Exposure to occupational carcinogens and lung cancer risk. Evolution of epidemiological estimates of attributable fraction.

BACKGROUND AND AIM OF THE WORK

Lung cancer is the leading cause of cancer death world-wide. Among the possible causes, occupational risk factors play a major role and are potentially preventable. We reviewed the scientific evidence about lung cancer burden due to occupation.

METHODS

We reviewed the literature and selected population case-control and cohort studies which provided estimates of the proportion of lung cancers attributable to occupational carcinogens (population attributable fraction, PAF). Different methods were used to evaluate occupational exposure to suspected/known lung carcinogens: lists of high-risk occupations, job-exposure matrix (JEM), expert assessment. Only studies which adjusted for tobacco smoking were included.

RESULTS

The PAFs reported by the 32 selected Italian and international studies among men vary greatly in time and space: they ranged between 0 to 40% according to different geographical prevalence of hazardous industries (e.g., basic metal industries, shipbuilding and railroad equipment manufacturing). The PAFs estimated using JEM and expert assessment were on average higher. Data for women were usually few and insufficient to calculate stable estimates.

CONCLUSIONS

A significant proportion of lung cancers is attributable to occupational carcinogens. The estimates are extremely variable in time and place and mainly depend on the industrial setting of the area under study; caution is therefore required in generalizing these results to the whole country. Alternative approaches to evaluate occupational lung cancer burden among women are necessary.