Health Assessment Document for Diesel Emissions - NSCEP | US ...

1 8.4.7. Steineck et al. (1990): Increased Risk ofUrothelial Cancer in Stockholm From 1985
2 to 1987, After Exposure to Benzene and Exhausts
3 This study was conducted to investigate the association between benzene, diesel, and
4 petrol exhausts as well as some other industry-related chemicals and the risk ofurothelial cancer.
5 Designed as a population-based case-control study, it was conducted among all men born
6 between 1911 and 1945 and living in the County of Stockholm for all or part ofthe observation
7 period (September 15, 1985, to November 30, 1987). All incident cases ofurothelial cancer and
8 squamous-cell carcinoma of the lower urinary tract were contacted for jnclusion in the study.
9 Controls were selected by stratified random sampling during the observation period from a
1 0 computerized register for the population of Stockholm. A postal questionnaire was sent to study
11 subjects at their homes to collect information on occupational history. The questions on
12 occupation included exposure to certain specified occupations/industries/chemicals and lists of
13 all jobs held and duration in each job. An industrial hygienist, unaware of case-control status,
14 classified subjects as being exposed or unexposed to 38 agents and groups of substances,.
15 including 17 exposure categories with aromatic amines. Using all the exposure information, the
16 exposure period was defined and the annual dose was rated as low, moderate, or high based on
17 the accumulated dose (exposure duration multiplied by intensity of exposure) during the course
18 of 1 average year for the defined exposure period. Swedish and international data were used to
19 classify subjects as exposed, based on air concentrations in the. work environment that were
20 higher than-for the general public, or skin contact with liquids of low volatility. To allow for
21 latency, the authors ignored exposures after 1981. Data were gathered from 256 cases and 287
22 controls. Controls were selected by stratified random sampling four times from the computerized
23 register during the observation period ofthe population ofthe County of Stockholm. These
24 subjects comprised 80% of eligible cases and 79% of eligible controls. Nine of the cases and
25 16% of the controls refused to participate in. the study. The distribution ofurothelial cancers was
26 as follows: 5 tumors in the renal pelvis, 243 in the urinary bladder, 5 in the ureter, none in the
27 urethra, and 3 at multiple sites. Two cases who were exposed to a high annual dose of aromatic
28 amines were omitted from all further analysis to eliminate their confounding effects. Crude
29 relative risks were calculated for men classified as exposed or not exposed to several substances.
30 TwentY:·five cases and 19 controls reported having been exposed to diesel exhaust, yielding an
31 odds ratio of 1.7 (95% CI = 0.9, 3.3). The corresponding relative oddsfor petrol exhausts, based
32 on 24 cases and 24 controls, were 1.0 (95% CI = 0.5, 1.9). Odds ratios were then calculated for
33 low, moderate, and high levels of the annual dose adjusted for smoking and year of birth. :For
. 34 diesel exhausts, the odds ratio was 1.3 (95% CI = 0.6, 3.1) for low levels, 2.2 (95% CI = 0.7, 6.6)
35 for moderate levels, and 2.9 (95% CI = 0.3, 30.0) for high levels, indicating a dose response.
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