Occupational exposure to rock wool and glass wool and risk of cancers of the lung and the head and neck: a systematic review and meta-analysis.
OBJECTIVE
To conduct a review and meta-analysis of risks of cancers of the lung and head and neck (HN) from exposure to rock wool (RW) and glass wool (GW).


METHODS
We performed a systematic review and meta-analysis of risk estimates of lung and HN cancer in epidemiologic studies of workers exposed to man-made vitreous fibers (MMVF), specifically RW and GW.


RESULTS
Sixteen estimates of lung cancer risk yielded a summary relative risk (RR) of 1.21 (95% CI = 1.11 to 1.32, based on 1662 exposed cases). Corresponding RRs were 1.26 (95% CI = 1.10 to 1.44) in studies of production workers (with similar risk for RW and GW workers), 1.06 (95% CI = 0.77 to 1.48) in studies of end users, and 1.18 (95% CI = 0.98 to 1.42) in community-based studies. The summary RR for HN cancer was 1.36 (95% CI = 1.13 to 1.63, 414 exposed cases). With a few exceptions, all studies that assessed the risk of lung or HN cancer according to various indices of MMVF exposure failed to detect a dose-risk relation. There was limited evidence of a confounding effect of tobacco smoking. No clear excess of pleural mesothelioma has been reported in MMVF-exposed workers.


CONCLUSIONS
Despite a small elevation in RR for lung cancer among MMVF production workers, the lack of excess risk among end users, the absence of any dose-risk relation, the likelihood of detection bias, and the potential for residual confounding by smoking and asbestos exposure argue against a carcinogenic effect of MMVF, RW, or GW at this time. Similar conclusions apply to HN cancer risk among workers exposed to MMVF.
Lipworth
Loren
L
International Epidemiology Institute, Rockville, MD 20850, USA. loren@iei.us
La Vecchia
Carlo
C
Bosetti
Cristina
C
McLaughlin
Joseph K
JK
D000328:Adult; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005260:Female; D006258:Head and Neck Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D019016:Mineral Fibers / Q000009:adverse effects*; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D016273:Occupational Exposure / Q000009:adverse effects*; D016272:Occupational Health; D018570:Risk Assessment; D016019:Survival Analysis; D014481:United States
D019016:Mineral Fibers