White Roofs Keep Baltimore Healthy

By Cass Jacoby, RCS Reporter.  

Researchers look into the health benefits of white roofs to prove painting rowhouse roofs white is a public health right. 

This summer feels like the hottest one yet. However, 50 families who live in Baltimore rowhouses have cooler bedrooms than last year thanks to the Baltimore Office of Sustainability, who, each year applies white coating to 50 rowhouse roofs to keep the families sleeping under them cool.  

Most rowhouse roofs in Baltimore are black, reaching up to 150 degrees in the summer and radiating heat to the lower floors. White roofs work to increase the reflectivity of the roof, keeping the whole home cooler. Although white cool roofs have been promoted as a way to save energy and cool entire neighborhoods, it’s the health of the rowhouse residents that is of more immediate concern. 

Excess heat is more than an issue of comfort, it is also the cause of health problems. Johns Hopkins University has launched a $1 million study in collaboration with Baltimore City. The study will be used to fund the coating of several rowhouse roofs and hypothesize if white roofs can improve public health. Researchers will measure participants' heart rate, blood pressure, sleep and other health indicators next summer, before and after their home receives a white roof coating. The study will recruit volunteers from among those whose roofs have been coated white in Baltimore city.  

“It’s well known that high temperatures negatively affect sleep quality,” Professor Adam Spira of the Johns Hopkins University Bloomberg School of Public Health told the Baltimore Sun. “Insufficient sleep is a major public health problem, associated with an increased risk of motor vehicle accidents, depression, Alzheimer’s disease, heart disease and mortality. So, it’s really important to optimize sleep, to improve health and potentially reduce health disparities.”  

The study will provide an initial assessment of whether white roofs do have that positive effect, and if so, just how much of a benefit they provide. At this point, researchers at John Hopkins University have reason to believe that white roofs may improve sleep quality and health. 

To get beyond only fixing the hot roof problem and ensure all rowhouse roofs are coated white quickly, Baltimore needs a public health measure. Just as cities require landlords to provide heating equipment in working order during the winter, a city may require landlords to prevent excess heat in the summer in buildings with flat asphalt roofs. We already know cool roofs are the solution to cooler neighborhoods and more sustainable building practices, but could they be the key to better public health in the summer? 

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