Table 3.

Indoor air pollutions measurements in the case and control groups

	Control(N = 77)	Case(N = 53)	P value
TVOCsc
Median(IQR) (mg/m3)	0.005(0.01)	0.40(0.98)
Range (mg/m3)	0.005–1.85	0.005–7.02
Number at or above the MDL[n(%)]	20[28.6%]	41[77.4%]
Number over reference limit [n(%)]	4[5.2%]	20[37.7%]	<0.001a
Benzenec
Median (IQR) (mg/m3)	0.005(0)	0.005(0.06)
Range (mg/m3)	0.005-1.0	0.005-1.0
Number at or above the MDL[n(%)]	9[11.7%]	22[41.5%]
Number over reference limit[n(%)]	9[11.7%]	22[41.5%]	<0.001a
Toluenec
Median (IQR) (mg/m3)	0.005(0)	0.005(0.20)
Range (mg/m3)	0.005-0.6	0.005-1.0
Number at or above the MDL[n(%)]	11[14.3%]	24[45.3%]
Number over reference limit [n(%)]	3[3.9%]	2[3.8%]	1a
Xylenec
Median (IQR) (mg/m3)	0.005(0)	0.005(0.16)
Range (mg/m3)	0.005-0.6	0.005-1.4
Number at or above the MDL[n(%)]	10[13.0%]	22[41.5%]
Number over reference limit [n(%)]	5[6.5%]	2[3.8%]	0.7a
Formaldehydec
Median (IQR) (mg/m3)	0.02(0.033)	0.01(0.015)
Range (mg/m3)	0.005–0.79	0.005–0.609
Number at or above the MDL[n(%)]	72[93.5%]	52[98.1%]
Number over reference limit [n(%)]	11[14.3%]	7[13.2%]	0.86 a
Temperature
Median (IQR) (℃)	28.7(5)	25(6)	<0.001b
Humidness
Median (IQR) (%)	47(15)	38(10.5)	0.002b

a: P value was calculated by Chi-square analysis or Fisher exact tests. b: P value was calculated by Mann–Whitney U-test. c: TVOCs, Benzene, toluene and xylene and formaldehyde concentrations below the method of detection limit (MDL) of 0.01mg/m³ were replaced with 0.005 mg/m³ in all analyses