Objective To provide basic data of kindergarten indoor air quality in Yinchuan City through the detection and analysis of carbon oxide (CO), carbon dioxide (CO2), formaldehyde (HCHO), volatile organic compounds (VOCs), and total bacteria count in 15 kindergartens in a district of Yinchuan.
Methods From April to June 2014, we selected 45 classrooms of 15 kindergartens in Yinchuan by random sampling method. CO, CO2, VOCs, HCHO in air were measured using portable infrared CO/CO2 analyzer (Model GXH-3010/3011), VOC detector (RAE systems Inc), and HCHO analyzer (Model 4160-19.99), respectively. Koch's settlement method was used to estimate total bacteria count in indoor air. The test results were evaluated according to the Indoor Air Quality Standard (GB/T 18883-2002).
Results In the 45 selected classrooms of 15 kindergartens in Yinchuan City, the maximum of CO2 was 0.122%, 1.22 folds of the CO2 limit by the Indoor Air Quality Standard (GB/T 18883-2002) (<0.1%); the maximum of HCHO was 0.107mg/m3, 1.07 folds of the national HCHO limit (<0.1mg/m3); the CO maximum was 1.000mg/m3 (national standard limit, <1.0 mg/m3); the VOCs maximum was 0.125 mg/m3 (national standard limit, <0.6 mg/m3); the maximum of total bacteria count was 7.4cfu/plate (national standard limit, <45cfu/plate). Statistical difference in indoor VOCs was identified between state-runM(P25-P75), 0.016(0.008-0.044)mg/m3 and private kindergartens0.003(0.000-0.007)mg/m3 (P<0.05).
Conclusion The indoor air quality of selected kindergartens in Yinchuan City is generally good, but the levels of HCHO and CO2 exceed the national standards in a few kindergartens, which requires more attention and comprehensive control measures.
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