Schools are opening again after months of not being used, and the novel coronavirus is not the only problem they have to address, Legionella bacteria may be found contaminating the water supply, informs The New York Times.
As schools were getting ready to reopen at the end of August, officials detected Legionella in several schools in Ohio and Pennsylvania, an unusual finding according to Andrew Whelton, Associate Professor of Cilvil, Environmental and Ecological Engineering at Purdue University (Indiana), who has been looking into the consequences of lockdown for water systems.
Found naturally in freshwater environments, Legionella can become a health concern when it grows in a building’s water system, such as in faucets and shower heads, from where it can spread in droplets that people breath in. It can cause a series type of pneumonia known as Legionnaires’ disease. While most healthy people exposed to Legionella will not get sick, those older than 50 or with certain health issues are at increased risk, according to the Centers for Disease Control and Prevention (CDC).
While occupancy is usually low during the summer vacation, many school facilities are used for summer school or other activities. But many school buildings have been closed since the pandemic swept across the US last March. Stagnant water in plumbing during lockdown is a concern, say experts, and schools don’t necessarily have plans or effective guidance from authorities to deal with the aftermath of a lengthy shutdown. Although last May the CDC issued guidance to ensure the safety of building water systems and devices after a lengthy shutdown, Dr Whelton believes the guidelines are vague enough that schools can do a lot or a little in terms of prevention and say they are compliant.
Moreover, measures to control the risk of coronavirus infection such as closing drinking fountains or sport facilities could inadvertently increase Legionella risk by prolonging the time water is left to stagnate in plumbing.
Methods of dealing with Legionella are flushing and thermal shock, although the latter one has been questioned. Flushing with fresh water brings chlorine into the water system, and has to be done more than once to eliminate Legionella. The bacteria form biofilms that protect them, and they may proliferate again after the chlorine dissipates. Eliminating the bacteria from the water system can take weeks.
Water should be tested to see if measures have been effective, and the testing procedures are also important. Legionella will not show if testing is done directly after flushing, but that is not clear in the guidance, and so the testing done could be ineffective. The problem is schools may not have a budget for testing, and may do it ineffectively. Furthermore, there is no requirement to test for Legionella, nor to report the findings. Dr Whelton thinks that if more schools tested for Legionella, more would detect the problem, and recommends parents to ask schools about it.
