Lung cancer mortality among European rock/slag wool workers: exposure-response analysis.
OBJECTIVE
The purpose was to analyze the relationship between semi-quantitative indices of exposure to manmade vitreous fibers and lung cancer mortality among European rock/slag wool (RSW) workers.


METHODS
The study population comprised 9,603 male workers employed in RSW production in seven factories in Denmark, Norway, Sweden, and Germany, followed up for mortality as of 1990-91. Estimates of past exposure to respirable fibers were used to calculate cumulative exposure with a 15-year lag and maximum annual exposure based on employment history up to 1977. Rate ratios were estimated via multivariate Poisson regression, adjusting for country, age, calendar year, time since first employment, and employment status.


RESULTS
A total of 159 lung cancer deaths were included in the analysis of which 97 among workers with more than one year of employment. We found nonstatistically significant trends in lung cancer risk according to cumulative exposure. Relative risks (RR) in the four quartiles were 1.0 (reference), 1.3 (95 percent confidence interval [CI] = 0.8-2.4), 1.2 (CI = 0.7-2.1), and 1.5 (CI = 0.7-3.0, P test for trend = 0.4). When workers with less than one year of employment were excluded, there was no increased risk; the RRs in the four quartiles were 1.0, 0.9 (CI = 0.4-2.0), 0.8 (CI = 0.3-1.9), and 1.0 (CI = 0.4-2.7). No trend was present according to maximum annual exposure. The results were not consistent among countries.


CONCLUSIONS
We found a positive association between exposure to respirable fibers and lung cancer mortality. However, the lack of statistical significance, the dependence of the results on inclusion of short-term workers, the lack of consistency among countries, and the possible correlation between exposure to respirable fibers and to other agents reduce the weight of such evidence.
Consonni
D
D
University of Milan, Italy.
Boffetta
P
P
Andersen
A
A
Chang-Claude
J
J
Cherrie
J W
JW
Ferro
G
G
Frentzel-Beyme
R
R
Hansen
J
J
Olsen
J
J
Plato
N
N
Westerholm
P
P
Saracci
R
R
D000328:Adult; D017677:Age Distribution; D000368:Aged; D015331:Cohort Studies; D016001:Confidence Intervals; D004784:Environmental Monitoring / Q000379:methods; D062665:Epidemiological Monitoring; D005060:Europe / Q000453:epidemiology; D006801:Humans; D008175:Lung Neoplasms / Q000209:etiology / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D016012:Poisson Distribution; D012307:Risk Factors; D017678:Sex Distribution; D015996:Survival Rate; D013783:Textile Industry