Most backflow incidents that cause health problems involve

• A. Respiratory problems
• B. Gastrointestinal problems
• C. Neurological effects
• D. Skin irritation

Answer: (B)

Backflow contamination most often leads to gastrointestinal illness because people typically become sick after drinking the contaminated water. When fecal matter or other contaminants enter the potable supply, ingestion is the main exposure route, and the pathogens involved—bacteria, viruses, and parasites—cause symptoms like diarrhea, stomach cramps, nausea, and vomiting. While exposure to contaminated water can sometimes cause other effects, those GI symptoms are by far the most common health outcome of backflow events.