Lorry drivers and other workers exposed regularly to vehicle exhaust fumes are at greater risk of contracting bladder cancer, a US study found. Researchers investigated about 2,000 cases of bladder cancer in men and attempted to identify associations with their work. “Our findings indicated that males usually employed as truck drivers or deliverymen have a statistically significant, 50 per cent increase in risk of bladder cancer,” the study found. “Overall, a statistically significant trend in risk with increasing duration of truck driving was observed. This trend was particularly consistent for drivers first employed at least 50 years prior to diagnosis. Of these, truck drivers employed 25 years or more experienced a 120 per cent increase in risk. Elevations in risk were also suggested for taxicab and bus drivers.” In June 2012, IARC rated diesel exhaust fume as a group 1 human carcinogen.
A US study of over 7,000 women union members in the meat industry found that those working in supermarket meat departments had a 3-fold increased risk of death from myeloid leukaemia and non-Hodgkin’s lymphoma. These women, together with women employed in chicken slaughtering factories and meat-packing plants (slaughterhouses), also had a greater risk of lung cancer than those employed in non-meat work. The authors note: “The findings need to be confirmed, but the excess of lung cancer we observed is consistent with reports of an excess of lung cancer in butchers and meatcutters from the analysis of national statistics over different periods in England and Wales, Denmark and Sweden, and also from other studies.”
US researchers who investigated the increased risk of lung cancer in workers exposed to chromium VI found that those most at risk, with over three times the risk of dying from the disease, were those who had worked longer in the plants. The authors said this was probably due to their higher cumulative exposure. Because of this, they suggested exposure limits were insufficiently protective, as they didn’t take account of this cumulative effect, noting “these results suggest a potential excess risk of death from lung cancer among US workers exposed to the current permissible exposure limit (PEL) for hexavalent chromium.”
A German research paper described four case of the asbestos cancer mesothelioma in brake mechanics. The cancer had been caused by asbestos dust, a component of brake (and clutch) linings. In 2014, the asbestos industry was still disputing this link.
Two studies have found excesses of cancers in people working with cadmium. Workers at a Colorado cadmium smelting plant were fund to have double the expected death rate from lung cancer. They noted: “A statistically significant dose-response relationship was observed between lung cancer mortality and cumulative exposure to cadmium.” This was despite a mandatory respirator programme and improvements in ventilation during the period covered by the study. A second study at a British cadmium-nickel battery plant showed increases in both lung and prostate cancers. While the findings were not statistically significant, the authors conclude there is a definite link between cadmium exposures and death from lung and prostate cancers. The paper notes: “A combination of all the available data from the most recent follow up of causes of death among cadmium workers in six different cohorts shows 28 cases of prostatic cancer (SMR = 162) and 195 cases of lung cancer (SMR = 121). This new analysis suggests that long term, high level exposure to cadmium is associated with an increased risk of cancer.”
A study of cause of death among 6,678 rubber production workers whose exposure to 25 solvents could be traced confirmed a cancer association. Exposure to carbon tetrachloride, xylene, carbon disulphide, ethyl acetate, acetone and hexane was related to increases in leukaemia and lymphosarcoma. Workers exposed to carbon tetrachloride had a 15 times greater risk and those exposed to carbon disulphide had a nine times greater risk of dying of leukaemia. In an earlier study the same group of workers were found to have increased deaths from stomach and prostate cancer, but these were not found to be related to solvent exposure.
A study have found a high risk of lung and kidney cancers in workers in the drycleaning and laundry industries. The Oklahoma study of 440 workers identified the solvent perchloroethylene as a key suspect. “Results did not show an overall increase in total cancer, but an elevated risk was found for homicide, lung cancer, and kidney cancer.” It comes after two previous US studies identified a similar link to kidney cancer.
A review of other 20 scientific studies has led the International Agency for Research on Cancer (IARC) has concluded there is ‘limited evidence’ that foundry work causes lung cancer. All the studies showed a raised risk of lung cancer compared to the general population – most were significantly higher, at between 1.5 and 2.5 times the expected level.
A study of over 10,000 steel foundry workers in England has found a significant increase in lung cancer and chronic bronchitis. The study found: “Mortality from lung cancer was significantly raised among workers employed in the foundry and fettling shop areas (standardized mortality ratios 142 and 173, respectively). Most occupational categories in these two areas had more lung cancer deaths than expected, but the standardized mortality ratios were the largest for the furnace bricklayers, fettlers, and heat treatment furnacemen. There was some evidence of risk increasing with length of employment.” The lung cancer risk appeared to have increased over the preceding 30 years, while the chronic bronchitis risk had fallen.
A study of the cause of death of 419 cement workers from north Kent, England, who died between 1948 and 1981 found an excess of stomach cancers. The analysis of death certificates found an almost two fold greater death rate from stomach cancer. In the group that packed and loaded cement there was a stomach cancer rate more than three times the expected level. The paper did not consider work practices, exposure levels or possible preventive measures.
A continually-updated, annotated bibliography of occupational cancer research produced by Hazards magazine, the Alliance for Cancer Prevention and the International Trade Union Confederation (ITUC).
