Table 4.

Whole-body vibration exposures evaluated by weighted, root-mean-square (wRMS) accelerations for axes x, y, and z and vector summations for front-end loader operators at two stone quarries. Weighted acceleration levels for the total sample times were normalised to full-shift equivalent levels to compare with the ISO health guidance caution zone (HGCZ) action and limit boundary level conditions of ISO 2631-1 and the European Union Directive 2002/44/EC presented in the European Union good practices guide (EUGPG)

Quarry	Front-end loader operator	Total sampling time (min)	A(8) wRMS X-axis	A(8) wRMS Y-axis	A(8) wRMS Z-axis	A(8) wRMS vector sum	ISO 2631-1 8-hr shift1 equivalent HGCZ dominant axis	EUGPG 8-hr shift1 equivalent HGCZ dominant axis
1	1	64.7	0.50	0.55	0.53	1.17	Within HGCZ	Within HGCZ
1	2	99.2	1.04	0.93	0.49	2.01	Above HGCZ	Within HGCZ
2	3	80.1	0.88	0.75	0.40	1.67	Within HGCZ	Within HGCZ
2	4	43.8	0.42	0.48	0.35	0.96	Within HGCZ	Below HGCZ
	Mean	72.0	0.71	0.68	0.44	1.45	Within HGCZ	Within HGCZ
	STD	23.5	0.29	0.20	0.08	0.47

¹Full-shift applies to 9-hr daily exposure during a 10-hr shift for wRMS; International Standards Organization (ISO). Units of wRMS are presented as m/s². The activities associated with the front-end loader operator exposures were pushing /moving material, loading haul truck, and roadway travel.