water supplies in the world, contamination does occur. Drinking water can become unsafe due to pathogens like Cryptosporidium, E. coli, Hepatitis A, and Giardia intestinalis, as well as chemical pollutants from various sources, leading to impaired water bodies.
More than 40,000 water bodies in the U.S. are considered 'impaired' by the EPA, which indicates they do not meet water quality standards and cannot support a healthy ecosystem. Furthermore, public polls consistently show that Americans are significantly concerned with water pollution, which includes the availability of clean drinking water as one of the top environmental problems. While specific statistics regarding lifetime exposure to unsafe drinking water for Americans are not readily available, the data indicates that a substantial number of people are likely at risk at some point.
In the global context, unsafe drinking water and inadequate sanitation continue to be a significant health crisis, leading to millions of deaths, particularly in developing countries. The presence of intestinal worms, malnutrition, anemia, and stunted growth in children are some of the devastating impacts associated with unsafe water.