Table 4.

Noise exposures at SC level within facility

	N SCs		TWA noise levels						Measurements >85 dBA
			Baseline (1992-1994)		Final (2009- 2011)		Δ Baseline-final		Baseline (1992- 1994)		Final (2009- 2011)		Δ Baseline-final
Location	Baseline (1992- 1994)	Final (2009- 2011)	N*	Mean (dBA)	N*	Mean (dBA)	dBA/yr **	p-value	N*	N (%) >85 dBA	N*	N (%) >85 dBA	> 85 dBA (% per yr) **	p- value
1	19	23	411	81.6	237	80.6	−0.11	0.01	19	2 (10.5)	23	3 (13.0)	−0.14	0.79
2	10	13	146	87.1	247	85.9	−0.18	0.26	10	7 (70.0)	13	9 (69.2)	−1.41	0.22
3	14	14	370	83.8	193	84.4	0.04	0.59	14	4 (28.6)	14	7 (50.0)	1.58	0.03
4	13	23	108	84.4	540	81.2	−0.14	0.35	13	5 (38.5)	23	1 (4.4)	−2.18	0.08
5	20	15	209	85.1	161	79.5	−0.31	0.0003	20	11 (55.0)	15	1 (6.7)	−2.95	0.0001
6	7	8	108	86.9	77	74.5	−0.84	0.002	7	4 (57.1)	8	0 (0)	−3.21	0.01
7	11	19	96	86.7	171	79.6	−0.45	0.00	11	7 (63.6)	19	1 (5.3)	−2.65	0.0005
8	8	8	93	83.7	61	76.9	−0.53	0.01	8	2 (25.0)	8	0 (0)	−2.13	0.02

^*Required at least 3 measurements to be included

^**Weighted by number of SCs in the year