|
Relation between occupational silica exposure and lung cancer risk
The
aim of this study was to systematically review the large amount of
epidemiological data (28 cohort, 15 case-control and 2 proportionate
mortality ratio studies) on the relation between occupational silica
exposure and lung cancer risk that have been collecting after the
publication, in 1997, of a Monograph from the International Agency for
Research on Cancer (IARC) that classified occupational exposure to
crystalline silica as carcinogenic to humans (Group 1). We
examined different study types separately, and estimated pooled relative
risks of lung cancer of 1.34 from cohort, 1.41 from case-control and 1.24
from proportionate mortality ratio studies that considered occupational
exposure to silica. The association with lung cancer was consistent in
studies of silicotics, moderate for workers with undefined silicosis
status, and absent in studies of non-silicotics (though based on two
investigations only). On the basis of these results as well as the evaluation of single studies which underlines the drawbacks and limitations of most of them, the available data from the last decade leave open the issue as to whether silica per se materially increases lung cancer risk in absence of silicosis. The silicosis-cancer association is now established, in agreement with other studies and meta-analysis.
Bibliographical refernce:
Claudio Pelucchi Istituto di Ricerche Farmacologiche 'Mario Negri', Milano, Italy
|