The Chalkboard: Recent EPA Children’s Health Research Updates
May/June 2025
Harnessing New Approach Methods to Protect Children's Environmental Health
The field of toxicology continues to advance the technologies and approaches used to predict potential chemical hazards. Traditional methods use laboratory animals such as small rodents, zebrafish, and fathead minnows to explore the potential health risks that exposures to chemicals and other substances pose. The development of new approach methods (NAMs) that harness powerful computer modeling, robot-aided high-throughput screening mechanisms, curated cell lines, and other high-tech advances are ushering in a new generation of faster, far-less expensive chemical screening and safety tests.
Researchers are beginning to tailor NAMs to explore potential risks to the most vulnerable stages of growth and development—making them more promising for advancing children’s environmental health.
Recent examples illustrate how:
- DevTox
EPA researchers are leading the development of model platforms for conducting cell-based (as opposed to whole-animal based) assays to detect chemical risks to pregnant women, their offspring, and other susceptible populations. One such platform is DevTox, designed to rapidly identify potential hazards and characterize toxic effects during the early, critical stages of cell growth and differentiation in human development.1
Recent research evaluating the technical performance of DevTox across four different developmental assay modes is helping researchers refine it for fast, routine screening of potential developmental toxicants.2
- Assessing Chemicals Lacking Data
Agency researchers used a suite of NAMs-based approaches in a study3 screening previously studied chemicals which had little-to-no existing data for indications of endocrine, developmental, neurological, and immunosuppressive effects, all of which carry serious implications for children’s health. “This case study further enables regulatory scientists from different international purviews to utilize efficient approaches for prospective chemical management, addressing hazard and risk-based data needs, while reducing the need for animal studies,” the authors of the study conclude.
- Testing High-Throughput, High-Content Bioassays
A major driving force behind the development of NAMs is the growing need to quickly and efficiently screen chemicals to address emerging public health and ecological concerns.
Agency researchers and partners used EPA-developed high-throughput, cell-based assays to identify and contrast hazards related to a substance commonly used in car tires as a preservative (6PPD) and its degradant (6PPD-quione), the latter of which has recently been identified as the culprit in ongoing deaths of pre-spawn coho salmon following rain events in the Pacific Northwest.
Including assays based on fathead minnow and zebrafish larvae, rainbow trout gills, RNA sequencing, and mammalian cells yielded results that have implications beyond addressing immediate concerns for coho salmon. “Application of the set of high-throughput and high-content bioassays to test the bioactivity of this emerging pollutant has provided data to inform both ecological and human health assessments,” the authors of the study note.
- Chemical Signatures of Common Household Products
Researchers from EPA led a proof-of-concept study4 applying suspect screening analysis to characterize chemicals from common household products. They extracted samples from 92 products in five categories (cotton clothing, fabric upholstery, shampoo, baby soap, and silicon kitchen tools) and ran them through two-dimensional gas chromatography-high-resolution-time-of-flight/mass spectrometry. Then, they created “ingredient signatures” based on the structural and functional characteristics of the chemicals identified in the sample analysis.
The signatures derived can be used to evaluate new and existing products and could help inform exposure assessments and NAM-based bioactivity screening, ultimately leading to a better understanding of potential health risks associated with household products.
Sources
- Gamble, J. T., Hopperstad, K., & Deisenroth, C. (2022). The DevTox germ layer reporter platform: An assay adaptation of the human pluripotent stem cell test. Toxics, 10(7), 392. Read about the publication and find a download in EPA’s Science Inventory.
- Gamble, J. T., & Deisenroth, C. (2025). Profiling assay performance in the DevTox germ layer reporter platform. Current Research in Toxicology, 100223. The published research is available at: https://doi.org/10.1016/j.crtox.2025.100223.
- Friedman, P., Thomas, R. S., Wambaugh, J. F., Harrill, J. A., Judson, R. S., Shafer, T. J., ... & Sobanski, T. (2025). Integration of New Approach Methods for the Assessment of Data Poor Chemicals. Toxicological Sciences. Read the published paper: https://doi.org/10.1093/toxsci/kfaf019
- Stanfield, Z., Favela K., Yau, A., Menn, C., Edrisi, H., Philips, K. A., … & Wambaugh, J. F. (2025), Developing Chemical Signatures for Categories of Household Consumer Products Using Suspect Screening Analysis. Environmental Science & Technology 59 (2), 1354-1366. Learn more about the study and find a link to the publication on EPA's Science Inventory.
Developmental Toxicity of Disinfection Byproducts
Treating water to make it is safe for drinking requires careful management so that the cleaning agents used, such as chlorine, remove germs, but don’t lead to unhealthy levels of disinfection byproducts (DBPs) as they do their job. DBPs have also been associated with birth defects, and several are regulated by EPA.
To further explore these associations, Agency researchers recently conducted a toxicology study of DBP effects on development. To do so, they exposed pregnant rodents to DBPs and then examined pregnancy loss and eye defects in the offspring. Results illustrated relative potencies between different classes of DBPs that may be valuable for refining risk assessments of exposures to DBPs—important considerations for informing Agency actions to fulfill its mandate to safeguard the nation’s drinking water.
Source
Narotsky, M. G., Fuentes, L. S., Ola, O., Willoughby, T. L., & Lucas, K. (2025). Developmental toxicity of disinfection byproducts in F344 rats: Effects on pregnancy maintenance and eye development. Birth Defects Research, 117(1), e2427. Learn more and see a link to the published paper in EPA’s Science Inventory.
Read previous highlights in The Chalkboard archive.