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Annual Publication of the University of Pittsburgh Swanson School of Engineering
From Treatment to Tap Sarah Haig Receives a Career Award to Improve the Treatment Processes for Drinking Water
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efore it even touches our lips, drinking water is purified through a series of processes referred to as the “treatment train” at a centralized treatment plant. Utilities then add a disinfectant like chlorine or chloramine to the water to control the regrowth of microorganisms in both the distribution system and building plumbing. Despite these treatments, drinking water that meets state and federal regulations still contains many types of bacteria. Though most surviving bacteria are harmless, some like drinking water-associated pathogens (DWPIs) – which
predominantly impact the immunocompromised – cause more than 145,000 human infections annually and cost the United States billions in healthcare costs. Assistant Professor Sarah Haig received a $550,000 Faculty Early Career Development Award from the National Science Foundation (NSF) to learn how some DWPIs can survive drinking water treatment processes and determine better treatment processes to stop them from entering the human body. According to NSF, the CAREER award is its “most prestigious in support of early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.” The Dangers of DWPIs Several DWPIs are concerning; however, Legionella pneumophila and nontuberculous mycobacteria (NTM) cause the most respiratory infections and cost the greatest amount to treat. The human body can stop these pathogens from entering its system, but people with immunosuppressive conditions like cancer, HIV, or preexisting respiratory issues such as COPD have a heightened chance of these pathogens evading their biological defense mechanisms. One possible
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explanation is the overlap in mechanisms used by these pathogens to evade both drinking water treatment and the human immune system. “Disinfection processes kill microorganisms by damaging cells through a process called chemical oxidative stress,” Haig explained. “The human immune system uses the same procedure to kill continued on next page > > >