Cancer mortality among European asphalt workers: an international epidemiological study. II. Exposure to bitumen fume and other agents.
BACKGROUND
An increased risk of lung cancers among asphalt workers has been suggested in epidemiological studies based on large scale statistical analyses.


METHODS
In a multi-country study of 29,820 male workers employed in road paving, asphalt mixing and roofing, 32,245 ground and building construction workers and 17,757 other workers from Denmark, Finland, France, Germany, Israel, the Netherlands, Norway, and Sweden, with mortality that was documented from 1953-2000. Exposures to bitumen fume, coal tar, 4-6 ring polycyclic aromatic hydrocarbons, organic vapor, diesel exhaust, asbestos, and silica dust were assessed via a job-exposure matrix. Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) based on national mortality rates, as well as relative risks (RRs) based on Poisson regression models were calculated.


RESULTS
The SMR of lung cancer among workers exposed to bitumen fume (1.08, 95% CI 0.99-1.18) was comparable to that of non-exposed workers (SMR 1.05, 95% CI 0.92-1.19). In a sub-cohort of bitumen-exposed workers without exposure to coal tar, the SMR of lung cancer was 1.23 (95% CI 1.02-1.48). The analysis based on the semi-quantitative, matrix-based exposures in the whole cohort did not suggest an increased lung cancer risk following exposure to bitumen fume. However, in an analysis restricted to road pavers, based on quantitative estimate of bitumen fume exposure, a dose-response was suggested for average level of exposure, applying a 15-year lag, which was marginally reduced after adjustment for co-exposure to coal tar. The results for cancer of the head and neck were similar to those of lung cancer, although they were based on a smaller number of deaths. There was no clear suggestion of an association with bitumen fume for any other neoplasm.


CONCLUSIONS
The results of the analysis by bitumen fume exposure do not allow us to conclude on the presence or absence of a causal link between exposure to bitumen fume and risk of cancer of the lung and the head and neck.
Boffetta
Paolo
P
Unit of Environmental Cancer Epidemiology, International Agency for Research on Cancer, Lyon, France. boffetta@iarc.fr
Burstyn
Igor
I
Partanen
Timo
T
Kromhout
Hans
H
Svane
Ole
O
Langård
Sverre
S
Järvholm
Bengt
B
Frentzel-Beyme
Rainer
R
Kauppinen
Timo
T
Stücker
Isabelle
I
Shaham
Judith
J
Heederik
Dick
D
Ahrens
Wolfgang
W
Bergdahl
Ingvar A
IA
Cenée
Sylvie
S
Ferro
Gilles
G
Heikkilä
Pirjo
P
Hooiveld
Mariëtte
M
Johansen
Christoffer
C
Randem
Britt G
BG
Schill
Walter
W
D000328:Adult; D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D005060:Europe / Q000453:epidemiology; D006801:Humans; D006838:Hydrocarbons; D019570:Inhalation Exposure / Q000706:statistics & numerical data*; D008175:Lung Neoplasms / Q000209:etiology / Q000401:mortality; D008297:Male; D009369:Neoplasms / Q000209:etiology / Q000401:mortality*; D009784:Occupational Diseases / Q000209:etiology / Q000401:mortality*; D016273:Occupational Exposure / Q000706:statistics & numerical data*; D018570:Risk Assessment
D006838:Hydrocarbons; C006647:asphalt