Rosemarie de la Rosa tracks how childhood exposure to environmental pollutants and social stress has lifelong affect

Growing up in the Bronx,  Rosemarie de la Rosa, assistant professor at  UC Berkeley School of Public Health, noticed a high incidence of children with asthma and other diseases, compared to those living in the wealthier, less-polluted neighborhoods of New York City.

She was curious about the disparity, and wondered what the cause was. Did it stem from a difference in each neighborhood’s level of pollutants? Could there be other factors, such as poverty or additional psychosocial stressors, which made her neighbors more susceptible to chemical exposures than children growing up seven miles away in Manhattan’s swanky Upper East Side?

And if so, how could this biological impact be quantified? Such critical questions have driven de la Rosa’s career as a laboratory scientist. From her undergraduate years studying biology at M.I.T., through her graduate studies at UC Berkeley School of Public Health to her current post, de la Rosa has zeroed in on the way that childhood social stressors create susceptibility to the toxic effects of chemical pollution throughout one’s life.

“It’s personal to me,” de la Rosa said. “Having grown up in these environments and currently living in East Oakland, I really want to identify potential solutions that can eventually mitigate the effects of cumulative exposure to chemicals and psycho-social stressors.”

Discovering how stress affects child health

De la Rosa has led two recent studies toward that goal. Together, they offer intriguing theories on the individual and synergistic effects of social stressors and pollution. The data for both studies were drawn from the Pediatric Adverse Childhood Experiences Screening and Resiliency Study.

In an article published in the issue February/March 2023 of Psychosomatic Medicine, de La Rosa’s team reported that higher allostatic load —wear and tear on the body from chronic stress—was associated with a greater number of reported adversities and worse child health.

Previous studies had shown that higher allostatic load predicts adult morbidity and mortality as well as poorer health outcomes and behavioral problems in children. De la Rosa focused solely on children.

“It is important to ascertain whether and when allostatic load biomarker indications associate with disease in childhood,” the scientists wrote. “Our findings provide initial evidence in this realm, showing that higher allostatic load was associated with worse general health in children, as measured by the PROMIS PGH-7 score,” which is an internationally accepted self-reported measure of children’s overall health.

De la Rosa and her colleagues screened 207 children, mostly from the San Francisco Bay Area, with a research tool called the Pediatric Adverse Childhood Experiences and Related Life Events Screener, known as PEARLS. This tool is currently being used across the state of California to screen children ages 0-19 years for exposure to ACEs and toxic stress.

The researchers had parents complete the PEARLS questionnaire about their child, which captures experiences of abuse, neglect, household challenges, and related life events. It is 17 questions in all. The researchers also obtained biological data for the participants across four physiological systems: cardiac, metabolic, inflammatory, and neurologic. Most of the participants were non-Hispanic Black and/or low-income children.

“The interesting piece was that we saw that a relationship with caregiver mental illness in the home was associated with increased allostatic load in children,” de la Rosa said. “We don’t know how it’s working, but we are expanding on that work to understand how the potentially child and caregiver relationship may influence allostatic load.”

Persuading the families to participate—and to stay enrolled in the study—was not easy.

“We invest a lot of effort and time in making sure that the research team and the providers involved represent a lot of the demographics of the population. You have to establish trust,” she said.

Early adversity may lead to shorter life span

A new study by de La Rosa and her research team, “Associations Between Early-Life Adversity, Ambient Air Pollution, and Telomere Length in Children,” was published today, also in Psychosomatic Medicine.

This report examined the associations and interaction between early-life adversity and exposure to residential ambient air pollution, specifically fine particulate matter. (Common outdoor sources of fine particulate matter include vehicle exhaust, burning wood and gas, and fires. Common indoor sources are cigarette smoke, fireplaces, and fuel-burning space heaters.) Fine particulate matter is so small that it can be inhaled into the lungs.

The work builds on a 2022 paper that de la Rosa co-authored on the impact of structural racism on asthma and dermatitis, with Dr. Mahasin Mujahid, professor of epidemiology and Lillian E. I. and Dudley J. Aldous Chair at UC Berkeley School of Public Health, and two faculty members at UCSF. In this paper, the researchers developed a conceptual framework for how environmental exposure and psychosocial stressors, such as ambient air pollution and childhood adversity, are concentrated in historically marginalized communities as a consequence of structural racism, becoming biologically embedded and contributing to racial and ethnic asthma disparities.

Austin Le, who was a master’s student at BPH while contributing to this work, is de la Rosa’s co-first author. Le is now a medical student at the University of Illinois.

In the new study, de la Rosa’s team suggests that physical and social environments become biologically embedded over the life course, through alterations in biological processes, including cellular aging. They quantify the effects of these exposures by measuring the length of telomeres, the protective caps at the end of chromosomes and a biomarker of the cellular aging process. Researchers measured telomere length using DNA obtained from a cheek swab for each participant.

“One hypothesis of how stress may influence the body is through accelerated aging, “ de la Rosa said, “Shorter telomeres have also been associated with increased risk of age-related diseases, such as cardiovascular and chronic obstructive pulmonary disease.”

The researchers studied 197 participants receiving care at a clinic at Benioff Children’s Hospital Oakland, where 95 percent of the patients are in state-sponsored medicaid, mostly non-hispanic black children.

The results suggest that adverse social context factors may accelerate the association between chronic fine particulate matter exposure on telomere shortening during childhood. De la Rosa says the researchers are currently following the participants for five years to see if these associations persist and to examine relationships with health outcomes.

“This research is built on experiences I’ve had,” de la Rosa said. “It goes back to knowing my own family had to navigate some of the challenges around childhood adversity. I had a lot of positive role models in my life to buffer that, but the question is what happens when we don’t have those support systems in place? How do we create environments where all children can thrive equitably?”