An assessment of the possible extent of confounding in epidemiological studies of lung cancer risk among roofers

Journal Article · Sun Jul 01 04:00:00 EDT 2007 · Journal of Occupational and Environmental Hygiene

DOI:https://doi.org/10.1080/15459620701354382· OSTI ID:20939743

Mundt, D J; van Wijngaarden, E; Mundt, K A ^[1]

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1. ENVIRON International Corp., Amherst, MA (United States)

We evaluated the likelihood and extent to which the observed increased risk of lung cancer may be due to confounding (a mixing of effects of multiple exposures) by co-exposure to other potential carcinogens present in roofing or to lifestyle variables. We conducted a review of the epidemiological and industrial hygiene literature of asphalt-exposed workers. Peer-reviewed epidemiological studies of asphalt fumes, related occupational exposures, and confounding factors were identified from MEDLINE (1966 early 2004). Industrial hygiene studies of asphalt workers were identified through MEDLINE, publicly available government documents, and asphalt industry documents. Using well established statistical methods, we quantified the extent to which lung cancer relative risk estimates among roofers reflect confounding from other exposures, using different prevalence and risk scenarios. The relative risk of lung cancer varied from 1.2 to 5.0 in 13 epidemiological studies of roofers; most studies reported a relative risk between 1.2 and 1.4. Smoking, asbestos and coal tar were the most likely confounders, but the prevalence of these factors varied over time. The results of the study indicate that much of the observed risk reported in epidemiological studies of cancer among roofers is well within the range of what may have resulted from confounding by reasonable and expected levels of smoking, asbestos or coal tar. This may be particularly true for those studies that did not adjust for these confounders and where the exposure was defined as employment in the roofing industry. In addition to poorly defined asphalt exposure, uncontrolled confounding cannot reliably be ruled out in studies of lung cancer among asphalt-exposed roofers. Therefore, it is not possible to conclude whether roofers are at increased risk of lung cancer due to asphalt exposure.

• OSTI ID: 20939743
• Journal Information: Journal of Occupational and Environmental Hygiene, Journal Name: Journal of Occupational and Environmental Hygiene Journal Issue: 4; ISSN 1545-9624
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
AEROSOLS
ASBESTOS
ASPHALTS
BUILDERS
COAL TAR
EPIDEMIOLOGY
HEALTH HAZARDS
LUNGS
NEOPLASMS
OCCUPATIONAL EXPOSURE
PERSONNEL
RISK ASSESSMENT
TOBACCO SMOKES