Nearly half of soda machines nationwide are contaminated with dangerous levels of bacteria, a first-of-its-kind study suggests.

Researchers in California say the problem is being ‘overlooked’ after finding E. coli, salmonella, and Pseudomonas aeruginosa, which have been linked to serious health consequences like pneumonia, meningitis, and other infections on the machines.

The team tested samples from self-serve soda machines, water vending machines, and outdoor tap water sources in the rural eastern Coachella Valley area.

About three-quarters of the samples exceeded limits set by the Environmental Protection Agency (EPA).