Our Berkeley Family of Global Citizens

The legacy of a public health program is reflected in the mark it leaves on the world, not only in terms of the research it produces but the studies, discoveries, relationships, and innovations it inspires. Improving global health means asking, over and over, do we know enough about a problem to do something about it?

For three long-term faculty members, who together represent more than 80 years with the School of Public Health, answering that question has been a winding journey. They are committed to understanding complex challenges—the harm of air pollution, the molecular underpinnings of infections, the spread of vaccine-preventable diseases. At the same time, they train the next
generation of passionate, curious souls to identify pressing global health problems, search for solutions, and ask the right questions.


The biggest environmental health risk to people worldwide isn’t sanitation, lack of access to clean water, or diseases like malaria—though all of those are heavy-hitters. It’s air pollution, which the World Health Organization blames for about one in every eight deaths worldwide; it kills more people annually than smoking, diabetes, and car accidents combined.


“Air pollution is up there with the big boys,” says Professor Kirk Smith, who knows more about the risk than almost anyone. For 40 years, Smith, a global environmental health expert, has been at the forefront of efforts to understand the causes and reach of deadly air pollution—and do something about it. But his research is only half the story: Smith has also trained more than a generation of researchers who have now gone on to help shape global health policy around the world.

“It’s been a lifelong learning experience,” says exposure scientist Jim Zhang at the Duke Global Health Institute, who worked with Smith as a postdoctoral researcher in the 1990s. “He made a profound impact on me in terms of how to really look at the world. What’s the big picture?”

Sumi Mehta, an epidemiologist at Vital Strategies, a nonprofit charity organization, says Smith’s approach invited students and advisees to be part of the research process. “It was always meant to be a collaboration,” she says. “Realizing that the problems are so huge, we work together to solve them.” She says Smith also worked to strengthen the role of their colleagues in middle- and low-income countries, to ensure that every project was an international collaboration.

Smith, who earned his MPH and PhD from UC Berkeley, started his career as a health scientist studying the risk associated with nuclear reactors, but in the late 1970s realized that air pollution posed a much bigger threat to human health.

“You could have a Chernobyl accident every month, and it still wouldn’t produce one-tenth of the harm we find from air pollution.”

“You could have a Chernobyl accident every month, and it still wouldn’t produce one-tenth of the harm we find from air pollution,” he says. A few nuclear accidents like the one at Chernobyl would immediately shut down the nuclear industry, he says, but policies aimed at reducing air pollution are slow to emerge, and often ineffective.

That pivot—from nuclear reactors to air pollution—exemplifies one of the guiding mantras that Smith teaches his students: Follow the risk, not the money. Zhang says he still selects research projects with Smith’s principle in mind.

Smith is nothing if not dogged. Starting in the 1980s and 1990s, he produced some of the earliest evidence of the harm from smoke from wood-fired cook stoves in low-income countries. But his voice wasn’t heard, recalls Zhang. “I remember when I presented some work I did with Kirk, and we often found only two or three people in the room,” he says. “The rest of the people didn’t hear us, they weren’t interested, the problem was too far away from their lives.”

Immediately after his first studies in the 1980s, Smith began designing trials and applying for funding. “Given this pollution,” he thought at the time, “what kind of health work should we do?” His applications for a randomized trial were initially denied. Seventeen years later, his persistence paid off with a randomized trial in Guatemala of how attention to stove design could reduce the risk of childhood pneumonia.

Now, at least 10 randomized trials are in progress worldwide, all aimed at reducing the harms caused by wood-fired cook stoves. Household air pollution is recognized as a major threat that causes millions of premature deaths every year, with the largest risks among pregnant mothers and young children.


Smith has studied pollution inside and outside homes; he’s showed the extent to which they’re connected, and argued that policies aimed at reducing widespread ambient pollution must first address the influence of household fuels. With his students and collaborators, he has led studies of the problem in 20 countries in Asia and Latin America; their work has resulted in hundreds of articles in journals and books on topics ranging from air pollution to climate change. He’s also spearheaded the design and implementation of small, smart, fast, and cheap air sensors for people in low-income countries.

His awards are legion: He helped produce the third, fourth, and fifth reports of the Intergovernmental Panel on Climate Change, which in 2007 shared the Nobel Peace Prize for its work disseminating knowledge about anthropogenic climate change—and devising strategies to slow it down. His research set the stage for a generation of investigators who are not only probing the science behind the problem but also designing new stoves, testing new fuels, and working with policymakers to improve global health through legislation.

Beth Altshuler, a former student, says that Smith’s teaching and guidance helped influence how she approaches some of her own work at Raimi + Associates, an urban design research firm in Berkeley that focuses on health, sustainable, and equitable communities. “Through Kirk, I have the fluency to make big climate science concepts really relatable to everyday things that people care about in their neighborhoods.”

Ajay Pillarisetti, a postdoctoral researcher in Smith’s lab, currently works on a project led by Smith in Maharashtra, India, to provide clean fuel to pregnant women and find ways to encourage them to use it. Pillarisetti uses the phrase “intellectually nimble” to describe Smith’s approach to research and mentoring. “He’s open to new thinking, and he pushes back appropriately when we’re off base,” he says. “The group is focused on working on problems where there’s substantial risk, and thinking about how the science can be applied to protect public health.”

That idea—using the science to protect the population—has become even more important in Smith’s current work. His pioneering efforts have inspired decades of research into the harm and extent of air pollution. They’ve also led to attempts by other researchers to look for solutions, like designing better stoves and finding ways to encourage cleaner fuel use among the poor. But they’re not always successful.

“There are graveyards full of these interventions,” Smith says. “I went to a house once in China that had seven different so-called improved stoves, left in the house after various programs had gone through. They were used for storage; they held sacks of grain.”

Since 2014, when he completed a sabbatical in China and India, he’s switched his focus away from trying to measure the extent of the health effects and toward affecting real change. “There’s no reason I should be doing the same thing now I was doing 30 years ago,” he says. “The big issue now is how do we fix it?”

To that end, he’s publishing more papers on policy and fewer on science; he’s meeting with foreign leaders and helping draft legislation that will protect the world’s most vulnerable populations. This has been most successful so far in India, where a program is underway to introduce clean fuels to 100 million poor families, the largest intervention of its kind to date.

His field and policy work continue in India, China, and Mongolia, as well as through the work of the dozens of advisees and hundreds of students who remind themselves, and their own advisees: Follow the risk. That’s where the change has to happen.

Lee Riley’s Interdisciplinary Toolbox

Professor of Epidemiology and Infectious Diseases Lee Riley’s research spans decades, continents, and even disciplines. His resume is weighted with honors that speak to the reach of his work: He’s a fellow of the American Association for the Advancement of Science, the Infectious Disease Society of America, and the American Academy of Microbiology. His hundreds of published papers, his co-authored 2016 book Slum Health, and his dozens of global public health advisees working around the world all orbit the same urgent questions:

How can epidemiologists identify infectious diseases with global importance, and how can that research improve human health?

Those questions first took root in his mind when, in the early 1980s, he landed in the slums of Sao Paolo, Brazil, to work on a project with the CDC’s Epidemic Intelligence Service, or EIS. He was fresh out of a residency at Columbia University, and one of his first assignments took him to join a microbiologist studying diarrhea in children, most of whom lived in the city’s shantytowns.

The diseases of slums would shape his work for decades, but those two years in the EIS exposed him to something else: the burgeoning field of molecular epidemiology. Part of his responsibilities involved analyzing the genotypes of bacterial isolates. Those studies, in turn, led him to become fascinated with another field—microbiology pathogenesis, or the cell-level understanding of how germs cause disease.

By the time Riley was recruited to Berkeley, in 1996, he’d become known for his work combining epidemiology with pathogenesis research. His research questions—now, as then—arise from epidemiological work and studies of infectious disease.

“My inspirations are drawn from real-world public health issues,” he says. “Unanswered questions in public health ultimately end up having to be addressed by bench research.”

He’d also become known for analyzing the health risks of slums from the perspective of a microbiologist. Riley returned to Brazil again and again, establishing new projects designed to probe the molecular underpinnings of diarrhea, tuberculosis, and leptospirosis.

“I thought, there’s something about slums that engenders these diseases,” he recalls. “We need to look more closely at the slum factors that contribute.” Much of his research on understanding and eradicating biases in slums is highlighted in the 2016 book, Slum Health: From the Cell to the Street, which he co-authored with fellow Berkeley Professor Jason Corburn. The book unites Riley’s biological research of the molecular roots of infectious diseases with Corburn’s focus on urban design.


Epidemiologist Brendan Flannery, now with the CDC’s Global Immunizations Division, was one of Riley’s first advisees at Berkeley, in the late 1990s. Flannery now evaluates flu vaccines, but during his time at Berkeley, he visited Brazil multiple times for Riley’s projects, including identifying potential targets for a leptospirosis test. They discovered that cases of leptospirosis surged after rains in people who lived in slums that were subject to flood, in part because of contact with rat urine.

Riley recruited more Brazilian scientists to the effort over time, and Flannery says the research flourished. “The ability to exchange research ideas with people from all over the world that Lee brought together in his laboratory, working on different questions, was a really rich experience,” says Flannery. (He credits Riley with influencing his life in other ways, too: He married a woman he met in Brazil, and they and their kids often return.)

“That was the coolest thing in epidemiology. It totally changed my life.”

Epidemiologist Sara Tartof, a former student now studying vaccine efficacy at Kaiser Permanente, says Riley approaches science with an unending and infectious curiosity. “He’s very, very creative,” she says. “A lot of people get stuck thinking, ‘this is the way we’ve understood something for a long time.’ I think Lee has a lot of fun blowing that stuff up. I try to keep that level of creativity and open-mindedness in my own work.”

At Riley’s urging, Tartof joined the EIS after her education at Berkeley. “That was the coolest thing in epidemiology,” she says. “It totally changed my life.”

Many of Riley’s students, inspired by his creativity, have gone on to make their own mark in the world. In 2001, says Riley, no one really knew the origins of the E. coli pathogens that caused urinary tract infections in women. Amee Manges, then a Berkeley student, came to Riley and said she wanted to find out. With Riley advising, Manges looked for the pathogenic fingerprints in the urine of women with UTIs—first at Berkeley, then at other schools.

What they found was a shock: Biologists have identified tens of thousands of different types of E. coli, but half the women with UTIs were infected with the same few strains, which were resistant to the antibiotics used for treatment at the time. More recent work has revealed that these strains may be present in meat—especially chicken—which suggests that women could acquire UTIs as a food borne disease.


That project revealed important new research questions for scientists around the world. “Why are these particular five strains all over the world?” he asks. An answer to that question, from a microbiology standpoint, could point to new ways of preventing UTIs and other diseases.

This case shows the power of Riley’s combination of pathogenesis and epidemiology: The study begins with a public health observation, leads to a microbiological investigation, and ultimately produces new treatment strategies.

That project also relates to what Riley says is a crisis waiting to explode: antimicrobial resistance. Rising use of antibiotics and other drugs that suppress the immune system has resulted in a growing number of “superbugs”—bacteria and other pathogens that don’t respond to available treatments.

“Something that a lot of people haven’t realized yet is that we’re running out of new antibiotics,” he says. “This is going to be a huge issue in the future.”

Riley says his job is to look to the future, devising solutions for big problems on the horizon. The uptick in homelessness in the Bay Area, for example, looks eerily similar to what he’s seen in the slums in other countries. “Of course, it hasn’t reached the proportions we’ve seen in Brazil and India, but I wouldn’t be too surprised if this problem were to continue to increase, and we see the same things here that we see in Brazil, in terms of infectious diseases.”

The reason for the problem is the same in both places, he says: “There’s a huge disparity between the wealthy segment of society and the poor segment of society,” he says. That divide, according to Riley, is what drives the homeless problem, and what drives the rampant spread of infectious diseases in poor areas.

“Those problems are going to be a lot more urgent soon,” says Riley.


When Art Reingold’s phone rings or an email appears in his inbox, it’s likely as not to be a former student. Maybe it’s Jordan Tappero checking in, who until last December was the director of the Division of Global Health Protection at the CDC. After more than 25 years in Atlanta, Tappero now studies neglected tropical diseases at the Gates Foundation. Or maybe it’s epidemiologist Aubree Gordon at the University of Michigan School of Public Health, calling at dawn on a Saturday to get career advice.

Or any one of dozens, if not hundreds, of students-turned-friends looking for his trusted perspective. Tappero hasn’t been in Reingold’s class as a student since the mid-1990s, and Gordon finished her PhD at Berkeley years ago.

“He’s a mentor, a friend, and a colleague. He’s special,” says Tappero. “You don’t feel like the class is over when you get your grade and you walk away. I know I’m not the only one who picks up the phone and says, ‘Hey Art, what do you think of this?’”

Reingold acknowledges that he teaches and mentors a lot of students. “I have a reputation for teaching too much,” he says. “I get quite involved in teaching students how to think epidemiologically.”

Reingold sees teaching as a critical part of his contribution to global public health. It’s not the only part, of course. He’s studied the relationship between HIV and tuberculosis in the developing world, as well as opportunistic infections in AIDS patients. Reingold was part of a group of researchers at the CDC who, in the early 1980s, investigated a disease that made healthy women sick and was associated with the use of tampons, now known as Toxic Shock Syndrome. He also worked on understanding Legionnaires’ disease and meningococcal meningitis, as well as other infections.

“We have to collect the evidence and make it available, as opposed to dismissing people’s concerns. We have to find interventions that are both effective and safe.”

His work has helped shape policy and recommendations at the CDC and beyond. He advised the World Health Organization on issues related to vaccine-preventable illnesses, one of the foci of his research, and in 2003 was elected to the Institute of Medicine of the National Academy of Sciences. More recently, he’s helped develop strategies around immunizations and, in a climate of increased distrust of vaccine safety, how to convince people to protect themselves and their children.

“We have to collect the evidence and make it available, as opposed to dismissing people’s concerns,” he says. “We have to find interventions that are both effective and safe.”

Like many epidemiologists, Reingold participated in the CDC’s two-year Epidemic Intelligence Service; he still wears a small earring that depicts the program’s logo, which is a shoe with a hole in its sole. It’s a nod to shoe-leather epidemiology, or using the tools of public health to solve problems. “We called it medical detective work,” he says. “It changed my career plans and changed me as a person. It was like the Hollywood version of epidemiology. Can you answer the question that solves
the problem?”

That notion—of putting methodological tools to use in real-world settings—guides his work. “I work very closely with people in the real world of public health,” he says. That includes county and state health officials in California and beyond. He’s worked with health offices on issues ranging from vaccine policy to training all over the world—in Brazil; in Uganda, Zimbabwe, and other African countries; in India.


Those personal networks enliven his classes, too. If students are studying disease outbreaks and an outbreak occurs in a nearby county, says Tappero, it’s not unusual for Reingold to haul his students out to conduct research firsthand, in the field. “He has a real focus on getting you into the field,” says Tappero. “He made it fun. He made it feel like I’m going to take what I’m learning and go use it right away.”

Reingold has also helped shape the careers of students around the world through Berkeley’s Fogarty AIDS International Training Program, which funds talented scholars from India, Uganda, Thailand, Zimbabwe, and other countries to study epidemiology at the School of Public Health.

“This is an incredible global footprint and contribution,” says Madhukar Pai of the program. He and his wife, Nitika Pai, received fellowships in 2000. “This opportunity was the single biggest break we have had in our career, and it changed our lives,” he says. “Art played a key role in our training, with his mentorship, teaching, and inspiring leadership.” Pai is now a tenured professor at McGill University and director of Global Health and the TB Centre at the university; his wife is a professor who continues to study HIV/AIDS there.

For Reingold, public health work boils down to asking the right questions, which is what he trains his students to do. “The challenge is to identify questions that haven’t been answered already, where somebody would care about the results, and they could influence policy or decision-making,” he says. “Identifying a good question and then deciding the best approach to answering that question is the single greatest challenge to making an impact in our field.”

In many cases, he says, the question presents itself. A disease erupts in an outbreak, or a lot of people get sick for some unknown reason. In his classes, Reingold goes to great lengths to teach his students how to recognize the core issue that they want to study. What he doesn’t do, however, is hand them question to investigate.

“My approach is a little unusual, in that I tend to ask students what questions they think are important,” he says. “Then I can help them refine those questions or think about ways to answer them.”

Kunchok Dorjee, a former advisee and now a postdoctoral researcher at Johns Hopkins, is working on a tuberculosis elimination campaign among Tibetan refugees in northern India. He credits Reingold with showing him how to find the resources he needed to push his own research forward.

“He gives you the independence to pursue your ideas and build on them,” says Dorjee. “He would at the same time chime in time and time again to give you direction.” Dorjee says he also felt supported personally by Reingold. Dorjee moved his family to California from India to pursure his PhD in Epidemiology at Berkeley, and his first son was born while he was in school. “Things were challenging, but Art really made me feel supported. His advice was invaluable.”

Gordon, at Michigan, says she often encounters Reingold’s networks. “I’m constantly interacting with people at meetings and his name will come up,” she says. “It’s just amazing how many lives he has influenced and what an amazing mentor he’s been to these people, both formally and informally.”