Table 9.

Summary of sulphur dioxide exposure levels by plant and job group, actual concentrations after 6–8 h sampling time

Job group	Sulphur dioxide (p.p.m.)
	Plant A								Plant B								Plant C
						Maximum peak valuea								Maximum peak valuea								Maximum peak valuea
	Nb	Kc	GM	GSDd	GM	GMe	GM	P95f	Nb	Kc	GM	GSDd	GMe	GM	GMe	P95f	Nb	Kc	GM	GSDd	GMe	GM	GMe	P95f
Furnace
Mix	12	3	0.001	11	0.001	0.45	0.45	2.3									10	4	0.008	3.4	0.007	0.63	0.62	3.0
Charger																	10	4	0.37	2.1	0.37	5.0	5.0	11
Charger/mix																	10	5	0.37	1.9	0.37	6.9	7.1	18
Payloader	9	2	0.002	15	0.002	0.72	0.72	3.6	5	1	0.006	25	0.006	0.42	0.42	0.90	18	7	0.065	2.8	0.065	0.74	0.73	2.2
Crane	23	8	0.016	3.6	0.016	2.3	2.3	8.1	22	6	0.28	2.3	0.28	9.6	9.6	19	12	6	0.013	3.7	0.013	2.0	2.0	6.7
Control room	20	6	0.036	3.6	0.036	3.2	3.2	58	20	5	0.27	2.9	0.27	13	13	36	17	8	0.061	2.6	0.061	4.0	4.0	17
Cleaning	1	1	NA	NA	NA	NA	NA	NA
Sorting	3	2	NA	NA	NA	NA	NA	NA	19	4	0.19	4.0	0.19	2.7	2.7	24	20	9	0.12	4.1	0.12	2.0	2.1	6.0

The Norwegian OEL for sulphur dioxide is 2 p.p.m. (The Norwegian Labour Inspection Authority, 2007).

NA, not applicable, all measurements below limit of detection, a measurement is below the limit of detection when all its 10-s reading periods are <0.2 p.p.m.

^aMaximum observed peak value for a 10-s averaging period within shift measurements.

^bNumber of measurements.

^cNumber of persons.

^dGeometric standard deviation.

^eGM adjusted with linear mixed effect models.

^f95th percentile adjusted with linear mixed effect models.