Environmental health researcher studies effects of air pollution in and out of the womb


Department of Population and Public Health Sciences

Publish date

April 5, 2019


This post is part of our National Public Health Week series! We’re putting the spotlight a different area of public health each day. We hope you are as inspired as we are by the featured change-makers in this series.

Carrie Breton ScD, Associate Professor of Population and Public Health Sciences, USC

Pictured: Carrie Breton ScD, Associate Professor of Population and Public Health Sciences. Photo courtesy Carrie Breton.

Health issues arising from climate change and air pollution are getting more attention than ever, but what about the risks even before birth? At the Maternal And Developmental Risks from Environmental and Social Stressors (MADRES) Center, researchers including Carrie Breton, ScD, associate professor of preventive medicine, have become increasingly concerned with the impact environmental factors and stressors can have in utero.

What area of public health does your work focus on?

I conduct research centered on understanding how early-life environmental exposures affect risks for cardiovascular, respiratory and metabolic diseases later in life. As part of this research paradigm, I have focused on exploring the novel roles that epigenetic changes may have in affecting susceptibility to environmental exposures such as air pollution and tobacco smoke.

What drew you the topic of environmental exposure in particular?

I have a fundamental interest in understanding how the environment affects pregnancy and the developing child.

What are your research goals?

My immediate goal is to understand the interplay between the environment and stress in pregnancy, with a focus in health disparate populations. I am studying this through the Maternal And Developmental Risks from Environmental and Social Stressors (MADRES) Center, which is an Environmental Health Disparities Center that I lead that is recruiting and following a large, prospective pregnancy cohort of lower income, predominantly Hispanic, women in Los Angeles. Through our Center research, we are asking questions about how exposures (to things like air pollutants and heavy metals) and stressors in pregnancy affect mom’s metabolic health and baby’s risk for developing obesity as a child. We are also investigating the potential signaling roles that small biological molecules may play in carrying messages from mom to baby in the womb, and whether stressors and exposures can alter these signals.

What does your research into prenatal health entail?

I lead a large team of collaborators who work together to develop the scientific questions to be asked and answered, as well as staff who recruit and follow participants, collect data and biospecimens, and manage and analyze the data. There are many moving parts as the Center is in active recruitment and follow-up of 1,000 women and their babies. The MADRES Center is also a member site of a much larger Environmental Influences on Child Health Outcomes (ECHO) program, run out of the office of the Director of the National Institutes of Health (NIH). I am also principal investigator of our local site effort as a part of ECHO. Therefore we collaborate on the local and the national levels to address questions not only about children’s metabolic health, but also perinatal/postnatal, respiratory and neurological health in response to a host of environmental exposures.

How long have you been researching prenatal and children’s health? Have you seen positive or negative progress during that time?

The MADRES Center is in its fourth year and we are in our third year as a part of ECHO; however, my own research evaluating air pollution and tobacco smoke exposures in children’s health has been ongoing over the past 12 years. Over that time, I have certainly seen progress in the field, a greater awareness that various child diseases and conditions may have contributing factors that begin as early as in the womb. I have also witnessed a greater awareness of potential biological mechanisms that might drive environmental health effects, including a growing body of evidence that epigenetic mechanisms may play a role.

How well-studied has the issue of childhood and prenatal exposure been in the past? What still needs to be done?

There is a wealth of information demonstrating that air pollution is bad for your health as an adult. There is growing awareness and evidence that it is also bad for you as a child, and even before you are born. This may be true of many other environmental exposures as well. The period of fetal development may be a particularly susceptible period of time, precisely because so much growth and development is happening. There is great potential for that growth to be skewed or perturbed by pollutants. We are just beginning to see examples of such perturbations, particularly in animal model systems in tightly controlled experimental designs. We continue to need to find evidence of either harms or benefits of various exposures in human association studies.

Why is it so important to understand the effects of our environment and pollution, and who should be concerned?

We should all be concerned about the chemicals we breathe, ingest or absorb through our skin. As humans, we are constantly bombarded with exposures to multiple chemicals — most of which we aren’t even aware of. When we identify chemicals or pollutants that seem to have negative health effects, we must do our due diligence to understand how bad they are for us, and if there are particular periods in our lives that make us uniquely vulnerable. When armed with this knowledge, we can then make informed choices with regard to our own behavior, to minimize risk to ourselves or to our children (born or unborn). And we can, as a population, seek policy changes that protect our children in the future. In the case of air pollution, these may be to lower the thresholds of national or state standards, to alter local siting requirements, etc.

What are the major challenges to research on environmental exposure?

Population-based studies are often challenged by critics for not demonstrating causation between an exposure and an outcome. We must therefore be diligent as scientists in conducting rigorous research, with replication of results to bolster conclusions. In some cases, we must press for change when evidence is suggestive even if not conclusive, to err on the side of protecting the public’s health rather that gambling with it.

What can the public do to minimize exposure to harmful substances?

Learn about the environment around you. Learn about the ingredients in the products you use, in the food that you eat. There are many resources available through which to learn. When possible, use your purchasing power to effect change — even if in very small ways.

What can public health workers do to advance the cause?

Continue to conduct rigorous research, ask questions, learn and apply that knowledge in all of your future endeavors.

— by Carolyn Barnes

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Interested in environmental health? The Master of Public Health  program at USC offers an environmental health sub-concentration that provides students with the skills and knowledge they need to make a difference. Download our Degrees and Careers Guide to read more about our education offerings and the field of public health.

Featured image: Participants pose for a picture from a MADRES Center workshop. Photo courtesy USC Environmental Health Centers.

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