A groundbreaking study finds that the bodies of modern toddlers have become living archives of chemical exposure, recording a story we are just beginning to understand.
Published: March 2025
Imagine being able to read the story of a child's environmental exposures through the very biological fabric of their body. This is the promise of chemical anthropology, an emerging scientific frontier that deciphers the complex relationship between human biology and the synthetic chemical environment we've created.
Studies ancient bones and artifacts to understand human history and evolution.
Investigates the chemical fingerprints left on and in us by modern life.
Researchers recently demonstrated this by analyzing medieval skeletons, where chemical signatures in teeth revealed centuries-old evidence of childhood malnutrition and famine 7 .
Today, this approach has taken on new urgency as scientists investigate a different kind of exposure: the synthetic chemicals that have become ubiquitous in modern environments.
Children are not simply small adults when it comes to chemical exposure. Their developing organs and metabolic systems, combined with specific behaviors, make them particularly vulnerable 3 .
"Early childhood is a critical window for brain and body development. Many of these chemicals are known or suspected to interfere with hormones, brain development and immune function."
To understand how chemical anthropologists are uncovering these disturbing patterns, let's examine the 2025 UC Davis study in detail, which exemplifies the methods and findings of this emerging field.
Children Studied
Years Old
Chemicals Tested
The research was conducted through the Environmental influences on Child Health Outcomes (ECHO) Program, a NIH-supported initiative that combines data from pregnancy and pediatric cohorts across the United States 1 4 .
The findings revealed both the sheer extent of chemical exposure and important patterns about who carries the highest burdens.
48
Chemicals in over half of children
34
Chemicals in over 90% of children
9
Chemicals not tracked in national surveys
Levels of triclosan, parabens, PAHs, and most phthalates have decreased over the years samples were collected (2010-2021) 1 4 .
These decreases have often been offset by increases in replacement chemicals such as the alternative plasticizer DINCH and emerging pesticides 1 .
Perhaps most alarmingly, the study found that children often had higher levels of several chemicals than their mothers did during pregnancy, including:
A phenomenon where banned chemicals are replaced with similar compounds that may pose similar health risks 3 .
The discoveries of chemical anthropology would be merely academic if not for their profound health implications. Research increasingly links early chemical exposures to concerning developmental trends.
A separate 2025 study from McMaster University identified specific blood metabolites linked to early childhood development, with some toxins appearing to interfere with cognitive milestones 5 .
The researchers found that certain uremic toxins—byproducts of metabolism and microbial fermentation—were inversely associated with developmental outcomes, potentially contributing to inflammation and developmental delays 5 .
Since the 1970s, despite overall improvements in healthcare, concerning trends have emerged 9 :
"The evidence is so overwhelming and the effects of manufactured chemicals are so disruptive for children, that inaction is no longer an option."
While the findings of chemical anthropology are concerning, they also point toward solutions. The 2025 UC Davis study noted some encouraging trends, suggesting that awareness and regulation can make a difference 1 4 .
Parents can take practical steps to reduce their children's chemical exposures:
Look for "phthalate-free," "paraben-free," and "fragrance-free" labels 4 .
Steer clear of plastics labeled #3, #6, and #7, which may contain BPA or similar chemicals 4 .
Especially before eating, to remove chemical residues 1 .
Use HEPA filters when possible to reduce indoor air pollutants 4 .
Use a damp cloth to reduce dust that may contain chemical residues 4 .
On a broader scale, many scientists are calling for a paradigm shift in chemical regulation 9 .
Rather than assuming chemicals are innocent until proven guilty, advocates call for a precautionary approach that requires thorough safety testing before chemicals enter consumer markets 9 .
"As a society, we've slowly just been neglecting this. The clinical and public health community and the government has failed them."
Chemical anthropology represents more than just a new scientific specialty—it's a vital lens through which to understand the unintended consequences of our modern chemical environment on the most vulnerable among us.
By reading the biological records preserved in children's bodies, scientists are documenting a story that demands attention. The chemical signatures they're finding are not merely academic curiosities; they are potential predictors of developmental trajectories and lifelong health challenges.
The message from this emerging science is clear: if we want to protect our children's future, we must become better readers of their present chemical exposures. As we move forward, chemical anthropology will play an increasingly crucial role in shaping healthier environments for the next generation.
For further reading on this topic, explore the research from the Environmental influences on Child Health Outcomes (ECHO) Program and the UC Davis Environmental Health Sciences Center.