Table 4.

Determinants of Mus m 1 and Rat n 1 exposure in lab/operation rooms, animal rooms, and cage washrooms of Norwegian laboratory animal facilities.

Ln Mus m 1	B	SE	P	95% CI	Effect	Ln Rat n 1	B	SE	P	95% CI	Effect
Lab/operation room (r 2 adj = 0.21)						Lab/operation room (r 2 adj = 0.74)
Intercept	−0.07	0.52	0.90	−1.19 to 1.05		Intercept	−2.12	0.09	<0.001	−2.33 to −1.92
Bench type: LAF	−1.77	0.79	0.04	−3.46 to −0.08	0.2	Bench type: ventilated	1.03	0.18	<0.001	0.62 to 1.43	2.8
Animal room (r 2 adj = 0.41)						Animal room (r 2 adj = 0.50)
Intercept	3.65	0.46	<0.001	2.72 to 4.57		Intercept	−1.07	0.52	0.04	−2.11 to −0.03
Bench type: ordinary	−1.82	0.60	0.004	−3.01 to −0.62	0.2	Task: changing cages	1.43	0.51	0.006	0.42 to 2.45	4.2
Cage: IVC+	−2.11	0.62	0.001	−3.34 to −0.88	0.1	Cage: IVC−	−2.22	0.38	<0.001	−2.98 to −1.47	0.1
Cage: IVC−	−3.78	0.54	<0.001	−4.85 to −2.70	0.02	Cage-racking system: open shelves with sliding doors	2.65	0.82	0.002	1.16 to 4.28	14
Cage washroom (r 2 adj = 0.71)						Cage washroom (r 2 adj = 0.75)
Intercept	2.82	0.54	<0.001	1.70 to 3.94		Intercept	−1.73	0.36	<0.001	−2.47 to −0.99
Cage: IVC+	5.08	0.85	<0.001	3.31 to 6.84	160	Cage: IVC+	3.24	0.62	<0.001	1.95 to 4.53	26
Cage-racking system: IVC	−2.73	0.79	0.002	−4.37 to −1.09	0.07
Cage-racking system: open  shelves with sliding doors	4.26	1.03	0.001	2.11 to 6.40	71	Cage-racking system: open shelves with sliding doors	6.12	0.76	<0.001	4.54 to 7.69	455

The effect of the determinants, e^B, where B is the coefficient of the determinant, is a factor that multiplied with e^B for the intercept of the exclusive room will give the exposure effect of the determinant. That is, work in animal room with changing IVC− rat cages will give the following Rat n 1 exposure: e^{B(intercept for animal room)} × e^{BTask: changing cages} × e^{BCage: IVC negative} = 0.3 × 4.2 × 0.1 = 0.13 ng m⁻³