Coolers may contain more microbes than tap water.
Commercial drinking water vending machines and coolers in public places may contain more microbes than regular tap water. This conclusion was reached by researchers from Loma Linda University, who published a review of 70 scientific studies in the journal AIMS Microbiology.
The analysis showed that bacteria can actively multiply in the nozzles and internal tubes of water dispensers just a few days after disinfection. The main reason is the filtration of residual chlorine, which inhibits the growth of microorganisms in tap water but is absent in vending machine systems.
According to the authors, with irregular cleaning and untimely filter replacement, such devices create ideal conditions for the formation of bacterial biofilms. As a result, the level of water contamination in dispensers can equal or even exceed that of the original tap water.
Researchers emphasize that vending machines require strict and frequent maintenance — from weekly to monthly disinfection depending on usage intensity. Without this, the familiar source of 'clean' water can pose a hidden health risk.
