Silica and asbestos exposure at work and the risk of bladder cancer in Canadian men: a population-based case-control study

Table 2 Select characteristics of bladder cancer cases and controls from the NECSS, 1994–1997

Characteristic	Cases		Controls
Characteristic	N	%	N	%	OR ^a	95% CI
Age at interview
40- < 50	52	7.9	137	10.1
50- < 60	126	19.2	239	17.6
60- < 70	283	43.0	581	42.7
≥ 70	197	29.9	403	29.6
Province of residence
Newfoundland	42	6.4	105	7.7
Prince Edward Island	15	2.3	63	4.6
Nova Scotia	60	9.1	307	22.6
Manitoba	88	13.4	126	9.3
Saskatchewan	62	9.4	120	8.8
Alberta	196	29.8	265	19.5
British Columbia	195	29.6	374	27.5
Proxy respondent
No	405	61.6	902	66.3	1.00
Yes	253	38.5	458	33.7	1.30	1.06–1.59
Cigarette pack-years
Never smoker	76	11.6	302	22.2	1.00
> 0- < 10	67	10.2	223	16.4	1.15	0.79–1.68
10- < 20	120	18.2	233	17.1	1.93	1.37–2.72
20- < 30	126	19.2	214	15.7	2.39	1.70–3.38
30- < 40	121	18.4	147	10.8	3.53	2.46–5.07
≥ 40	137	20.8	217	16.0	2.70	1.91–3.81
Unknown	11	1.7	24	1.8	1.72	0.79–3.73
p_-trend					< 0.001
Ever exposure to aromatic amines at work
No	652	99.1	1348	99.1	1.00
Yes	6	0.9	12	0.9	1.36	0.49–3.79
Highest attained concentration of diesel emissions exposure
Unexposed	402	61.1	869	63.9	1.00
Low	162	24.6	377	27.7	0.88	0.70–1.10
Medium	66	10.0	89	6.5	1.46	1.03–2.08
High	28	4.3	25	1.8	2.60	1.47–4.61
p_-trend					0.007
Self-reported exposure to wood dust at work
No	506	76.9	1027	75.5	1.00
Yes	152	23.1	333	24.5	0.97	0.77–1.21
Self-reported exposure to mineral/lube oil at work
No	496	75.4	1133	83.3	1.00
Yes	162	24.6	227	16.7	1.60	1.27–2.03
Self-reported exposure to welding dust at work
No	490	74.5	1101	81.0	1.00
Yes	168	25.5	259	19.0	1.44	1.15–1.81
Self-reported exposure to benzene at work
No	616	93.6	1313	96.5	1.00
Yes	42	6.4	47	3.5	1.97	1.27–3.07
Self-reported exposure to benzidine at work
No	639	97.1	1344	98.8	1.00
Yes	19	2.9	16	1.2	2.62	1.31–5.23
Total	658	100.0	1360	100.0

^aPresented odds ratios (OR) are adjusted for age at interview, province of residence, and proxy respondent.

ISSN: 1471-2407