Final answer:
Surface water, particularly in regions with poor sanitation, is commonly contaminated by parasites from fecal matter, causing diseases like typhoid, cholera, and diarrhea. Groundwater can also be affected by protozoan pathogens or nematodes, leading to diseases like Dracunculiasis. Even in developed countries, there are occasional risks due to pathogens like E. coli and Cryptosporidium.
Step-by-step explanation:
Surface water is often contaminated by parasites, particularly in areas with inadequate sanitation. Parasites, including protozoa, bacteria, and viruses, are major concerns for water quality, as they can cause a range of waterborne diseases.
Fecal-oral transmitted diseases such as typhoid, cholera, and diarrhea can be present in contaminated water. These diseases result from pathogens including bacteria, viruses, and protozoa found in fecal matter. Specifically, groundwater can be polluted with protozoan pathogens like Giardia intestinalis or nematodes that lead to diseases like Dracunculiasis, caused by swallowing water with infected copepods.
Sanitation measures like chlorination of drinking water can reduce the impact of these pathogens. However, in certain situations, such as natural disasters or inadequate waste management, drinking water sources can still become contaminated. This means even in developed countries with generally safe water supplies, there can be risks of contamination from pathogens like E. coli and Cryptosporidium.