The HUMIS-NOMIC birth cohorts were set up in 2003 to study environmental toxicants in breast milk, maternal and infant gut microbiota development and child health. My work to date has focussed on prenatal and postnatal exposure to persistant organic pollutants such as PCBs, organochlorine pesticides, and dioxins, and the association with infant growth and later childhood obesity. I am also involved in a number of other studies investigating these exposures ADHD and neurodevelopmental outcomes. I am currently study mixtures of toxicants in breastmilk and the impact on infant gut microbiota. In addition to working with these Norwegian data, I have worked on EU projects to harmonise data from a number of European cohort studies and conduct pooled analyses.