Despite being important in a public health perspective, there is little knowledge about the harmful effects of environmental contaminants on brain development and cognitive functions, or the risk of neurological disorders in children such as ADHD, autism, cerebral palsy and epilepsy. These diseases pose a major burden for the child and its family, and for society as a whole.
Therefore, in recent years, the Norwegian Institute of Public Health has increased research into risk factors for these disorders, including the presence of harmful chemicals in the environment. Recently, we were awarded funding for a new large project from the Research Council of Norway - NeuroTox - which will provide new knowledge in the field. This will be a major interdisciplinary and international collaboration project with recognised research groups from the United States, China and the UK, as well as many research groups from the Norwegian Institute of Public Health.
In ongoing projects and in NeuroTox, we will measure levels of environmental contaminants in the mother's blood or urine to indicate what the foetus is exposed to. We have chosen substances that are known or suspected to interfere with brain development:
- Perfluorinated substances (eg PFOS, FPOA)
- Heavy metals (mercury, lead, manganese, arsenic, etc.)
- Phthalates (plasticisers)
- Organophosphate pesticides
We will also investigate whether mixtures of these substances are more harmful than single substances alone (a so-called "cocktail effect").
In addition, we will measure metabolic hormones (eg thyroxine) in the mother during pregnancy and in newborns because environmental contaminants can affect brain development by interfering with levels of these important hormones. We will study epigenetic changes in DNA in newborns. Epigenetics are the function of the genes (ie which genes are turned on and off) and are closely linked to brain development. Environmental contaminants that can cause epigenetic changes can thus be another cause of abnormal development.
In these studies we use data from the Norwegian Mother and Child Study (MoBa); including questionnaire data, biological samples of mother and child, clinical examinations (testing of cognitive skills and assessment of psychiatric symptoms) as well as information about the diagnoses of ADHD, autism, cerebral palsy and epilepsy in the child through the link between MoBa and the Norwegian Patient Registry. This is a unique compilation of data and makes it possible to test the hypotheses as to how contaminants and their mixtures can change normal brain development during foetal life, even at the relatively low levels of environmental contaminants we have in Norway.