https://phys.org/news/2020-04-coronavirus-pandemic-sick.html
The
coronavirus pandemic might make buildings sick, too
by
Caitlin R. Proctor, Andrew J. Whelton and William Rhoads, The
Conversation
While millions of people are under orders to stay
home amid the coronavirus pandemic, water is sitting in the pipes of empty
office buildings and gyms, getting old and potentially dangerous.
When water isn’t flowing, organisms and
chemicals can build up in the plumbing. It can happen in underused gyms, office buildings,
schools, shopping malls and other facilities. These organisms and chemicals can
reach unsafe levels when water sits in water pipes for
just a few days. But, what happens when water sits for weeks or months?
There are no long-term studies
of the risks and only minimal guidance to
help building owners
prepare their water for use again after a long shutdown.
As researchers involved in building water safety,
we study these risks and advise building owners and public officials on
actions they can take to reduce the potential for widespread waterborne
disease. A new paper highlights
these issues and our concerns that the COVID-19 stay-at-home orders may
increase the chance of harmful water exposure when people return.
What happens
when water gets old?
Just like food that sits in a refrigerator for too
long, water that sits in a building’s pipes for too long can make people sick.
Harmful organisms,
like the bacteria that cause Legionnaire’s disease, can grow. If not
maintained, devices like filters, water tanks, heaters and softeners can
become organism incubators.
With certain pipe materials, water can accumulate
unsafe levels of lead and copper, which can
cause learning disabilities,
cardiovascular effects, nausea and diarrhea.
Drinking this
water is a problem, but infections can also result from inhaling harmful
organisms. This occurs when water splashes and becomes an aerosol, as can
happen in showers, hot tubs and pools and when flushing toilets or
washing hands.
Some of these organisms can cause pneumonia-like diseases,
especially in people who have weakened immune systems.
Water inside a building does not have an expiration
date: Problems can develop within days at individual faucets, and all buildings
with low water use are at risk.
Keep the water
flowing
To avoid water issues, “fresh” water must
regularly flow to a building’s faucets. Most U.S. water providers add a chemical disinfectant
to the water they deliver to kill organisms, but this chemical disappears
over time.
Medical facilities, with their vulnerable
populations, are required to have
a building water safety plan
to keep water fresh and prevent growth. Schools, which have long periods of low
use during the summer, are advised to keep
water fresh to reduce water’s lead levels.
Health agencies in the U.S., Canada, England, Europe and some states have
released recommendations in recent weeks, advising that building water be kept
fresh during COVID-19 stay-at-home orders. There’s some debate over the best
way to do that, but the core message is the same: Do not let water sit in
buildings. Flushing
accomplishes several goals. Credit: Caitlin Proctor/Purdue University
If
water isn’t being used in a building, intentionally flushing the building to replace all the old water
with new water can be done at least weekly.
It also helps remove sediments that
accumulate along pipe walls.
Faucets, water heaters and softeners, appliances
such as refrigerators, toilets and other water systems, including cooling
towers, all need to have water turnover. Some of these can require specialized
attention. Faucet aerators should be removed because they accumulate materials and
slow down the flow.
How long flushing takes depends on the building’s
piping design, devices and the speed of water exiting the faucets. All
buildings are different.
It took more than 80 minutes of
flushing to draw fresh water to the farthest faucet of one 10,000-square-foot
building. In another building, it took 60 minutes just
to get fresh water from
the water meter to the basement of a building 30 feet from the street. A single
large building may take hours or days to clear.
Easier to avoid
contamination than clean it up
For building managers who haven’t been running the
water during the pandemic, the water sitting in pipes may already have
significant problems. To perform flushing, safety equipment, including masks, currently
in short supply,
might be needed to protect workers.
A slow “ramp-up” of
the economy means buildings will not reach normal water use for some
time. These buildings may need flushing again and again.
Shock disinfection, adding a high level of
disinfectant chemical to the plumbing to kill organisms living in it, may also
be necessary. This is required for new buildings and
is sometimes done when water in new buildings sits still for too long.
Inexpensive chemical disinfectant tests can help
determine if the water is “fresh.” Testing for harmful organisms is
recommended by some organizations.
It can take several days and requires expertise to interpret results. Metals
testing might be needed, too. Public health departments can provide specific
recommendations for all of these actions and communication of risks.
The need for
standards and water safety
Water left sitting in the pipes of buildings can
present serious health risks.
Standards are lacking and very much needed for
restarting plumbing and ensuring continued water safety
after the pandemic passes.
Right now, building managers can take immediate
action to prevent people from becoming sick when they return.
Explore
further
Water quality could change
in buildings closed down during COVID-19 pandemic, engineers say
Provided
by The Conversation
This article is republished from The Conversation under
a Creative Commons license. Read the original article.