A primary health risk associated with microorganisms in drinking water is which of the following?

• A. cancer
• B. acute gastrointestinal diseases
• C. birth defects
• D. nervous system disorders

Answer: (B)

Microorganisms in drinking water primarily cause acute gastrointestinal diseases because ingesting contaminated water commonly irritates and inflames the digestive tract, leading to diarrhea, vomiting, cramps, and dehydration. Pathogens such as norovirus, Giardia, Cryptosporidium, and certain bacteria are well-known culprits in waterborne outbreaks and tend to produce rapid GI symptoms after a short incubation. While other health effects can occur with different exposures, they are not the typical outcome of ordinary waterborne contamination. So the main health risk is acute gastrointestinal illness.