Table 5.

Air pollutant concentrations in the conventional cage (CC), aviary (AV) and enriched colony (EC) houses under different ranges of ambient temperature conditions.

Gas or PM	Daily mean ambient	Daily mean concentration (mean ± SD)
	temperature range °C	CC	AV	EC
NH3, ppm	<−10	6.3a,B ± 2.7 (18)	14.4a,A ± 5.3 (16)	4.8a,C ± 1.3 (18)
	−10 to 0	6.2a,B ± 2.6 (130)	12.7a,A ± 6.3 (128)	4.5a,B ± 1.8 (130)
	0 to 10	4.1b,B ± 1.9 (132)	7.4b,A ± 5.4 (132)	2.8b,C ± 1.3 (132)
	10 to 20	2.7cd,A ± 1.4 (151)	3.5c,A ± 1.9 (151)	1.8c,B ± 0.9 (151)
	20 to 25	2.4d,A ± 1.2 (89)	2.8d,A ± 1.6 (89)	1.9c,B ± 1.1 (89)
	>25	3.0c,A ± 1.4 (30)	2.5d,A ± 1.3 (30)	2.4b,A ± 1.4 (30)
CO2, ppm	<−10	4052a,B ± 161 (18)	4787a,A ± 362 (16)	4309a,AB ± 195 (18)
	−10 to 0	3359b,C ± 291 (130)	4027b,A ± 400 (128)	3537b,B ± 360 (130)
	0 to 10	2448c,C ± 309 (132)	3016c,A ± 413 (132)	2672c,B ± 360 (132)
	10 to 20	1402d,C ± 285 (151)	1680d,A ± 389 (151)	1480d,B ± 335 (151)
	20 to 25	891e,B ± 110 (89)	972e,A ± 163 (89)	931e,AB ± 127 (89)
	>25	722f,A ± 95 (30)	721f,A ± 77 (30)	746f,A ± 107 (30)
CH4, ppm	<−10	8.4d,A ± 5.8 (10)	8.2d,A ± 4.7 (10)	9.3d,A ± 6.4 (10)
	−10 to 0	8.7d,A ± 5.5 (105)	9.7d,A ± 5.1 (104)	9.8d,A ± 6.0 (105)
	0 to 10	10.1d,A ± 4.7 (87)	11.4d,A ± 4.6 (87)	11.5d,A ± 5.1 (87)
	10 to 20	12.5c,A ± 6.0 (86)	13.0c,A ± 6.1 (86)	13.1c,A ± 6.3 (86)
	20 to 25	14.4b,A ± 4.2 (39)	14.3b,A ± 4.2 (39)	15.0b,A ± 4.5 (39)
	>25	16.8a,A ± 3.0 (10)	16.5a,A ± 3.0 (10)	17.1a,A ± 3.0 (10)
PM10, mg/m3	<−10	0.68ab,B ± 0.11 (12)	7.38a,A ± 1.69 (7)	0.59a,B ± 0.14 (10)
	−10 to 0	0.68a,B ± 0.11 (83)	6.80a,A ± 1.66 (52)	0.56a,B ± 0.15 (85)
	0 to 10	0.69a,B ± 0.15 (68)	6.11a,A ± 1.72 (50)	0.58a,B ± 0.13 (69)
	10 to 20	0.56b,B ± 0.13 (99)	3.33b,A ± 1.85 (75)	0.41b,C ± 0.12 (110)
	20 to 25	0.42c,B ± 0.12 (53)	1.14c,A ± 0.89 (55)	0.28c,C ± 0.10 (70)
	>25	0.39c,A ± 0.10 (17)	0.38d,A ± 0.33 (22)	0.21d,B ± 0.12 (27)
PM2.5, mg/m3	<−10	-	0.762a,A ± 0.039 (7)	0.073a,B ± 0.017 (13)
	−10 to 0	0.047a,B ± 0.011 (10)	0.710a,A ± 0.116 (40)	0.072a,B ± 0.013 (67)
	0 to 10	0.040a,b,B ± 0.014 (39)	0.510b,A ± 0.122 (46)	0.062a,B ± 0.021 (51)
	10 to 20	0.032c,B ± 0.012 (70)	0.263c,A ± 0.132 (73)	0.048b,B ± 0.021 (109)
	20 to 25	0.030c,A ± 0.010 (16)	0.066d,A ± 0.029 (17)	0.044b,A ± 0.015 (41)
	>25	0.036c,A ± 0.006b (7)	0.053e,A ± 0.013 (7)	0.050b,A ± 0.019 (15)

Note: Values outside parentheses are mean±SD for concentrations. Values inside parentheses are the number of data. For each gas or PM, within a housing system (i.e., within each column), means with different lower case superscripts are significantly different (P < 0.05). Among the housing systems (i.e., within each row), means with different upper case superscripts are significantly different (P < 0.05).