A study has shown that more bacteria are present in water
dispensed from hands-free electronic-eye faucets, than in that
from conventional faucets
(Photo: SCA Svenska Cellulosa Aktiebolaget)
Just three years ago, a study conducted by the University of
Westminster, London, determined that the "hygenic" warm air hand
dryers commonly found in public washrooms actually left users
with more bacteria on their hands than if they'd simply
used paper towels. Now, it seems that the good name of
hands-free electronic-eye faucets is being similarly besmirched
– researchers at The Johns Hopkins Hospital in Baltimore have
discovered that water coming from such faucets contains more
Legionella bacteria than that dispensed by conventional
fixtures. Their theory is that the high-tech faucets' complex
inner workings are to blame.
The hands-free faucets use a sensor to detect when a user's
hands are present, at which point the water will automatically
come on for a preset amount of time. Given that the whole
process involves no touching of anything, it would indeed appear
to be more hygienic than a system in which multiple users touch
hot and cold water handles with their unwashed hands. The folks
at Johns Hopkins and other U.S. hospitals obviously thought so,
and proceeded to introduce the faucets in patient care and
public areas over a decade ago.
When Johns Hopkins staff were testing how often their water
system needed to be flushed, however, they were surprised to
discover Legionella growing in 50 percent of the
cultured water samples from 20 hands-free faucets, as compared
to only 15 percent in samples from 20 manual faucets in the same
areas. While Legionella pose little risk to healthy
individuals, they can cause serious infections in people with
weakened immune systems.
The water from the traditional faucets was also found to
contain just half the amount of other types of bacteria.
Although the reasons for the difference are unclear, the
researchers suspect that the complex valve components of the
newer faucets offer more surface area and hiding places for
bacteria, which remain present even after standard hospital
water disinfection methods. Conventional faucets, on the other
hand, have few internal parts.
Johns Hopkins has since replaced all 20 of its newest
hands-free faucets with manual models, and is in the process of
replacing 100 similar faucets throughout the hospital. The
research team now plans on working with manufacturers of
hands-free faucets, to devise new ways of building them so that
they can be more easily and thoroughly cleaned.
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