Table 2

Exposure measurements by job category, and the values for workers using respirators compared to those without respirators

	n	Inhalable aerosol			Thoracic aerosol			Respirable aerosol
	n	AM	GM	GSD	AM	GM	GSD	AM	GM	GSD
Job category
Production	37	5.2	2.3	4.5	0.65	0.32	3.6	0.37	0.20	3.4
Electrical maintenance	9	5.5	2.7	3.6	0.59	0.37	2.7	0.24	0.19	2.2
Mechanical maintenance	27	7.7	3.5	4.0	1.2	0.59	3.2	0.73	0.33	3.5
Laboratory	3	0.91	0.65	3.2	0.20	0.14	3.3	0.11	0.10	2.0
Other	19	7.8	4.0	4.3	1.1	0.52	4.2	0.46	0.31	2.6
Total	95	6.3	2.8	4.3	0.88	0.42	3.6	0.47	0.24	3.2
Plant 1	39	5.2	2.5	3.8	0.62	0.30	3.5	0.36	0.21	3.0
Without respirator	18	1.4	0.90	2.8	0.16	0.11	2.4	0.13	0.088	2.3
With respirator	21	8.4	6.2^‡	2.2	1.1	0.73^‡	2.1	0.56	0.46^‡	1.9
Plant 2	56	7.1	3.0	4.7	1.1	0.52^*	3.5	0.55	0.27	3.2
Without respirator	43	4.6	2.5	3.7	0.60	0.40	2.8	0.32	0.21	2.5
With respirator	13	15	5.6	8.0	2.5	1.3^†	4.4	1.3	0.58^†	4.8

↵* Significantly different from plant 1, p=0.04.
↵† Significantly different from the category above, p<0.05.
↵‡ p<0.001.
AM, arithmetic mean; GM, geometric mean; GSD, geometric standard deviation.