Renewal of NIEHS grant paves way for new research on how complex environmental exposures affect health

Douglas Dockery (left) led the NIEHS Center for 11 years; Marc Weisskopf is current director

August 8, 2019 – With the renewal of a major federal grant, Harvard T.H. Chan School of Public Health’s NIEHS Center for Environmental Health will focus on a broad new objective—the exploration of how a wide variety of environmental exposures, in combination, affect human health.

The $10.2 million grant provides the 55-year-old Center with another five years of funding to encourage new science, foster collaboration, and support centralized resources such as labs and scientific equipment for environmental health research. The Center is the oldest of 20 “core” research centers across the country supported by the National Institute of Environmental Health Sciences (NIEHS) and, as the recipient of only the second grant awarded by the National Institute of Health, has the distinction of having NIH grant number ES-000002.

“This Center is considered a shining jewel of the Department of Environmental Health,” said Marc Weisskopf, Cecil K. and Philip Drinker Professor of Environmental Epidemiology and Physiology. Weisskopf recently took over as Center director after Douglas Dockery, John L. Loeb and Frances Lehman Loeb Research Professor of Environmental Epidemiology, stepped down after 11 years in the role. “This grant has facilitated a lot of our science for 55 years,” Weisskopf said.

The Center has propelled the research of environmental health scientists not just at Harvard Chan School but throughout Harvard University, the University’s teaching hospitals, and other institutions such as Yale, Dartmouth, Northeastern, and Boston University. “The Center provides core resources to encourage people from multiple disciplines to really think about environmental issues when they’re doing their research—people who had not necessarily been thinking about environmental health as a risk factor,” Dockery explained.

Research with impact

Over the past five-plus decades, the Center has supported research in the Department of Environmental Health’s focus areas of air pollution, metals, and organic chemicals. The Center helped support, for example, the landmark Six Cities Study, led by Dockery, which found a strong link between air pollution and mortality risk and helped pave the way for strengthened U.S. regulations on fine particulate matter in the air.

Center investigators, led among others by Howard Hu in the past and Weisskopf now, have been pioneers in the non-invasive measurement of lead in bone and other tissues using X-Ray Fluorescence (XRF) and the use of that approach to examine the connection between lead exposure and outcomes like cardiovascular disease and cognitive function. Other Center researchers have conducted studies that have looked at mercury in the environment. Elsie Sunderland, for example, found that hydroelectric plants in Canada that require the flooding of land can trigger increased levels of methylmercury, a neurotoxin, in the water, which then works its way into the food chain.

Other examples of Center-supported work include:

  • Lindsay Jaacks’s work on the association between exposures to organic pollutants, such as polychlorinated biphenyls (PCBs) and organochlorine pesticides, and diabetes in developing countries;
  • Tamarra James-Todd’s research on how hormone-disrupting chemicals might affect mothers’ heart and metabolic health during pregnancy and contribute to disease later in life;
  • Maitreyi Mazumdar’s research on whether prenatal exposure to arsenic may increase risk of infant neural tube defects;
  • Wanda Phipatanakul’s examination of the effectiveness of air cleaning in schools in reducing the prevalence and severity of asthma;
  • Catherine Racowsky’s collaboration with Russ Hauser, chair of the Department of Environmental Health and director of its organic chemicals research core, to study the impact of bisphenol A (BPA) on human egg quality.

Complex exposures

The new award will help propel research that will examine not only exposures to single toxins such as lead or pesticides, but also how complex exposures to a variety of substances combined with other factors—such as green spaces or access to healthy food—can impact health. “We think that looking at complex exposures is going to be one of the next vanguards of environmental health,” said Weisskopf.

“The real-world lived experience is very complicated and has many exposures at once,” he explained. “Some of these exposures are to things that we haven’t traditionally focused on in environmental health, such as what a neighborhood is like—the social stressors, the amount of green space, traffic, or the state of buildings and trees in the area. But these are things that are out there in the world, so we want to know how they act on us, and when you have all of these things happening together, we want to know what health effects can occur.”

Weisskopf admitted that it’s not an easy task to analyze the combined health effects of, say, 20 different types of chemicals and other environmental exposures. But he said that biostatisticians at Harvard Chan School have already been working on statistical methods to quantify and characterize these complex exposures.

Experts from various Harvard Chan departments will contribute to future environmental health research funded by the Center. For instance, Nancy Krieger, professor of social epidemiology, will help researchers better understand social contexts and how their health effects can be measured. Jukka-Pekka (JP) Onnela, associate professor of biostatistics, will provide expertise in using smartphone technology to help detect environmental exposures. Smartphones can be used to construct precise mobility traces of people which, when combined with information about environmental hazards in specific locations, can be used to estimate individual-level exposures to substances such as air pollutants. Onnela can also offer guidance on using smartphone data to quantify behaviors such as sleep, physical activity, and social interactions.

Even the microbiome—the millions of microbes that live inside the human body—could figure in future environmental health research, said Weisskopf. He explained that the microbiome could be considered an “environmental exposure” because it includes separate organisms living inside our bodies that can affect our health. On the other hand, the microbiome could also be seen as a part of us that can be affected by exposures outside our bodies, like particles, metals, or organics.

‘A significant backstop’

Both Dockery and Weisskopf emphasized that NIEHS Center funding helps develop the careers of young investigators, by providing pilot grants for innovative research as well as assistance with writing grants and building professional networks. This type of support has a multiplier effect, according to Dockery. Over the past decade, the Center gave out 100 pilot project grants, and those have led to 33 new NIEHS grants for individual researchers and more than 150 publications. Over the past five years, 14 Center-supported researchers got career development awards from the National Institutes of Health, and 27 were appointed as faculty members at other institutions.

“We’ve really seeded environmental health, not only at Harvard, but at institutions across the country,” Dockery said.

Dockery is proud of how the NIEHS Center has been able to develop and support a new cohort of environmental health researchers over the past 50 years. Thanks in part to their work, he said, “We’ve seen incredible improvement in terms of cleaning up the environment—reducing air pollution, reducing water pollution, and identifying new hazards.”

But with new chemicals and new environmental hazards being introduced all the time, Dockery said that “we can’t relax our vigilance,” especially given current attacks on science by industry and the current administration. “This grant is a significant backstop in this climate where the EPA is being cut back and you see attacks on science,” he said. “It provides us some assurance that we’re going to be able to move forward over the next five years.”

Karen Feldscher

photo: Kent Dayton