Primary pollutants in schoolchildren's homes in Wuhan, China

• We investigated indoor pollution in the homes of ten schoolchildren in Wuhan.
• Fine particles from outdoor air cause the most severe indoor air pollution.
• DEHP and DBP in house dust are also the primary indoor pollutants.
• TVOCs sometimes lead to indoor air pollution with the levels of over standard.
• Airborne fungi are potential risk for indoor pollution in warm environment.

In 2013, field campaigns were performed in the naturally ventilated homes of ten schoolchildren living in Wuhan's urban area, with purpose to ascertain the primary indoor pollutants that have been associated with respiratory and allergic health in children. According to the 2-week monitoring, mean temperature and relative humidity were 19.5 °C and 60% in autumn and 12.7 °C and 55% in winter, respectively; mean level of carbon dioxide (CO2) was 525 ppm in autumn and 748 ppm in winter. Particulate matter (PM) led to the most severe indoor air pollution with 94% of gravimetric concentrations of PM2.5 far beyond 75 μg/m3. Indoor/outdoor (I/O) ratio of PM2.5 level varied between 0.72 and 1.04; furthermore, statistical analysis proved that indoor PM level was significantly associated with outdoor level (R2 ≥ 0.93, p < 0.001, n = 16). Formaldehyde and acetaldehyde in air samples were always at the levels far below the recommended limits, 100 μg/m3 and 48 μg/m3, respectively; but total volatile organic compounds (TVOCs) were higher than the national standard of 600 μg/m3 in some homes. Furthermore, high levels of di(2-ethylexyl) phthalate (DEHP) and dibutyl phthalate (DBP) were frequently detected in house dust. The results showed that airborne Aspergillus and Penicillium caused some concerns of fungal pollution in autumn. In conclusion, in the homes of the schoolchildren in Wuhan's urban area, airborne PM, and DEHP and DBP in house dust are primary pollutants; sometimes TVOCs also lead to indoor air pollution; in addition, airborne fungal components indicate to be a contributing factor to indoor pollution of concern in warm environment.