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Making Waves In Water Epidemiology

With all of the attention in the past year focused on contami­nated city water across the country, it’s become clear that wa­ter safety is not something we can take for granted. But there are still gaps in our understanding of how drinking water becomes contam­inated, and in how to ensure access to clean water. Heather Murphy, assistant professor of epidemiology and biostatistics, is developing innovative ways to address those issues—at home and far abroad.

What’s in Your Well Water?

Many American homes don’t draw their water from a municipal water supply—instead, they rely on wells. But that doesn’t necessarily mean their water is safe. Not only is well water unregulated in the United States, but, Murphy says, many households with wells do not treat their water at all. This can leave them vulnerable to contamination by microbes.

Heather Murphy Professor of Epidemiology Temple University College of Public HealthMurphy is conducting a study of well water contamination in Pennsylvania, the state with the second-highest number of water wells in the United States. The central question she’s trying to answer: Just how many people are getting sick from viruses in their well water? Murphy says that there’s almost no existing research focused on viral water contami­nation. “That was shocking to me, given that there are 42 million people in the U.S. who are served by private wells,” she says.

But the nature of water wells makes studying them a challenge. Wells are private water supplies, so instances of sickness (typical­ly acute gastrointestinal illness) are hard to track. “To have an outbreak, you need many cases,” Murphy says. “But with someone’s personal well you’re only going to have that outbreak within the household, and those people may think it’s just the flu. So they don’t report it, and it’s not picked up.”

That makes connecting the dots difficult. But Murphy has a hunch about what may be happening. Where there is a household well, there typically is also a septic tank. She suspects that this is a source of contamination: Septic tanks often leak into surrounding soil and bedrock, carrying viruses into water wells in the area. And people who drink the water from those wells are more likely to get sick.

To test this hypothesis, Murphy and her research team are per­forming tracer studies, in which fluorescent dye is placed in septic tanks and then tracked to see whether it eventually appears in people’s wells. Murphy says that this would be the first study in Pennsylvania to confirm a link between untreated groundwater and illness.

Murphy and her team have already found bacterial contamination in some of the wells that they’ve test­ed—“even in the deepest of wells, like one that’s 700 feet deep,” she says. “There’s clearly microbial contamination getting into water sources that you’d think would be pristine.”

Based on these preliminary results and the outcomes of a similar study that Murphy conducted in Canada, she guesses there could be a significant number of people in the United States getting sick from their well water. “I expect that there’s a huge burden of disease in Pennsylvania—perhaps as many as 81,000 cases of illness each year,” she says.

Heather Murphy Professor of Epidemiology Temple University College of Public HealthProving that this microbial transfer is happening could fuel efforts to convince well owners to treat their water. “Evidence of contaminated water supplies could add weight to changing policy or introducing regulations for more rigorous testing,” Murphy says.

Water Hygiene for Developing Nations

On the other side of the world, an entirely different scene exists: Many schools in developing coun­tries have no water supply at all. In order to build this critical infra­structure, governments need to de­velop budgets for water, sanitation and hygiene (WASH) programs—something with which they may not have prior experience.

With a grant from UNICEF—the first grant ever awarded to a Temple researcher by the orga­nization—Murphy is developing and testing a costing model for WASH programs in develop­ing countries. “Many schools in these countries are built without any infrastructure for water and sanitation—no latrines, no water, just a schoolhouse,” Murphy says. “Policies need to be changed in the education sector to include those things—but to do that, you need to know how much to budget.”

The model that Murphy has developed enables health and education ministries to calculate how much these programs will cost per student, and how to best allocate funds and resources. She says that’s an important first step in paving the way for long-term WASH funding, and ultimately for better overall child health and education: “Government agen­cies need to start somewhere, so this tool helps them cost various options.”

The model is designed to work in different country-specific contexts. It accounts for all types of pro­grams, from barest bones (pro­viding just hand soap, perhaps) to full-fledged WASH infrastructure with wells, latrines and water treatment. And it can be adjusted for urban and rural locations, for schools of all sizes, and for differ­ent gender ratios—all important factors in determining what infra­structure is needed.

For Murphy, the real work is just beginning. UNICEF has estab­lished pilot programs in Indonesia, Ghana, Myanmar, Nepal and Co­lombia, where it is working with health and education ministries to implement the model, assess its effectiveness, and look for ways to improve its accuracy and versatil­ity. Murphy says that the govern­ments in these pilot countries are excited to be building better public health infrastructure: “Now they don’t have to say, ‘Well, we just can’t afford it.’”

Learn more about research in the Department of Epidemiology and Biostatistics here.

Posted:  November 2, 2016