^ Jump up to: a b Joseph O. Falkinham III; Elizabeth D. Hilborn; Matthew J. Arduino; Amy Pruden; Marc A. Edwards (August 2015). "Epidemiology and Ecology of Opportunistic Premises Plumbing Pathogens: Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa". Environ Health Perspectives;. 123 (8). doi:10.1289/ehp.1408692. Archived from the original on May 31, 2015. Retrieved August 1, 2015.
When a person has a blockage in their sewage system they often try to fix it themselves by adding an acid or a base such as Drano in an attempt to dissolve or dislodge the problem. These chemicals can get into the plumbers eyes when the sewage is splashed during the repair. The plumbers skin during the repair does come into contact with the sewage water. The owner of the toilet might not report to the plumber they have already tried Drano a highly caustic base .