Settled dust can function as a pollutant sink for compounds, such as polycyclic aromatic hydrocarbons (PAHs) and metal(loid)s (MMs), which may lead to health issues. Thus, dust represents a hazard specifically for young children, because of their vulnerability and hand-to-mouth behavior favoring dust ingestion.The aim of the present study was to explore the influence of the season and the microenvironment on the concentrations of 15 PAHs and 17 MMs in indoor and outdoor settled dust in three preschools (suburban, urban, and industrial). Second, the potential sources and health risks among children associated with dust PAHs and MMs were assessed. Third, domestic factors (risk perception, knowledge and parental style) were described to explore protective parental behaviors toward dust hazards.The suburban preschool had the lowest concentrations of dust PAHs and MMs, while the industrial and urban preschools had higher but similar concentrations. Seasonal tendencies were not clearly observed. Indoor dusts reflected the outdoor environment, even if specific indoor sources were noted. Source analysis indicated mainly vehicular emissions, material release, and pyrogenic or industrial sources. The non-cancer health risks were nonexistent, but potential cancer health risks (between 1.10(-6) and 1.10(-4)) occurred at all sampling locations. Notably, the highest cancer risk was observed in a playground area (>1.10(-4)) and material release should be further addressed. Whereas we assessed higher risk indoors, parents perceived a higher risk in the open-air environment and at the preschool than at home. They also perceived a lower risk for their own children, revealing an optimism bias, which reduces parental anxiety.