Evaluation of PM₁, PM_2.5, and PM₁₀ exposure and the resultant health risk of preschool children and their caregivers

Preschool children have a higher respiratory rate per unit body weight than adults, and their respiratory systems are not mature. Hence, children may have more health risks associated with particulate matter (PM) exposure. In this study, we assessed the exposure of preschool children and their caregivers to PM and the resulting health risks. The PM concentrations at heights of 60–80 cm (preschool children) and 150 cm (adults) were measured at ten indoor and eight outdoor sites in the Taipei metropolitan area from March 2015 to February 2017. Four PM_2.5 and seven PM₁₀ indoor measurements exceeded the indoor air quality standard of Taiwan, whereas only two PM_2.5 outdoor measurements exceeded the ambient air quality standard. The outdoor PM concentrations were related to traffic emissions, whereas the indoor PM concentrations were associated with ventilation rate and occupant density. The chronic daily PM₁, PM_2.5, and PM₁₀ intakes of preschool children were notably higher than those of adults. In addition, the hazard quotient resulting from PM_2.5 exposure indicated a significant health risk for preschool children (93.74% greater than 1). Consequently, reducing the exposure of preschool children to PM_2.5 is an emerging issue in the Taipei metropolitan area.