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 out-comes 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 micro -biome 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.

Automated summary

Children are frequently exposed to various environmental contaminants, and the effects on health outcomes are still not well understood. Fecal samples provide a non-invasive and direct assessment of gut microbiome exposure to contaminants. This study analyzed organic compounds and elements in the feces of middle-class, semi-urban children in Eastern Canada, and found that most targeted compounds and elements were detected, with caffeine and acetaminophen being the most common substances.