Asbestos Exposure and Cancer Mortality among Petroleum Refinery Workers: A Poisson Regression Analysis of Updated Data

Cancer risk in oil refinery workers: a pooled mortality study in Italy

Background:

Oil refinery workers are exposed to several well-established carcinogens and working in this type of industry has been classified by IARC as probable carcinogen to humans (Group 2A).

Objectives:

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

Methods:

The cohort included 5112 male workers ever employed between 1949 and 2011. The average follow-up period was 49 years. Standardized mortality ratios (SMR) and 95% Confidence Intervals (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 cancer (6 deaths, SMR 1.59; 95% CI 0.71-3.53), brain cancer (14 deaths, SMR 1.47; 95% CI 0.87-2.49) and lymphatic leukemia (LL) (8 deaths, SMR 1.81; 95% CI 0.91-3.62) 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 (and chronic lymphatic leukemia in particular) excess regarded workers with latency and duration longer than 20 years. Four deaths from acute myeloid leukemia (AML) were observed and all occurred after 20 years of latency (SMR 1.55, 95% CI 0.58-4.12); a two-fold-increased risk was observed in the longest duration. No increased risk for skin cancer has been observed in our study population.

Conclusion:

Our findings are consistent with recent evidence of an increased mortality from pleural and hematopoietic malignancies (AML and LL) among oil refinery workers. However, the lack of individual quantitative exposure data and the small number of observed events prevent the identification of the possible causal role of individual chemicals, including benzene, especially at the current very low exposure levels.

Mortality among Coast Guard Shipyard workers: A retrospective cohort study of specific exposures

In a previous analysis of a cohort of shipyard workers, we found excess mortality from all causes, lung cancer, and mesothelioma for longer work durations and in specific occupations. Here, we expand the previous analyses by evaluating mortality associated with 5 chemical exposures: asbestos, solvents, lead, oils/greases, and wood dust. Data were gathered retrospectively for 4,702 workers employed at the Coast Guard Shipyard, Baltimore, MD (1950-1964). The cohort was traced through 2001 for vital status. Associations between mortality and these 5 exposures were calculated via standardized mortality ratios (SMRs). We found all 5 substances to be independently associated with mortality from mesothelioma, cancer of the respiratory system, and lung cancer. Findings from efforts to evaluate solvents, lead, oils/greases, and wood dust in isolation of asbestos suggested that the excesses from these other exposures may be due to residual confounding from asbestos exposure.

Angiotensin receptor blockers and tumorigenesis: something to be (or not to be) concerned about?

The possibility of carcinogenic side effects of antihypertensive therapies due to their chronic administration has been raised multiple times in the past. Recently, the issue has again drawn attention, this time in relation to angiotensin receptor blockers (ARBs). This, among others, caused both American and European drug regulation authorities to review the underlying evidence concerning the relationship between this class of medications and potential adverse carcinogenic outcome. A plethora of both basic science and preclinical evidence has been generated, and three meta-analyses and one nationwide cohort have focused on this specific question. The current review aims to summarize the contemporary multidisciplinary evidence on whether ARBs may be associated with an increased risk of tumorigenesis.

Asbestos-related cancers in refinery workers in the Australian petroleum industry

In this study of the incidence of asbestos-related cancer in the Australian petroleum industry, the authors traced a cohort of 16,543 petroleum industry workers for a total of 226,989 person-years. There were 18 cases of pleural mesothelioma; 12 occurred in refinery nonoffice workers, for whom the Standardized Incidence Ratio was 3.77 (95% confidence interval = 1.95-6.59). The incidence of lung cancer was significantly lower than that in the general male population. Lung cancer incidence was higher in maintenance workers than in nonmaintenance workers, but the excess was not statistically significant, as it was based on small numbers with wide confidence intervals. Lung cancer rates in refinery workers did not increase with duration of employment; however, they did tend to be higher in workers hired in earlier decades. Excess mesothelioma incidence in refinery workers is confirmed, but it is likely that there are few if any asbestos-related lung cancers.