If we find pathogenic microbes in the drinking water of an immunocompromised child who is not yet infected with this species, what guidance can we provide to the parents? Divulging information of unclear consequence can promote unwarranted action that may result in greater risk to the child. Conversations with fellow DOW scholars revealed that uncertainty is fundamental to all investigations and that we cannot let this derail our efforts to answer important questions to protect public health.

Start up funding was provided by the University of Michigan MCubed program. NK was partially supported by the DOW Sustainability Institute, the Rackham Merit Fellowship from the University of Michigan, and the EPA STAR program.

Water Infrastructure and Human Health: Bacterial communities in disinfected drinking waterNadine Kotlarz1, James Yonts1, Susan Rusinowski1, Linda Kalikin2, John LiPuma2, Lutgarde Raskin1

1 UM Department of Civil and Environmental Engineering2 UM Department of Pediatrics and Infectious Diseases

[1] Lechevallier, M. W., (1999) AWWA, 91, (1), 86-94. [2] Chiao, T. H.; Clancy, T. M.; Pinto, A.; Xi, C. W.; Raskin, L.(2014) ES&T, 48 (7), 4038-4047.

How prevalent are opportunistic bacteria in drinking distribution systems and

home plumbing?

What is the impact of chemical disinfection on the persistence of infectious bacteria in drinking

water systems?

Is disinfected drinking water a source of bacteria that

cause infections in children with Cystic Fibrosis (CF)?

Drinking Water Treatment Plant

Introduction. Most of the US population receives drinking water treated in centralized treatment plants (e.g., the Ann Arbor Drinking Water Treatment Plant services Ann Arbor) which use chemical disinfectants to kill microorganisms and minimize their regrowth in distribution systems [1]. While the implementation of drinking water disinfection represents one of the greatest engineering achievements of the 20th century, chemical disinfection presents a challenge to the sustainability of our drinking water infrastructure and may present a health risk to sensitive individuals. Specifically, chemical disinfection can select for bacteria in tap water that are not regulated federally but can cause severe illness in immunocompromised individuals (i.e., opportunistic pathogens) [2].

Ann Arbor Drinking Water

AcknowledgementsResearch Challenges

Water treatment including chemical

disinfection

Storage/distribution Householdplumbing

Source water

Consumer

Household surveys

Is human exposure to bacterial communities in

drinking water influenced by certain water use

behaviors?

Does chemical disinfection select for more diverse communities of

opportunistic bacteria?

What interventions at the household level would reduce human exposure to opportunistic bacteria in drinking water?

We are working with the Ann Arbor Drinking Water Utility

to evaluate the bacterial communities in water

samples collected before and after chemical

disinfection.

Research presentations by DOW scholars encouraged me to

expand my research to administer a door-to-door survey to collect

information about water use behaviors at the

household level.

Research Questions and Methods along the Drinking Water Flow Path

We recruited Ann Arbor homeowners (purple circles, map of Ann Arbor) to

complete a water use survey and provide water samples for chemical and

biological analysis.