Researchers from multiple US institutions analyzed urine samples from 201 toddlers aged 2 to 4 years to identify which environmental chemicals children are exposed to daily. They tested for 111 chemicals in total and found evidence of 96 different ones in the children's bodies.
The study, published in Environmental Science & Technology, was part of a larger US government-funded program examining how early environmental exposures affect child health and development. While the research was conducted in the United States across four states, the chemicals tested are commonly found in household products and food used worldwide, including Singapore.
Everyday activities expose toddlers to multiple chemicals at once
Toddlers encounter these chemicals through normal daily routines: eating and drinking, breathing indoor and outdoor air, and touching surfaces. Common sources include pesticides (from food and gardens), plasticizers (chemicals in plastics and personal care products), and flame retardants (used in furniture and textiles).
Young children are particularly vulnerable because they frequently put their hands and objects in their mouths, play close to the ground, and have smaller body weight relative to their intake — meaning chemical concentrations affect them more significantly than adults.
Some chemicals are higher in toddlers than in their mothers
The researchers compared chemicals detected in toddlers' urine with samples from their mothers during pregnancy. They found children had notably higher levels of certain chemicals, including two types of phthalates (plasticizers), bisphenol S (a BPA replacement), and pesticide markers.
This increase suggests toddlers are accumulating additional chemical exposure after birth through their environment and behaviours, beyond what they were exposed to in the womb.
Many chemicals remain understudied and unregulated
The researchers emphasize that many of the 96 chemicals detected are not routinely monitored by health authorities. Previous research has linked early exposure to pesticides, plasticizers, and flame retardants to developmental delays, hormone disruption, and immune problems — but long-term effects of this particular combination of chemicals in toddlers remain unknown.
The study has a key limitation: it involved only 201 children from four US states, so results may not apply uniformly to all populations or regions, including Singapore.
Steps to reduce your toddler's chemical exposure
- Wash your toddler's hands frequently, especially before eating and after playing outdoors or on floors.
- Rinse fresh produce under running water before serving, as pesticide residues are common on some fruits and vegetables.
- Choose furniture and textiles labelled as flame-retardant-free where possible, and avoid plastic items marked with recycling codes 3 or 7 (which may contain problematic plasticizers).