Objectives To examine the mortality experience of workers employed in four Italian oil refineries.

Method The cohort included 5112 male workers ever employed between 1949 and 2011. The average follow-up period was 49 years. SMR and 95% CI were calculated using as reference age-gender-calendar specific regional rates. Analyses by duration of employment and latency were performed.

Results In the whole cohort, pleural (6 deaths, SMR 1.59; 95% CI 0.7–3.5), brain cancers (14 deaths, SMR 1.47; 95% CI 0.9–2.5) and lymphatic leukaemia (LL) (8 deaths, SMR 1.81; 95% CI 0.9–3.6) showed increased risks. All pleural cancers occurred after 10 years of latency and the highest risk was observed among workers with duration ≥ 20 years; the brain cancer excess was confined in the shortest duration and latency. The LL excess regarded workers with latency and duration longer than 10 years. Mortality from Non-Hodking lymphoma (NHL) (13 deaths) and acute myeloid leukaemia (AML) did not differ from the expectation. All AML cases (4 deaths) occurred after 20 years of latency (SMR 1.55, 95% CI 0.6–4.1) and a two fold-increased risk was observed in the longest duration. Mortality for NHL + LL (recently classified as subtypes of NHL) showed increased risks among workers with duration and latency longer than 20 years.

Conclusions Our findings confirmed recent epidemiological evidences of an increased risk for pleural cancer and are coherent with most recent meta-analyses suggesting a limited evidence of an increased risk for lymphatic neoplasms in refinery workers possibly due to past exposure to benzene.