Table 2

Results of biological monitoring for urinary cobalt, nickel, and tungsten in different workshops

Workshop	Workers n	Metal	Mean (95% CI) μg/g creatinine	Median μg/g creatinine	Range μg/g creatinine
Forming		23	Co	13.5 (3.7 to 23.3)	4.2	0.75–106.4
			W	10.7 (6.7 to 14.6)	9.5	0.33–33.1
			Ni	0.40 (0.19 to 0.62)	0.3	< DL–2.2

Pressing		30	Co	5.5 (2.9 to 8.1)	2.8	0.36–35.9
			W	8.6 (4.1 to 13.1)	6.5	1.5–71.0
			Ni	0.42 (0.28 to 0.56)	0.4	< DL–1.6

Heavy alloy production		3	Co	1.6 (0.15 to 3.0)	1.4	1.1–2.2
			W	24.9 (−34.9 to 84.8)	21.6	2.6–50.5
			Ni	2.9 (−4.8 to 10.6)	2.2	0.21–6.3

Powder processing		14	Co	28.5 (−5.6 to 62.7)	11.2	0.75–227.8
			W	12.2 (8.0 to 16.5)	11.6	2.6–25.1
			Ni	0.53 (0.04 to 1.0)	0.1	< DL–3.1

Production of tungsten carbide		4	Co	2.1 (−1.9 to 6.0)	1.1	0.31–5.7
			W	42.1 (4.3 to 79.9)	48.9	10.0–60.6
			Ni	0.91 (0.13 to 1.7)	0.8	0.51–1.5

Sintering		6	Co	4.1 (0.12 to 6.0)	2.6	0.31–9.6
			W	12.5 (−5.7 to 30.7)	5.5	2.1–46.8
			Ni	0.47 (0.11 to 0.84)	0.4	< DL–1.0

Grinding		5	Co	2.2 (−0.57 to 5.0)	1.4	0.19–6.0
			W	94.4 (11.2 to 177.5)	70.9	10.6–168.6
			Ni	0.25 (0.02 to 0.48)	0.2	< DL–0.5

Maintenance		2	Co	3.0 (−18.9 to 24.9)	3.0	1.3–4.7
			W	3.4 (−21.1 to 27.8)	3.4	1.5–5.3
			Ni	0.63 (−3.5 to 4.7)	0.6	0.31–1.0