Characterization of childhood exposure to environmental contaminants using stool in a semi-urban middle-class cohort from eastern Canada

Children are exposed to various environmental organic and inorganic contaminants with effects on health outcomes still largely unknown. Many matrices (e.g., blood, urine, nail, hair) have been used to characterize exposure to organic and inorganic contaminants. The sampling of feces presents several advantages; it is non-invasive and provides a direct evaluation of the gut microbiome exposure to contaminants. The gut microbiome is a key factor in neurological development through the brain-gut axis. Its composition and disturbances can affect the neurodevelopment of children. Characterization of children exposure to contaminants is often performed on vulnerable populations (e.g., from developing countries, low-income neighborhoods, and large urban centers). Data on the exposure of children from middle-class, semi-urban, and mid-size populations to contaminants is scarce despite representing a significant fraction of the population in North America. In this study, 73 organics compounds from different chemical classes and 22 elements were analyzed in 6 years old (n = 84) and 10 years old (n = 119) children's feces from a middle-class, semi-urban, mid-size population cohort from Eastern Canada. Results show that 67 out of 73 targeted organics compounds and all elements were at least detected in one child's feces. Only caffeine (97% & 80%) and acetaminophen (28% & 48%) were detected in more than 25% of the children's feces, whereas all elements besides titanium were detected in more than 50% of the children.