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Introduction
Children are especially vulnerable to environmental exposures. 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. Children’s size and weight may make their bodies more vulnerable to harmful exposures, and their behavior patterns may increase their level of exposure (Landigran and Etzel, 2013; NRC and IOM, 2004).
The National Academies report, Pesticides in the Diets of Infants and Children (NRC, 1993), highlighted that existing regulatory approaches did not adequately protect infants and children and led to federal actions.
- In 1995, the Environmental Protection Agency (EPA) created its Policy on Evaluating Health Risks to Children, which directed it to explicitly and consistently take into account environmental health risks to infants and children in all risk characterizations and public health standards set for the United States (EPA, 1995).
- In 1996, the Food Quality Protection Act (FQPA) was passed; it amended the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal Food Drug and Cosmetic Act (FFDCA) by updating and adding important requirements to protect children’s health (EPA, 2016; Firestone et al., 2016).
- In 1997, President Clinton signed an executive order establishing requirements for children’s health protection (Executive Office of the President, 1997). It created the “President’s Task Force on Environmental Health Risks and Safety Risks to Children” and required many federal agencies to assign a high priority to health
and safety risks to children, improve coordination of research priorities on children’s health, and ensure that federal standards take into account special risks to children.
Several environmental regulations contain children’s health provisions, such as the Clean Air Act, as amended in 1990, and the Safe Drinking Water Act, as amended in 1996.
In response to Clinton’s executive order (Executive Office of the President, 1997), the EPA created its Office of Children’s Health Protection (OCHP) and provided explicit and dedicated resources to protect children from environmental hazards. OCHP directs and collaborates with other agency offices to ensure that the EPA actions consider the heightened risks faced by children, identify research gaps, and promote health outreach efforts (Firestone et al., 2007, 2016). Since forming that office, the EPA has developed a series of guidance documents that aim to ensure risk assessments consider children properly. Child-specific guidance documents include Guidance on Selecting Age Groups for Monitoring and Assessing Childhood Exposures to Environmental Contaminants, Child-Specific Exposure Factors Handbook, Supplemental Guidance for Assessing Susceptibility from Early-Life Exposure to Carcinogens, and A Framework for Assessing Health Risk of Environmental Exposures to Children (EPA, 2002, 2005a, 2005b, 2006a; Firestone et al., 2016).
As part of a celebration of the EPA’s Office of Children’s Health Protection’s 25th anniversary, the EPA contracted the National Academies to plan and host a workshop to explore new research that can offer opportunities for future decisions that protect children from environmental hazards (see Box 1-1). This work is not a product of the U.S. Government or the U.S. Environmental Protection Agency. The views expressed by the workshop participants are their own and do not necessarily represent those of the U.S. Government or the EPA. This effort is important because EPA can improve children’s health protection with new authority from the Frank R. Lautenberg Chemical Safety for the 21st Century Act (2016), which amends the Toxic Substances Control Act (1976) and an updated 2021 Policy on Children’s Health (EPA, 2021).
OPENING REMARKS
The workshop began with remarks from Janet McCabe, Deputy Administrator of the EPA, and Philip Landrigan of Boston College, who chaired the landmark National Academies report, Pesticides in the Diets of Infants and Children (NRC, 1993).
Children’s Environmental Health at the EPA1
McCabe highlighted the agency’s recent accomplishments and future goals. The EPA’s role in protecting children’s health includes implementing environmental laws, setting standards that protect public health, and advancing and funding research that can develop the science on which the EPA’s policies and regulations are based. The EPA’s strategic plan sets a crosscutting goal of recognizing vulnerabilities to environmental exposures and strengthening its commitment to protecting human health (EPA, 2022b). The new strategic plan and the EPA’s updated policy on children’s health will help the EPA move toward the vision that all children, especially those in underserved communities, thrive by living,
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1 This section is based on a presentation by Janet McCabe, deputy administrator, Environmental Protection Agency.
learning, and playing free from environmental exposures that contribute to harmful health effects. For example, the EPA is using funding from the new infrastructure law 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 vehicle exhaust. The EPA is also reconsidering the 2020 National Ambient Air Quality Standards for ozone and particulate matter, two pollutants linked to childhood asthma. The EPA also recently ended chlorpyrifos use on food, protecting children and farm workers from the pesticide.
McCabe highlighted that the EPA is committed to protecting children’s health equity and addressing decades of systemic neglect and inadequate protection of communities of color. The EPA will consider these issues as allowed and authorized by law for enforcement decisions, research support, and all work with state, local, and tribal partners. McCabe then emphasized that “no government agency can make good policy without good science and data to base it on,” describing the need for this workshop.
Critical Data Gaps and the Promise of New Methods2
Landrigan, who provided the keynote presentation for the workshop, cited three existential threats to U.S. children’s environmental health: (1) climate change, (2) air pollution, and (3) chemical pollution, including pesticides and plastics. For each threat, a key question needs to be addressed: “What are the key data gaps and the strategic opportunities for new research and science-based advocacy that can make a difference for children’s health and save lives?”
Climate Change
Climate change is damaging children’s health. The Earth’s mean surface air temperature has increased by about 1.04° C (1.87° F) since 1880.3 The main driver is fuel combustion, which increases concentrations of carbon dioxide (CO2) and other greenhouse gases in the atmosphere (IPCC, 2018). CO2 levels have risen to a level not seen since the age of the dinosaurs (Foster et al., 2017). Climate change has significant ecologic consequences: wildfires, drought, more frequent violent storms, melting glaciers, sea surface rise, coastal flooding, and expanded ranges and
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2 This section is based on a presentation by Philip Landrigan, professor, Boston College.
3https://www.climate.gov/news-features/understanding-climate/climate-change-global-temperature#:~:text=Averaged%20across%20land%20and%20ocean,10%20warmest%20years%20on%20record (accessed December 29, 2022).
longer seasons for vector-borne diseases (IPCC, 2018). It also directly and indirectly 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 (Perera and Nadeau, 2022).
Landrigan offered several research suggestions to track the impact of climate change on children’s health. In the short term, researchers could conduct clinical and epidemiological studies in the aftermath of climate disasters, such as wildfires, storms, and floods, to quantify the impact of the events on children’s health. Federal agencies such as the CDC would need to have multidisciplinary teams of investigators trained and available to respond to disasters if such studies are to be undertaken. Multi-year ecologic studies would help monitor long-term climate impacts such as drought, food and water shortages, vector-borne diseases, and migration and conflict. These studies could define populations at risk on a highly localized, fine-grained scale. The disease burden due to climate change and its consequences could be estimated in cooperation with the Institute for Health Metrics and Evaluation at the University of Washington.
Finally, Landrigan urged non-governmental organizations to work at the national, state, and local levels and build partnerships with diverse groups. At the national level, organizations such as the Physicians for Social Responsibility and the American Academy of Pediatrics could help promote national policies by urging legislative or regulatory agencies that incentivize the use of renewable energy, building out the power grid, and ending federal subsidies and tax breaks for the fossil fuel industry. Local-level actions that could improve children’s health include closing fossil fuel–fired power plants, blocking the construction of gas and oil pipelines, forbidding the use of natural gas heat and appliances in new construction, providing tax breaks and subsidies for wind and solar, requiring operators of electric power grids to favor renewable energy, converting state and city vehicle fleets to hybrid or all-electric, expanding and enhancing rapid transit, and building regional high-speed, electric rail systems.
Air Pollution
Air pollution is primarily caused by fossil fuel combustion (EPA, 2022a) and is thus closely linked to climate change. It is responsible for 6.7 million (95 percent CI: 5.9–7.5 million) deaths globally in 2019, with the overwhelming majority in low- and middle-income countries. In the United States, it is responsible for 197,000 deaths annually (95 percent CI: 183,000–214,000) (Landrigan et al., 2022). 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 (Buka et al., 2006; Gauderman et al., 2015; Goldizen et al., 2016; Landrigan et al., 2022).
Research suggestions to address air pollution include identifying and quantifying emissions from sources at the state and local levels for both particulate matter and toxics. Fine-grained, highly localized maps could be created of contaminant levels, and the health consequences could be better quantified, especially at the local level. Additionally, Landrigan highlighted the importance of documenting the economic costs of air pollution.
Landrigan said that environmentalists could emphasize that virtually all actions to mitigate climate change will also reduce the health impacts of air pollution, creating a double benefit for children’s health. He suggested that advocates could work individually and through national organizations to urge the EPA to reduce the PM2.5 air pollution standard from 12µg/M3 to at least 5µg/M3 (the World Health Organization air quality guideline).4
Chemical Pollution
Landrigan then turned to probably the “biggest, most complex, and least studied environmental issue” that influences child health and development, chemical pollution, which is a wicked problem5 by any standard. More than 350,000 chemicals and chemical mixtures have been invented since 1950, and these are novel materials that never existed on earth until humans created them (Persson et al., 2022) (see Figure 1-1). Most chemicals and plastics are from fossil fuels (NASEM, 2022b; Tickner et al., 2021). The global annual plastic production has grown from 1.7 million metric tons in the 1950s to more than 400 million metric tons today (see Figure 1-2). Plastic is not just an inert polymer. Plastic is a matrix that contains multiple chemical additives, some of which are highly toxic, such as phthalates, bisphenol A, brominated flame-retardants, per- and polyfluoroalkyl substances (PFAS), etc. The non-polymer chemical can amount to as much as 50 percent of the weight of plastic (Landrigan et al., 2020). The recent growth in plastic production, especially the increase in single-use plastic, is “very deliberate.” While the market for fossil
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4https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health (accessed January 17, 2023).
5 Wicked problems have been described as problems that “exist on various spatial scales that unfold over long temporal scales and have possible global implications. They are difficult to define, unstable, and socially complex; have no clear or single solution or end point; and extend beyond the understanding of one discipline or responsibility of one organization” (NRC, 2012).
SOURCES: Presented by Phil Landrigan on August 1, 2022; created from data in Landrigan et al., 2020.
SOURCES: Presented by Phil Landrigan on August 1, 2022; created from data in Our World in Data (https://ourworldindata.org/plastic-pollution [accessed December 29, 2022]) Landrigan et al., 2020.
fuels is expected to decline slowly, the fossil fuel industry has extracted a great deal of oil and gas. As a result, the oil and gas industry is planning to pivot to chemical and plastic production by building cracking plants that turn natural gas into plastic feedstock to make up for the projected losses in profit.
Chemicals and plastic pollution are ubiquitous in the environment, from the high Arctic to the deep oceans (Landrigan et al., 2020; Persson et al., 2022). Plastics sink into the oceans, often in the form of microplastics, where they can be consumed by animals and enter the human food chain, exposing people to polymer plastic and related chemicals (Landrigan et al., 2020). Human exposure to anthropogenic chemicals is nearly universal, including among pregnant women and children (Woodruff et al., 2011). Environmental injustice becomes an issue as exposures are disproportionately heavy in poor and minority communities (Johnston and Cushing, 2020). The most stunning fact, according to Landrigan, is that the “vast majority, 75–80 percent, of chemicals in commerce have never been tested for safety or toxicity. They’ve been released to the marketplace, and the chemical industry waits for the Environmental Protection Agency, the National Institute of Environmental Health Sciences, or other agencies of the government to find harm years later after millions of people have been exposed.”
Chemical pollution is concerning because it poses substantial risks to children. Lead, mercury, polychlorinated biphenyls (PCBs), organophosphate pesticides, and brominated flame retardants are all associated with neurodevelopmental disorders in children. Pesticide exposures reduce fertility. Phthalates are associated with birth defects of the male reproductive organs and neurodevelopmental delays (NASEM, 2017; NRC, 2008). Prenatal exposure to dichloro-diphenyl-trichloroethane (DDT) is associated with breast cancer (Cohn et al., 2007). PFAS exposures are linked to immune dysfunction and problems with fetal growth (NASEM, 2022a). To Landrigan, “the big unanswered question that haunts all of us in this field is what other associations may exist between disease in children and untested chemicals.”
Landrigan offered research suggestions to address chemical pollution. First, prospective, multi-year birth cohort epidemiologic studies are needed to discover etiologic associations. Second, cohort studies could include harmonized metrics of both exposure and outcome measures to allow for improved meta-analyses. Finally, Landrigan emphasized the need to continue developing high-speed, multi-chemical analyses to measure human exposure to chemicals and high-throughput toxicological studies to allow for a quicker understanding of chemical toxicities.
Landrigan suggested that environmentalists push for a more precautionary approach to chemical policy. He said, “key elements of the
Precautionary Principle need to be incorporated into law in this country if we are to protect the health of America’s Children.” Landrigan added that amending the Toxic Substances Control Act (TSCA) was a step in the right direction, but it was not enough. A UN High Commission on Plastics and Chemical Pollution, analogous to the Intergovernmental Panel on Climate Change, is also sorely needed.
Successes and Thoughts for the Future
The good news, according to Landrigan, is that diseases in children caused by climate change and pollution can be prevented. The essential ingredients are scientific discovery, scientists’ willingness to translate science into policy, and government officials’ readiness to act on the science.
The environmental movement has had numerous successes. For example, banning DDT, removing lead from gasoline, and controlling air pollution in the United States. The Boston Harbor and the Chesapeake Bay are cleaner. Children’s exposures to multiple highly toxic pesticides were reduced under the FQPA of 1996, in-home use of chlorpyrifos was eliminated (Whyatt et al., 2002), and the stratospheric ozone layer has been preserved through the United Nations’ Montreal Protocol (AP, 2022).
Landrigan also noted, “we’ve observed the health and economic benefits of environmental policy successes. As lead use in gasoline declined, blood lead levels also declined, and the prevalence of childhood lead poisoning plummeted.” Pollution prevention is highly cost-effective due to saving lives, preventing disease, and reducing health care costs. Every dollar invested since 1970 in air pollution control has yielded an estimated economic return of $30 (EPA, 2011a). This economic return is mainly due to reduced expenditures for pollution-related diseases and the increased economic productivity of a healthier, longer-lived population. Removing lead from gasoline increased economic productivity by enhancing children’s cognitive function and creativity—children with lower lead exposures are more intelligent and creative and have increased lifetime earnings. Clean-ups of polluted bays and harbors have restored commercial fisheries, increased tourism, and enhanced the economic value of coastal lands.
ORGANIZATION OF THE WORKSHOP
An independent planning committee of the National Academies organized the virtual workshop in accordance with the National Academies procedures. Elizabeth Boyle and Alexandra McKay have prepared these workshop proceedings as a factual summary of what occurred at the workshop, and the National Academies does not endorse or verify
the statements. The project webpage provides a recording of the workshop and the presentation slides.6 The first session was the introductory remarks. Session 2 offered discussions about informing decision making, the state of the science, and critical gaps (Chapter 2). Session 3 covered environmental influences across the life-span and future generations (Chapter 3). Session 4 discussed harnessing data for decision making and included several breakout sessions (Chapter 4). Session 5 included case examples of science informing policy, and Session 6 discussed balancing prevention and uncertainty (Chapter 5). These proceedings are organized in order of presentation with additional synthesis across sessions when relevant. Appendixes A and B include the workshop agenda, and the biosketches of the speakers and discussants, respectively.
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6https://www.nationalacademies.org/our-work/childrens-environmental-health-a-workshop-on-future-priorities-for-environmental-health-sciences.
