The sudden and sweeping closures of schools, factories, businesses and government offices that have come as a result of the COVID-19 crisis have created an unprecedented decline in water use within existing buildings. And the resulting lack of chlorinated water flowing through pipes, combined with irregular temperature changes, have created conditions ripe for the bacteria that causes Legionnaires’ disease, US News reports.

With the extended shut down of commercial buildings expected to last for at least several more weeks, public health experts are, according to US News, “urging landlords across the globe to carefully re-open buildings to prevent outbreaks of the severe, sometimes lethal, form of pneumonia.”

Molly Scanlon, an Arizona environmental health scientist leading the American Institute of Architects’ coronavirus task force tells US News, “After surviving COVID-19, who wants to open a building and have another set of significant safety issues?” 

Building safety professionals recommend thoroughly flushing water pipes for at least 30 minutes upon reoccupation of their shuttered properties.