The present research proposal is in toxicology. It is a cooperation between the Norwegian Institute of Public Health and the School of Pharmacy, University of Oslo. It is focused on the the toxicity of the environmental chemicals/indoor air pollutants bis phenol A (BPA) and phthalates on fetal brain development. Humans are widely exposed to BPA (an additive in the production of polycarbonate plastics and other types of plastic) and phthalates (a class of chemicals used as softeners in polyvinyl chloride pl astics used in a variety of consumer products). EU has recently (april 2008) updated the risk assessment report of BPA, and 50 mg/kg/day was suggested as NOAEL-value (no observed adverse effect level). The scandinavian Pollution Control Authorities was in volved in the discussion of this revised risk assessment report, but did not approve that the NOAEL-value covered neurotoxic effects on the developing nervous system. In risk assessments published by The U.S. National Toxicology Program, Health Canada and Environment Canada (april 2008) some concern is expressed for the effects of BPA on the nervous system and behavior of fetus, babies and children. Phthalates readily crosses the placenta and accumulates in the fetus, and it was recently reported that pht halates may affect the neurodevelopment of the human brain. The aim of this project is to evaluate the neurotoxicity of phthalates and BPA on the developing brain. Both in vivo and in vitro studies will be performed. Cell division rates, apoptosis rates a nd neuronal morphology will be addressed.