Children are especially vulnerable to environmental exposures, as their bodily systems are still developing. They eat more food, drink more fluids, and breathe more air in proportion to their body weight than adults. Additionally, children's size and weight may make their bodies more vulnerable to harmful exposures, and their behavior patterns may increase overall risk.
The National Academies report, "Pesticides in the Diets of Infants and Children," highlighted that existing regulatory approaches did not adequately protect infants and children. The report led to several actions by Congress, the Executive Branch, and the Environmental Protection Agency (EPA) designed to protect children's health from environmental exposures. In particular, the EPA created its Office of Children's Health Protection (OCHP), which collaborates with other agency offices to ensure EPA actions consider the heightened risks faced by children, identify research gaps, and promote outreach efforts.
To celebrate OCHP's 25th anniversary, EPA contracted the National Academies to plan and host a workshop to explore new research that may help to shape future decisions about protecting children from environmental hazards.
Janet McCabe, deputy administrator of the EPA, said the agency's vision is that all children, especially those in underserved communities, can live, learn, and play free from environmental exposures that contribute to harmful health effects. For example, EPA is working to remove 100 percent of lead service lines across the country, clean up Superfund and Brownfield sites, and replace diesel buses with electric school buses—lowering children's exposure to harmful exhaust. EPA is also reconsidering the 2020 National Ambient Air Quality Standards for ozone and particulate matter, two pollutants linked to childhood asthma. The agency also ended chlorpyrifos use on food, protecting children and farm workers from the pesticide.
Philip Landrigan, professor at Boston College and chair of the landmark National Academies report, "Pesticides in the Diets of Infants and Children," delivered the keynote presentation for the workshop. He identified three existential threats to children's environmental health: 1) climate change, 2) air pollution, and 3) chemical pollution, including pesticides and plastics. Climate change impacts children's health through adverse pregnancy outcomes, heat-related illness, allergic diseases, cardiovascular disease, water shortages, infectious diseases, malnutrition and famine, forced migration, and war. Diseases caused in part by air pollution include cardiovascular disease, stroke, chronic obstructive pulmonary disease, lung cancer, and diabetes in adults. In children, air pollution is responsible for premature birth, low birthweight, stillbirth, asthma, and impaired lung development. Chemical pollution and plastics pose substantial risks to children and are linked with numerous health effects, such as neurodevelopmental disorders, reduced fertility, birth defects, and cancers.
Landrigan highlighted several strategies for improving children’s environmental health. Clinical and epidemiologic research could quantify the impact of climate disasters such as wildfires, storms, and floods. Non-governmental organizations at the national, state, and local level can incentivize the use the renewable energy, improve the power grid, and end federal subsidies for the fossil fuel industry. Addressing the challenge of air pollution is hindered by a lack of granular data on where the pollution is occurring; fine-grained, highly localized maps can be created to identify the most impacted communities. More epidemiologic studies that measure exposures to chemical and plastic pollution and health outcomes across the life course could help identify etiologic associations between chemicals and health. Laboratory methods such as high-speed, multi-chemical analyses to measure human exposure to chemicals would improve epidemiologic studies; and more high-throughput toxicological studies would allow for a quicker understanding of the toxicities of chemicals and mixtures.
Informing Decision Making
The session began with presentations from Tracey Woodruff, University of California—San Francisco (UCSF), who discussed why children's environmental health continues to be of critical concern. Aaron Bernstein, Harvard University, discussed the impact of climate change on children's environmental health and his research efforts to improve civic engagement on the topic. Zhiwei Xu, University of Queensland, discussed the impact of heatwaves on children's environmental health. The session closed with a panel discussion addressing critical gaps that hinder progress in environmental health policy. Brenda Eskenazi, University of California—Berkley; Mark Miller, California EPA; and Thomas Burke, Johns Hopkins University, participated. The entire session was moderated by Mona Hanna-Attisha, Michigan State University and Hurley Children's Hospital Pediatric Public Health.
Key takeaways include:
Exposures to some chemicals that may influence children's health are increasing. The best available science is needed to apply upstream approaches to preventing harmful exposures (Woodruff).
In the U.S., environmental health concerns are not at the top of parents' minds. A change in mindset and improved awareness about the impacts of climate on children's health are necessary to increase civic engagement on the issues and take action (Bernstein).
Action is needed on climate and heat adaptation to protect susceptible children from heatwaves because they are associated with lifelong health impacts such as preterm birth, low birthweight, and infant hospitalization (Xu).
More translation of scientific findings other than traditional media (i.e., animated videos, advertisements, and other consumable media) (Xu).
It is challenging to assess exposures during critical developmental windows, especially for exposures that may have short half-lives; however, exposure assessments are needed to improve the understanding of exposures for pregnant women and children (Eskenazi).
Some standard practices used to account for child vulnerability (such as an adjustment factor of 10) are unlikely to account for all the unique vulnerabilities of children. In addition, adolescence is understudied as a susceptible period (Miller).
Environmental injustice cannot be addressed with the current exposure data; more granular data for air monitoring and other exposures are needed to identify areas of noncompliance (Burke).
Environmental Influences on Children's Health Across the Lifespan and Generations
The session included a series of presentations from experts on environmental influences on children's health and development. Paul Juarez, Meharry Medical College, discussed the public health exposome and health equity. Frederica Perera, Columbia Center for Children's Environmental Health, discussed biomarkers to air pollution and children's health and development. Niels Erik Skakkebæk, Rigshospitalet and the University of Copenhagen, presented the relationship between pollution exposure and chronic disorders of the male reproductive system. Kelly Ferguson, National Institute of Environmental Health Sciences, described the importance of disentangling heterogeneous health outcomes to improve research evaluating chemical exposures during pregnancy. Manish Arora, Icahn School of Medicine at Mount Sinai, presented on prenatal exposures as markers for Autism risk. The session was moderated by Germaine Buck Louis, former dean of the George Mason College of Public Health, who chaired the planning committee.
Key takeaways include:
There is a need for a human exposome project, like the human genome project, which would allow investigators from different fields to standardize the different exposure measures to improve data sharing (Juarez).
Fossil fuel use harms children's health by leading to climate change and increased exposure to air pollution (Perera).
Male infertility is increasing globally and may be related to endocrine-disrupting chemical exposure during fetal development (Skakkebæk).
It is important to disentangle heterogeneous health outcomes to ensure studies can demonstrate the effects of chemical exposures. It is also essential to begin new cohorts that measure chemicals with increasing use, such as terephthalates, to identify potential associated health effects (Ferguson).
Understanding environmental exposures is a missing piece in adopting precision medicine. Yes, exposures are dynamic, so to fully adopt a precision medicine framework, the question of how exposures change throughout the lifespan needs to be considered (Arora).
Harnessing Data for Decision Making
Chirag Patel, Harvard Medical School, opened by presenting strategies for using data to protect public health. Workshop participants then split up into breakout sessions to discuss alternative animal models (led by Robyn Tanguay, Oregon State University), cumulative risk assessment (led by Linda Birnbaum, National Institute of Environmental Health Sciences, retired), and biomarkers of exposure (led by Marie Fortin, Jazz Pharmaceuticals). Darryl B. Hood, Ohio State University, moderated the entire session.
Key takeaways from the session include:
The data and samples available in large biobanks can provide a resource for understanding the impacts of environmental exposures on health (Patel).
Key takeaways from breakout session discussions:
New toxicology methods, or alternative animal models, offer much promise. For example, the new assays can identify biologically active and biologically accumulative chemicals, which could be enough to warrant policy action (Tanguay).
Many scientists recognize the importance of considering cumulative risks, but risk assessments rarely use that science. A lack of perfect data needs to become a limitation to be recognized, not a reason not to act. (Birnbaum).
Exposomics biomonitoring data is rich and can be used in large cohorts to link exposures and disease, but we need to increase diversity in the studied populations and encourage the use of big data in decision-making (Fortin).
Balancing Prevention and Uncertainty
The final day included two sessions. Nsedu Obot Witherspoon, Children's Environmental Health Network, moderated the first session regarding case examples of science informing policy and public health action. Stephanie Yellen, Minnesota Department of Health; Maida Galvez, New York State Children's Environmental Health Centers; and Shirlee Tan, Public Health — Seattle & King County, presented examples from their respective states. Heather Patisaul, North Carolina State University, moderated the second session, a panel discussion on strategies for acting despite uncertainty. David Levine, American Sustainable Business Council; Alison Connolly, University of Galway (Ireland); and Wendy E. Wagner, University of Texas School of Law, served as panelists. Nsedu Obot Witherspoon provided closing remarks. The workshop ended with a video message from Mari Copeny, Little Miss Flint.
Key takeaways include:
In New York State, clinicians and environmental health professionals created a network that brings environmental health resources to pediatric care: the New York State Children's Environmental Health Centers (NYSCHECK). All seven NYSCHECK centers have implemented health e-screenings in clinical settings to connect families to actionable prescriptions for prevention. They also distribute Healthy Home kits to address common environmental health concerns such as lead, secondhand smoke, mold, and radon. Other states could leverage regional resources to see where children's environmental health needs can be better met (Galvez).
Public Health — Seattle & King County has reduced harmful indoor air and flame-retardant exposures in childcare centers by providing centers with flame-retardant-free nap mats or nap mat covers and air cleaners (Tan).
Minnesota successfully coordinated agencies to respond to cases of lead take-home exposures from a fish sinker manufacturing facility (Yendell).
Evidence is needed to drive policy, but manufacturers benefit from ignorance because the burden of proof is on regulators to determine that a chemical causes harm (Wagner).
European groups are working on harmonizing biomonitoring and hazard identification data for policymaking (Connolly).
Business is not a monolith, and some businesses want to be part of decisions that may protect children from environmental harm (Levine).
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The National Academies' Board on Population Health and Public Health Practice, Board on Environmental Studies and Toxicology, and Board on Children Youth and Families convened a workshop in August 2022 to explore the impact of specific environmental exposures in utero, infancy, early childhood, and adolescence. Experts in epidemiology, toxicology, dose-response methodology, and exposure science explored gaps in knowledge around vulnerabilities to environmental hazards and opportunities to inform public policy moving forward.
This Proceedings document summarizes meaningful discussions held during the virtual event and describes potential research priorities and ways the Environmental Protection Agency (EPA) can incorporate new research methods into its risk assessments and policy decisions.