Table 1

Demographic characteristics, work history and mortality events of 90 268 US radiological technologists

Demographic variables	N	%	Work history variables	N	%	Mortality events	N	%
Birth year			Year began working			All deaths	9566	100.0
<1930	7600	8.4	<1940	1034	1.2	All cancers	3329	34.8
1930–1934	4570	5.1	1940–1949	4238	4.8	Bladder cancer	47	0.5
1935–1939	7255	8.0	1950–1959	12 115	13.8	Brain cancer	120	1.3
1940–1944	11 483	12.7	1960–1969	26 804	30.5	Breast cancer (female)	518	5.4
1945–1949	17 962	19.9	1970+	43 652	49.7	Colon cancer	234	2.4
1950–1954	23 196	25.7	Age began working (years)			Leukaemia	119	1.2
1955+	18 197	20.2	<20	36 991	42.1	Lung cancer	790	8.3
Age (years)			20–24	39 682	45.2	Stomach cancer	58	0.6
<30	16 435	18.2	25–29	6912	7.9	Oesophageal cancer	52	0.5
30–39	41 268	45.7	30+	4258	4.9	Melanoma	53	0.6
40–49	19 644	21.8	Total years worked			Multiple myeloma	67	0.7
50–59	8012	8.9	<10	44 555	49.4	Non-Hodgkin's lymphoma	139	1.5
60–69	3390	3.8	10–19	34 022	37.7	Ovarian cancer	163	1.7
70+	1514	1.7	20–29	8568	9.5	Uterine cancer	75	0.8
Gender			30+	3078	3.4	All heart disease	2316	24.2
Female	69 500	77.0	Years worked before 1950			Ischaemic heart disease	1558	16.3
Male	20 763	23.0	None	8117	9.0	Cerebrovascular disease	522	5.5
Smoking (pack-years)			1–4	3034	3.4	Digestive disease (non-malignant)	299	3.1
Never	42 357	46.9	5+	2238	2.5	Respiratory disease (non-malignant)	806	8.4
<10	21 551	23.9	Years worked 1950–1959			Infectious disease	86	0.9
10–19	10 941	12.1	None	16 959	18.8
20–29	5758	6.4	1–4	9227	10.2
30–39	3759	4.2	5+	7381	8.2
40+	4106	4.6	Years worked 1960–1969
BMI (kg/m²)			None	36 020	39.9
<18.5	3082	3.4	1–4	21 277	23.6
18.5–24	57 979	64.2	5+	19 305	21.4
25–29	19 719	21.9	Years worked 1970 or later
30+	6956	7.7	None	11 095	12.3
Race			1–4	13 901	15.4
Caucasian	85 583	94.8	5+	65 232	72.3
Non-Caucasian	4669	5.2	Times held patient for X-ray
			None	4194	4.7
			1–9	9228	10.4
			10–24	13 366	15.1
			25–50	15 419	17.4
			50+	46 319	52.3

BMI, body mass index.