The water cycle as a source of pathogens.
D000818:Animals; D000829:Animals, Domestic; D001424:Bacterial Infections / Q000635:transmission*; D004326:Drinking; D006801:Humans; D010272:Parasitic Diseases / Q000635:transmission*; D011998:Recreation; D012722:Sewage; D014777:Virus Diseases / Q000635:transmission*; D014871:Water Microbiology; D014881:Water Supply
D012722:Sewage