Table 3. Relative risks (RRs) of mortality for stripping/removal workers, using Poisson regression analyses.

	All causes			All MN			MN Trachea, bronchus & lung
	Cases	RRa (95% CI)	LR test (d.f.)	Cases	RRa (95% CI)	LR test (d.f.)	Cases	RRa (95% CI)	LR test (d.f.)
Main stripping method			4.03 (2)			2.35 (2)			2.71 (2)
Wetc	397	1.0		141	1.0		48	1.0
Dry	409	1.1 (0.9–1.2)		169	1.2 (0.9–1.5)		39	0.8 (0.5–1.2)
Both	48	0.8 (0.6–1.1)		21	1.0 (0.6–1.6)		13	1.3 (0.7–2.7)
Main respirator type			2.82 (6)		10.20 (6)				6.28 (6)
Positive pressure maskc	664	1.0		245	1.0		70	1.0
Airstream helmet	4	—		1	—		1	—
Full face unpowered mask	127	1.0 (0.8–1.2)		55	1.1 (0.8–1.5)		16	1.1 (0.6–1.8)
Half face mask	18	0.8 (0.5–1.3)		4	—		1	—
Minimal	14	0.7 (0.4–1.3)		5	—		2	—
None	2	—		2	—		1	—
Mixed	51	1.1 (0.8–1.5)		25	1.4 (0.9–2.2)		11	1.7 (0.9–3.5)
Weekly hours spent stripping			14.97 (4)**			1.00 (4)			0.87 (4)
<10c	483	1.0		222	1.0		66	1.0
10−	74	1.0 (0.8–1.2)		32	1.0 (0.7–1.5)		8	0.9 (0.4–1.8)
20−	125	1.1 (0.9–1.4)		48	1.1 (0.8–1.5)		12	1.0 (0.5–1.8)
30−	124	1.3* (1.0–1.5)		33	0.9 (0.6–1.3)		9	0.9 (0.4–1.7)
40+	163	1.4** (1.2–1.7)		44	1.0 (0.7–1.4)		15	1.2 (0.7–2.1)
Smoking status		112.42 (2)**				41.07 (2)**			67.66 (2)**
Never smokersc	118	1.0		38			1	1.0
Current smokers	622	2.5** (2.0–3.0)		216	1.0		86	43.0** (6.0–305.8)
Former smokers	225	1.5** (1.2–1.9)		125	2.8** (1.9–3.9)		26	16.0** (2.2–118.4)
Age at first exposure (years)		14.80 (4)**				2.2** (1.5–3.1)			3.22 (4)
<20c	184	1.0		91	1.0		21	1.0
20−	278	1.1 (0.9–1.3)		81	0.9 (0.7–1.2)		18	1.0 (0.5–1.8)
30−	193	0.9 (0.8–1.1)		70	0.8 (0.6–1.1)		23	1.2 (0.7–2.1)
40−	211	1.1 (0.9–1.3)		84	0.7* (0.5–1.0)		33	1.2 (0.7–2.0)
50+	119	0.7** (0.6–0.9)		58	0.6** (0.4–0.8)		20	0.7 (0.4–1.3)
Length of time in the survey			0.01 (1)			14.81 (1)**			5.13 (1)*
Short-termc	419	1.0		116	1.0		33	1.0
Long-term	599	1.0 (0.9–1.1)		268	1.5** (1.2–1.9)		82	1.6* (1.1–2.4)
Length of exposure (years)			16.29 (4)**			18.61 (4)**			6.88 (4)
<10c	553	1.0		166	1.0		49	1.0
10−	161	1.0 (0.8–1.2)		60	1.1 (0.8–1.5)		26	1.6 (1.0–2.5)
20−	88	0.8 (0.7–1.0)		45	1.1 (0.8–1.5)		11	0.8 (0.4–1.6)
30−	94	1.0 (0.8–1.2)		61	1.4* (1.1–1.9)		14	1.0 (0.5–1.8)
40+	89	1.5** (1.2–2.0)		52	2.1** (1.5–2.9)		15	1.7 (0.9–3.2)
Time of first exposure			0.00 (1)			4.02 (1)*			1.43 (1)
Pre-ALRc	430	1.0		217		1.0	66	1.0
Post-ALR	555	1.0 (0.9–1.1)		167		0.8* (0.7–1.0)	49	0.8 (0.5–1.2)
	Mesotheliomab			Circulatory disease			Ischaemic heart disease
	Cases	RRa (95% CI)	LR test (d.f.)	Cases	RRa (95% CI)	LR test (d.f.)	Cases	RRa (95% CI)	LR test (d.f.)
Main stripping method			3.25 (2)			6.81 (2)*			8.61 (2)*
Wetc	12	1.0		109	1.0		77	1.0
Dry	10	0.9 (0.4–2.1)		107	1.0 (0.7–1.3)		66	0.9 (0.6–1.2)
Both	0	—		7	0.4* (0.2–0.9)		3	—
Main respirator type			10.14 (6)			1.54 (6)			2.24 (6)
Positive pressure maskc	20	1.0		172	1.0		110	1.0
Airstream helmet	0	—		1	—		1	—
Full face unpowered mask	1	—		34	1.0 (0.7–1.4)		24	1.1 (0.7–1.7)
Half face mask	0	—		7	1.1 (0.5–2.5)		5	—
Minimal	0	—		4	—		2	—
None	1	—		0	—		0	—
Mixed	1	—		12	1.0 (0.5–1.7)		9	1.2 (0.6–2.3)
Weekly hours spent stripping			2.29 (1)			12.34 (4)*			11.42 (4)*
<10c	17	1.0		133	1.0		86	1.0
10−	6	0.5 (0.2–1.3)		16	0.8 (0.5–1.4)		12	1.0 (0.5–1.8)
20−	—			28	1.1 (0.7–1.6)		16	0.9 (0.6–1.6)
30−	—			32	1.4 (0.9–2.1)		24	1.6* (1.0–2.6)
40+	—			47	1.7** (1.2–2.4)		32	1.9** (1.2–2.8)
Smoking status			2.27 (2)			33.41 (2)**			35.14 (2)**
Never smokersc	5	1.0		38	1.0		19	1.0
Current smokers	7	0.7 (0.2–2.3)		161	2.1** (1.4–2.9)		114	2.9** (1.8–4.7)
Former smokers	11	1.5 (0.5–4.4)		53	0.9 (0.6–1.4)		34	1.2 (0.7–2.1)
Age at first exposure (years)			22.12 (1)**			12.38 (4)*			12.71 (4)*
<20c	14	1.0		44	1.0		33	1.0
20−	9	0.1** (0.1–0.3)		41	0.8 (0.5–1.2)		19	0.5* (0.3–0.9)
30−	—			51	1.0 (0.7–1.6)		34	0.9 (0.6–1.5)
40−	—			78	1.5* (1.0–2.2)		54	1.3 (0.9–2.1)
50+	—			44	0.9 (0.6–1.4)		31	0.9 (0.5–1.5)
Length of time in the survey			8.23 (1)**			0.00 (1)			0.60 (1)
Short-termc	3	1.0		102	1.0		72	1.0
Long-term	20	4.5* (1.3–16.0)		156	1.0 (0.8–1.3)		99	0.9 (0.6–1.2)
Length of exposure (years)			18.59 (1)**			7.19 (4)			10.39 (4)*
<10c	—			141	1.0		92	1.0
10−	—			48	1.0 (0.7–1.4)		36	1.2 (0.8–1.7)
20−	9d	1.0		27	0.8 (0.5–1.2)		14	0.6 (0.3–1.0)
30−	14	7.3** (2.5–21.6)		20	0.6* (0.4–0.9)		13	0.6* (0.3–1.0)
40+	—			22	0.9 (0.6–1.5)		16	1.1 (0.6–1.9)
Time of first exposure			13.15 (1)**			0.46 (1)			0.84 (1)
Pre-ALRc	19	1.0		123	1.0		81	1.0
Post-ALR	4	—		135	1.1 (0.8–1.4)		90	1.2 (0.8–1.6)
	Cerebrovascular disease			Respiratory disease
	Cases	RRa (95% CI)	LR test (d.f.)	Cases	RRa (95% CI)	LR test (d.f.)
Main stripping method			0.62 (2)			2.46 (2)
Wetc	18	1.0		23	1.0
Dry	14	0.8 (0.4–1.5)		13	0.6 (0.3–1.2)
Both	2	—		4	—
Main respirator type			7.12 (6)			4.02 (6)
Positive pressure maskc	31	1.0		33	1.0
Airstream helmet	0	—		0	—
Full face unpowered mask	4	—		4	—
Half face mask	0	—		0	—
Minimal	1	—		1	—
None	0	—		0	—
Mixed	0	—		3	—
Weekly hours spent stripping			0.68 (2)			3.46 (3)
<10c	21	1.0		21	1.0
10−	10	1.4 (0.6–2.9)		8	1.1 (0.5–2.5)
30−	10	1.2 (0.6–2.7)		7	2.0 (0.8–4.6)
40+	—			8	1.9 (0.9–4.1)
Smoking status			5.96 (2)			14.18 (2)**
Never smokersc	12	1.0		2	1.0
Current smokers	22	0.9 (0.4–1.8)		30	7.4** (1.8–30.6)
Former smokers	6	0.3* (0.1–0.9)		11	3.8 (0.8–17.2)
Age at first exposure (years)			3.04 (4)			4.35 (3)
<20c	6	1.0		6	1.0
20−	8	1.1 (0.4–3.2)		12	1.7 (0.7–4.8)
30−	8	1.5 (0.5–4.7)		12	2.1 (0.8–5.3)
40−	12	2.2 (0.8–6.6)		14	1.0 (0.4–2.6)
50+	7	1.3 (0.4–4.4)		—
Length of time in the survey			0.45 (1)			0.46 (1)
Short-termc	15	1.0		20	1.0
Long-term	26	1.2 (0.7–2.3)		24	0.8 (0.5–1.5)
Length of exposure (years)			0.94 (2)			7.14 (3)
<10c	24	1.0		25	1.0
10−	6	0.8 (0.3–1.9)		6	0.4 (0.2–1.1)
20−	11	0.7 (0.3–1.5)		—
30−	—			6	1.1 (0.4–2.7)
40+	—			7	1.9 (0.8–4.4)
Time of first exposure			1.16 (1)			0.01 (1)
Pre-ALRc	18	1.0		22		1.0
Post-ALR	23	1.4 (0.7–2.8)		22	1.0 (0.5–1.8)

^*significant at P⩽0.05; ^**significant at P⩽0.01; LR test=Likelihood ratio test of goodness-of-fit; d.f.=degrees of freedom; CI=confidence interval.

^aRelative risk adjusted with Poisson regression for age, calendar period and sex.

^bICD-10, post-2001.

^cReference category.

^dCategories: <30, 30+.