Table 4.

Classification of semiconductor workers based on the distribution of ELF-MF exposure level.

Classification	Operation	Type of Job	No of Samples	AM, uT	SD, uT	GM, uT	GSD	Range, uT	Relative Exposure Group 1
Fabrication	CMP	M/E	44,242	0.14	0.29	0.09	2.47	0.01–16.83	Low
	Photolithography	M/E	53,883	0.53	0.46	0.37	2.54	0.02–21.97	Moderate
	Etch	M/E	98,151	0.53	0.64	0.37	2.40	0.01–23.52	Moderate
	Diffusion	Operator	16,869	1.69	0.81	1.48	1.71	0.11–4.93	High
		M/E	41,803	1.40	2.30	0.46	5.10	0.01–35.36	High
	Ion implantation	Operator	17,099	1.74	0.68	1.50	1.97	0.04–12.31	High
		M/E	43,551	0.37	0.74	0.17	3.20	0.01–15.67	Low
	Thin film	Operator	8395	0.24	0.40	0.18	1.86	0.04–5.93	Low
		M/E	58,203	0.45	0.81	0.18	3.90	0.01–17.31	Moderate
	Wafer test	Operator	64,624	0.19	0.25	0.12	2.66	0.01–9.63	Low
		M/E	28,195	0.27	0.36	0.19	2.34	0.01–7.99	Low
Chip packaging	Die attach	Operator	51,536	0.53	0.39	0.41	2.10	0.03–15.39	Moderate
		M/E	17,616	0.25	0.26	0.16	2.41	0.01–4.17	Low
	Module	Operator	18,601	1.46	1.48	0.76	3.67	0.02–6.27	High
		M/E	28,800	0.91	0.82	0.50	3.38	0.01–4.55	High
	Module test	Operator	28,799	0.56	0.52	0.43	1.99	0.04–7.71	Moderate
		M/E	76,218	0.32	0.37	0.23	2.17	0.02–3.81	Moderate
	TDBI	Operator	24,578	0.43	0.34	0.33	2.00	0.04–7.43	Moderate
		M/E	81,234	0.37	0.40	0.26	2.40	0.03–26.72	Moderate
	Test	Operator	32,480	1.46	0.90	1.24	1.80	0.08–21.92	High
Electric maintenance	Maintenance	M/E	91,481	0.89	3.11	0.27	3.55	0.01–109.0	High
	Management	Manager	16,526	0.28	0.42	0.13	4.06	0.01–9.66	Low

Abbreviations: CMP: chemical mechanical polishing, TDBI: test during burn-in, M/E: maintenance engineer, AM: arithmetic mean, SD: standard deviation, GM: geometric mean, GSD: geometric standard deviation. ¹ Low: AM < 0.3 µT, Moderate: 0.3 ≤ AM < 0.65 µT, High: AM ≥ 0.65 µT.