A major contribution of the pediatrician is to help families rank the multitude of pollutants according to their known risk for child health. Elimination of household smoking and completely effective venting of indoor heating devices are beneficial to all and mandatory in homes of allergic children. Acute releases of NO2 by gas ranges and ovens may be a significant factor in an increased incidence of respiratory infection, especially in children under two years. Despite intensive investigation, immunosuppressive and other health effects have not been defined for indoor levels of PBBs, PCBs, and related halogenated hydrocarbons. The analytic ability to determine nanomolar concentrations of numerous toxic chemicals opens a Pandora's box of inquiry. New methods, particularly immunologic, are urgently needed to quantitate the dose response to multiple combinations of chemicals and determine their significance for the health of the "tight-box" generation of children.