Noting that children may be affected by environmental contaminants in ways quite different from the way adults are affected, this report is the second on trends in measures reflecting environmental factors that may affect the U.S. children's health and well-being. A list of measures and key findings begins the report, followed by five main sections. Several measures throughout the report are analyzed by children's race/ethnicity and family income. Section 1 presents measures showing incidence of exposure to critical concentrations of contaminants in outdoor air, indoor air, water, food, and soil. Section 2 presents measures of lead, mercury, and cotinine (marker of environmental tobacco smoke exposure) measured in the bodies of children and women. Section 3 presents trends in asthma, other severe respiratory illnesses, childhood cancers, and neurodevelopmental disorders such as attention deficit/ hyperactivity disorder and mental retardation. Section 4 concerns the emerging issues of mercury in fish and attention deficit/hyperactivity disorder. Section 5 presents data specific to California and Minnesota. The final section of the report discusses improvements in the measures and data sources and new measures for inclusion in future reports. Major findings presented in the report include declines throughout the 1990s in the percentage of days with unhealthy air quality, median blood lead levels for children under 5, and median blood levels of cotinine; and overall increases in the percentage of children with asthma. The frequency of new childhood cancer cases has been stable since 1990. Recent data indicate that .6 percent of children are diagnosed with mental retardation and 6.7 percent of children are diagnosed with attention deficit/ hyperactivity disorder. State data revealed that 32 percent of California public elementary schools have deterioration of lead-based paint, and 47 percent of Minnesota schools sprayed pesticides in classrooms. A glossary of terms completes the report. Four appendices include data tables and a list of environmental health objectives in the Energy Protection Agency's strategic plan. Each report section contains references. (KB).