Increased risk for lung cancer and for cancer of the gastrointestinal tract among Geneva professional drivers.

A historical prospective cohort study of 6630 drivers from the Canton of Geneva was carried out to evaluate mortality and incidence of cancer in this occupation. The study population was all men (of all vocations) who held in 1949 a special licence for driving lorries, taxis, buses, or coaches and all new licence holders in the period 1949-61. Men born before 1900 and those with only an ordinary driving licence were excluded. According to the occupation registered on their licence, the 6630 drivers were distributed into three groups: (1) professional drivers (n = 1726), (2) non-professional drivers "more exposed" to exhaust gas and fumes (this group included occupations such as vehicle mechanic, policeman, road sweeper; n = 712), and (3) non-professional drivers "less exposed," composed of all other occupations (n = 4192). The cohort was followed up from 1949 to December 1986 and the trace of 197 men (3%) was lost. Compared with the general population of the Canton of Geneva, professional drivers experienced significant excess risks, taking into account 15 years of latency, for all causes of death (standardised mortality ratio (SMR) 115, 90% confidence interval (90% CI) 107-123) and for all malignant neoplasms (SMR 125, 90% CI 112-140; standardised incidence ratio (SIR) 128, 90% CI 115-142). Cause specific analysis showed significant excesses for lung cancer (SMR 150, 90% CI 123-181; SIR 161, 90% CI 129-198), oesophageal cancer (SMR 183, 90% CI 108-291), stomach cancer (SMR 179, 90% CI 117-263; SIR233, 90% CI 156-336), rectal cancer (SMR 258, 90% CIU 162-392; SIR 200, 90% CI 127-300), and cirrhosis of the liver (SMR 145, 90% CI 104-198). Risk of lung cancer increased significantly with time from first exposure. Among non-professional drivers no significant excess risk was found except for lung cancer mortality among the "less exposed" group (SMR 121, 90% CI 103-140), and for incidence of lung cancer among the "more exposed" group (SIR 161, 90% CI 111-227). The possible casual relation between exposure to engine exhaust emissions and the increased risk for lung cancer and for cancer of the gastrointestinal tract found among professional drivers is discussed.     

Increased risk for lung cancer and for cancer of the gastrointestinal tract among Geneva professional drivers.

A historical prospective cohort study of 6630 drivers from the Canton of Geneva was carried out to evaluate mortality and incidence of cancer in this occupation. The study population was all men (of all vocations) who held in 1949 a special licence for driving lorries, taxis, buses, or coaches and all new licence holders in the period 1949-61. Men born before 1900 and those with only an ordinary driving licence were excluded. According to the occupation registered on their licence, the 6630 drivers were distributed into three groups: (1) professional drivers (n = 1726), (2) non-professional drivers "more exposed" to exhaust gas and fumes (this group included occupations such as vehicle mechanic, policeman, road sweeper; n = 712), and (3) non-professional drivers "less exposed," composed of all other occupations (n = 4192). The cohort was followed up from 1949 to December 1986 and the trace of 197 men (3%) was lost. Compared with the general population of the Canton of Geneva, professional drivers experienced significant excess risks, taking into account 15 years of latency, for all causes of death (standardised mortality ratio (SMR) 115, 90% confidence interval (90% CI) 107-123) and for all malignant neoplasms (SMR 125, 90% CI 112-140; standardised incidence ratio (SIR) 128, 90% CI 115-142). Cause specific analysis showed significant excesses for lung cancer (SMR 150, 90% CI 123-181; SIR 161, 90% CI 129-198), oesophageal cancer (SMR 183, 90% CI 108-291), stomach cancer (SMR 179, 90% CI 117-263; SIR233, 90% CI 156-336), rectal cancer (SMR 258, 90% CIU 162-392; SIR 200, 90% CI 127-300), and cirrhosis of the liver (SMR 145, 90% CI 104-198). Risk of lung cancer increased significantly with time from first exposure. Among non-professional drivers no significant excess risk was found except for lung cancer mortality among the "less exposed" group (SMR 121, 90% CI 103-140), and for incidence of lung cancer among the "more exposed" group (SIR 161, 90% CI 111-227). The possible casual relation between exposure to engine exhaust emissions and the increased risk for lung cancer and for cancer of the gastrointestinal tract found among professional drivers is discussed.     

Increased risk of lung cancer among male professional drivers in urban but not rural areas of Sweden.

OBJECTIVES: To study the risk of lung cancer in different subgroups of professional drivers in urban and rural areas of Sweden. METHODS: Information on occupation and geographical region was obtained from the Swedish census of 1970 and data on the incidence of lung cancer between 1971 and 1984 from the National Swedish Cancer Registry. Professional drivers were separated into bus, taxi, and long and short distance lorry drivers. Comparisons of cumulative incidence of lung cancer were made between each particular group of drivers and gainfully employed men in the same region. RESULTS: Taxi drivers, and long and short distance lorry drivers in Stockholm County showed increased relative risks (RRs) of lung cancer with the highest risk among the short distance lorry drivers (RR 2.0, 95% confidence interval (95% CI) 1.5 to 2.6). These categories of drivers also showed increased risks in the other two large conurbations in Sweden. In the rest of the country (mainly rural areas) there were no increased RRs for any category of driver. The RR for bus drivers was not increased in any region. After adjustment for assumed differences in smoking habits the RRs remained significantly increased for lorry drivers in Stockholm but not for other groups of drivers in other areas. However, the RRs remained numerically higher in large conurbations than in rural regions for all groups of drivers. CONCLUSIONS: These findings suggest that some factors present in the urban environment play a substantial part in the excess of lung cancer among short distance lorry drivers in urban areas of Sweden. Exposure to motor exhaust fumes may have contributed to this excess.     

Stroke among male professional drivers in Denmark, 1994-2003

Objectives

(1) To estimate the relative risk of stroke among various groups of professional drivers; (2) to determine if any excess risk should be attributed to infarction or haemorrhage; (3) to estimate the relative risk ratio for stroke among professional drivers living in Greater Copenhagen compared to those living outside the metropolis.

Methods

A cohort of 6285 bus drivers, 4204 car, taxi, and van drivers, and 25 879 heavy truck and lorry drivers were followed up for hospital admission due to stroke and sub‐diagnoses in the period 1994–2003. Using hospital admission for all economically active men as the standard, the standardised hospitalisation ratios (SHR) were calculated, taking age and county into consideration.

Results

There was a high SHR for stroke among all groups of professional drivers (SHR = 132; 95% CI 121–141). Among car, taxi, and van drivers the SHR was 157 (95% CI 132–189), among bus drivers it was 139 (95% CI 119–163), and among heavy truck and lorry drivers it was 124 (95% CI 113–136). The excess risk for all groups of professional drivers was highest for cerebrovascular infarction (SHR = 139; 95% CI 124–155) and lowest for non‐traumatic intracranial haemorrhage (SHR = 113; 95% CI 96–133). The excess risks for all groups were significantly higher for cerebrovascular infarction than for non‐traumatic intracranial haemorrhage (relative risk ratio (RRR) 1.23; 95% CI 1.01–1.51). The RRR of stroke among drivers in the metropolitan area compared to rural areas was 1.13 (95% CI 0.94–1.36). The RRR for stroke among car, taxi, and van drivers compared to drivers of heavy trucks and of lorries was 1.28 (95% CI 1.03–1.57).

Conclusion

All groups of professional drivers are at increased risk of stroke. The excess risk is more due to cerebral infarctions than to non‐traumatic intracranial haemorrhage. The risk of stroke is higher among drivers carrying passengers than among drivers carrying goods.     

Increased cancer risk among relatives of nonsmoking lung cancer cases

Lung cancer has been shown to aggregate in families of nonsmoking lung cancer cases with an earlier age at onset. The current study evaluates whether relatives of nonsmoking lung cancer cases are at increased risk of cancers at sites other than lung. Families were identified through 257 population‐based, nonsmoking lung cancer cases and 277 population‐based, nonsmoking controls residing in metropolitan Detroit. Data were collected for 2,252 relatives of cases and 2,408 relatives of controls. First‐degree relatives of nonsmoking lung cancer cases were at 1.52‐fold (95% CI, 1.02–2.27) increased risk of cancer of the digestive system after adjustment for each relative's age, race, sex, and smoking status. Relative risk estimates also were elevated, but not significantly, for tobacco‐related cancers (RR = 1.39) and breast cancer (RR = 1.72). Among first‐degree relatives of younger probands (age 40–59), risk was non‐significantly increased 72% (95% CI 0.95–3.10) for all cancers combined and 3.14‐fold for cancers of the digestive system (95% CI 0.76–12.9). Nonsmoking relatives of cases were at increased risk of all cancer sites combined (RR = 1.32; 95% CI 1.003–1.73), cancers other than lung (RR = 1.37; 95% CI 1.03–1.82), and digestive system cancers (RR = 2.01; 95% CI 1.20–3.37). These findings of moderate familial aggregation for cancers of the lung, digestive system, breast, and tobacco‐related sites suggest that common susceptibility genes may act to increase risk for a variety of cancers in families. Genet. Epidemiol. 17:1–15, 1999. © 1999 Wiley‐Liss, Inc.     

Increased familial risk for non-lung cancer among relatives of lung cancer patients

Reports of two or more anatomically distinct cancer types clustering in families suggest the possible existence of a susceptibility-to-cancer gene. To determine whether a genetic predisposition accounts for such familial aggregation, a retrospective case-control study was conducted in 1976-1979 of 337 southern Louisiana families in each of which a deceased lung cancer patient was used as the proband. A comparison of first-degree relatives of proband families with spouse (control) families revealed a significantly greater overall risk of cancer (odds ratio (OR) = 2.0, p less than 0.0001) in the proband group. Using logistic regression techniques to control for the confounding effects of age, sex, cigarette smoking, and occupational/industrial exposures, relatives of lung cancer probands maintained an increased risk of non-lung cancer (p less than 0.05). The crude odds ratio of a proband family having one family member with cancer was 1.67 compared with control families. Proband families were 2.16 times more likely to have two other family members with cancer. For three cancers and four or more cancers, the risk increased to 3.66 and 5.04, respectively. Each risk estimate was significant at the 0.01 level. The most striking differences in cancer prevalence between proband and control families were noted for cancer of the nasal cavity/sinus, mid-ear, and larynx (OR = 4.6); trachea, bronchus and lung (OR = 3.0); skin (OR = 2.8); and uterus, placenta, ovary, and other female organs (OR = 2.1). These data support the hypothesis of a genetic susceptibility to cancer in families with lung cancer.     

Mortality among professional drivers

The mortality of truck drivers and taxi drivers was studied in Reykjavík. The national mortality rate was used for comparison, and the follow-up lasted until 1 December 1988. The 868 truck drivers (28,788.0 person-years) had an excess of lung cancer deaths [24 observed, 11.2 expected, standardized mortality ratio (SMR) 2.14], but fewer deaths than expected from respiratory diseases (15 observed versus 30.1 expected). The SMR from lung cancer did not steadily increase as the duration of employment increased, nor did it change with the length of follow-up. The SMR values did not deviate substantially from unity for the taxi drivers. Since the high mortality from lung cancer among the truck drivers did not seem to be due to their smoking habits, it might have been caused by one or more occupational factors, especially in light of this group's exposure to engine exhaust gases.     

Hospital admissions among male drivers in Denmark

OBJECTIVES—To facilitate decisions about interventions and to establish baseline values for future evaluation of preventive efforts, the aim of the present study was to elucidate the disease pattern among male professional drivers in Denmark. The study differentiated between drivers of goods vehicles and drivers of passenger transport.
METHODS—Cohorts of all 20-59 year old Danish male professional drivers in the years 1981, 1986, 1991, and 1994 were formed, to calculate age standardised hospital admission ratios (SHRs) and time trends (1981-97) for many diagnostic aggregations.
RESULTS—SHRs for diseases in practically all systems and organs of the body were higher among professional drivers than they were in the male working population at large. Also drivers of passenger transport, compared with drivers of goods vehicles, had significantly high SHRs due to infectious and parasitic diseases, diseases of the circulatory system, and diseases of the respiratory system, and significantly lower rates of injury. For both driver groups, the SHRs for acute myocardial infarction increased with time whereas the SHR for acute gastritis decreased, and for drivers of passenger transport an increasing SHR for chronic obstructive pulmonary disease, was found over time.
CONCLUSION—Drivers of passenger transport and drivers of goods vehicles differ in their disease patterns. The results support the hypothesis that preventive efforts are needed in both groups, but underline that different strategies are required for different categories of drivers.


Keywords: professional drivers; hospital admissions; surveillance system     

Myocardial infarction among professional drivers

BACKGROUND: Professional drivers are at an increased risk of myocardial infarction but the underlying causes for this increased risk are uncertain. METHODS: We identified all first events of myocardial infarction among men age 45-70 years in Stockholm County for 1992 and 1993. We selected controls randomly from the population. Response rates of 72% and 71% resulted in 1067 cases and 1482 controls, respectively. We obtained exposure information from questionnaires. We calculated odds ratios (ORs), with and without adjustment for socioeconomic status, tobacco smoking, alcohol drinking, physical inactivity at leisure time, overweight status, diabetes and hypertension. RESULTS: The crude OR among bus drivers was 2.14 (95% confidence interval = 1.34-3.41), among taxi drivers 1.88 (1.19-2.98) and among truck drivers 1.66 (1.22-2.26). Adjustment for potential confounders gave lower ORs: 1.49 (0.90-2.45), 1.34 (0.82-2.19) and 1.10 (0.79-1.53), respectively. Additional adjustment for job strain lowered the ORs only slightly. An exposure-response pattern (by duration of work) was found for bus and taxi drivers. CONCLUSIONS: The high risk among bus and taxi drivers was partly explained by unfavorable life-style factors and social factors. The work environment may contribute to their increased risk. Among truck drivers, individual risk factors seemed to explain most of the elevated risk.     

Peptic ulcer among urban bus drivers in Denmark

As part of a survey on the work environment of bus drivers, 2045 (83%) of 2465 male bus drivers in the three major cities in Denmark in 1978 answered a postal questionnaire on health and working conditions. In order to evaluate the relative occurrence of peptic ulcer among the bus drivers, a follow-up study was also conducted. All hospital discharges with a peptic ulcer diagnosis among the bus drivers were registered from the Danish National Patient Register. All Danish men were used as reference group. On the basis of the 1978-questionnaire association between occupational and psychosocial factors and subsequent hospital discharge with a peptic ulcer diagnosis was studied. The prevalence of abdominal pain alleviated by food intake was 12% among bus drivers and 6% in the reference group. The incidence of hospital discharge with duodenal ulcer among younger bus drivers was twice the incidence among Danish men in the same age group. The incidence of all manifestations of peptic ulcer disease among bus drivers did not differ from the incidence among Danish men. Of occupational and psycho-social factors, wage dissatisfaction and smoking showed statistically significant association with hospital discharge with PU in a 6 3/4-year period. Job dissatisfaction, stress symptoms and lack of some social network factors tended to increase the risk of hospital discharge with PU.     

Cancer incidence among urban bus drivers in Denmark

Summary During the period from 1978–1984 the incidence of cancer among 2465 male urban bus drivers in three major cities in Denmark was studied. The information with regard to cancer diagnosis was obtained from the Danish Cancer Registry. Danish men in 1981 were used as reference. Standardized Morbidity Ratio (SMR) for bladder- and skin cancer was significantly elevated among the bus drivers with values of 206 and 202, respectively. As to other cancers, no significant deviations from the expected were found. The same result was found when only drivers with more than ten years' seniority were included in the calculations. The incidence of skin cancer remained significantly elevated when corrected for degree of urbanization. Traffic density and whether the drivers worked in Copenhagen or in the province were not related to cancer incidence.     

Low back trouble among urban bus drivers in Denmark

The occurrence of low back trouble and possible connection with psychosocial conditions among urban bus drivers were studied using a questionnaire and subsequent registration of hospital discharges. 2,045 (83%) full-time male bus drivers in the three largest cities in Denmark answered a questionnaire in 1978 regarding psychosocial factors and health. The prevalence of frequent low back pain was 57%. In a control group of 195 motormen the prevalence was 40%. Standardized Morbidity Ratio for bus drivers discharged from hospital during the period 1978-1984 with the diagnosis lumbar disc herniation was 137 compared to all Danish men. These differences were statistically significant. Of psychosocial factors only "the feeling of being mentally unbalanced" was found to be statistically significantly related to subsequent hospital discharge with a LBT-diagnosis. Long seniority as bus driver of those discharged from hospital with LBT makes it probable that LBT has etiologic factors in the work environment. The sedentary position and whole-body vibrations may be contributory causes.     

Increased cancer risk among surgeons in an orthopaedic hospital

BACKGROUND: Five cancer cases over 7 years were reported in a small orthopaedic hospital where radiation protection practice was poor. AIM: To investigate whether workers subject to routine radiation dosimetric assessment in that hospital had an increased cancer risk. METHODS: One hundred and fifty-eight workers subject to routine dose assessment and 158 age-sex-matched unexposed workers were questioned about cancer occurrence. All tumours were analysed as a single diagnostic category. RESULTS: Cumulative 1976-2000 cancer incidence was 29 (9/31), 6 (8/125) and 4% (7/158) in orthopaedics, exposed other than orthopaedics, and unexposed workers, respectively. At logistic regression analysis, working as orthopaedic surgeon significantly (P<0.002) increased the risk of tumours. CONCLUSION: These findings caution against surgeons' underestimation of the potential radiation risk and insufficient promotion of safe work practices by their health care institutions.     

Locomotor diseases among male long-haul truck drivers and other professional drivers

Objective High risks for locomotor diseases have been reported for bus and truck drivers in general; however, little is known about the specific risks of long-haul truck drivers. Methods Standardised hospitalisation ratios (SHR) for different locomotor diseases of bus drivers, long-haul truck drivers and other truck drivers were compared with each other and with the general Danish working population. Results Intervertebral disc disorders were more common among professional drivers (SHR: 119, 95% CI: 114–125) and of similar magnitude for cervical and non-cervical disorders. Both long-haul truck drivers and bus drivers had higher SHR for intervertebral disc disorders (SHR: 133, 95% CI: 114–155/SHR: 141, 95% CI: 129–154, respectively) than other truck drivers (SHR: 109, 95% CI: 102–116). The SHR for carpal tunnel syndrome was high among long-haul drivers (SHR: 163, 95% CI: 101–249) and for other truck drivers (SHR: 130, 95% CI: 108–156) compared to bus drivers (SHR: 110, 95% CI: 79–149). All drivers had high SHR for lesions of the ulnar nerve (SHR: 159, 95% CI: 119–207), especially bus drivers (SHR: 197, 95% CI: 116–311). Long-haul truck drivers had high SHRs for synovitis and bursitis (SHR: 150, 95% CI: 105–207), in contrast to other truck drivers and bus drivers (SHR: 103, 95% CI: 89–120/SHR: 87, 95% CI: 66–112, respectively). Conclusion All groups of professional drivers experience high risk of various disorders of the locomotor system but type of vehicle and specific working conditions are associated with different health effects on the locomotor system.     

A mortality study of lung cancer among swiss professional drivers: Accounting for the smoking related fraction by a multivariate approach

Summary The mortality due to lung cancer among chauffeurs', who have a presumably long-term exposure to diesel exhaust fumes, was analysed. As controls, men in industrial occupations of similar socio-economic status were selected. Cases were drawn from the Swiss mortality register for the years 1979–1983. Person-years were obtained using data from the 1980 census records. These two data files were combined by occupation, age class and socio-economic status. Age adjusted incidence rates were calculated applying Poisson regression. To control for tabacco related lung cancer mortality an indirect adjustment was undertaken. Using information about the smoking habits of the people in the occupations under study, smoking-attributable lung cancer mortality was accounted for by incorporating Axelson's technique into multivariate regression modeling. The mortality ratio for lung cancer for chauffeurs with respect to the controls was 2.27, which is significantly in excess of 1.95% Cl (1.99, 2.58). Other tobacco related diagnoses such as bladder cancer, esophagal cancer and ischemic heart diseases showed excess risks as well. After accounting for smoking, a slight but significant increase in lung cancer mortality remained among chauffeurs (mortality ratio 1.48, 95% Cl: 1.30, 1.68). In summary, the present results do support the hypothesis that diesel exhaust is a significant cause of lung cancer.

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Zusammenfassung Die Sterblichkeit an Lungenkrebs bei Schweizer Chauffeuren wurde analysiert, um die Hypothese der kanzerogenen Wirkung von Diesel-Abgasen zu untersuchen. Es wurde angenommen, dass Chauffeure durch ihre berufliche Tätigkeit langzeit-exponiert gegenüber Diesel-Abgasen sind. Als Kontrollen wurden Berufe aus verschiedenen industriellen Bereichen mit ähnlichem sozio-ökonomischem Status verwendet. Die Todesfälle wurden anhand der Schweizerischen Sterbestatistik im Zeitraum 1979–1982 erhoben Daten der Volkszählung von 1980 wurden benutzt, um bevölkerungsbezogene Risiken zu berechnen. Altersstandardisierte Raten wurden mit log-linearen Poisson-Regressionsmodellen gerechnet. Die Sterblichkeit an Lungenkrebs bedingt durch Tabakkonsum wurde auf indirekte Art korrigiert, indem Angaben zum Raucherverhalten der untersuchten Berufe berücksichtigt und mit Axelson's Methode in das Poisson-Modell integriert wurden. Das relative Risiko (RR) für Lungenkrebs bei Chauffeuren in Bezug zur Vergleichsgruppe beträgt 2.27. Die Erhöhung ist signifikant (95%-Vertrauensintervall: 1.99–2.58). Andere rauchenbezogene Diagnosen wie Blasen-und Speiseröhrenkrebs sowie ischämische Herzkrankheiten zeigten ebenfalls erhöhte Risiken. Nach Kontrolle des rauchenbedingten Anteils war die Sterblichkeit an Lungenkrebs immer noch signifikant erhöht, RR: 1.48, 95% VI: 1.30–1.68. Zusammengefasst unterstützen die vorliegenden Resultate die Hypothese, wonach Dieselabgase zu erhöhter Lungenkrebssterblichkeit führen.

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Résumé Afin d'examiner l'hypothèse d'un effet cancérogène des gaz d'échappement des motéurs diesel, les taux de mortalité par cancer du poumon chez les chauffeurs suisses ont été analysés Nous avons supposé que par leurs activités professionelles les chauffeurs étaient exposés à long-terme aux gaz d'échappement des moteurs diesel. Des professions du secteur industriel correspondant à une position socio-économique similaire ont constitué le groupe témoin. Les cas de décès furent tires du régistre suisse de mortalité pour les anneés 1979–1982. Le recensement de 1980 a été utilisé pour calculer le risque de mortalité par rapport à la population générale en éstimant les anneés de personne pour la période 1979–1982. Le risque ajusté en fonction de l'âge a été calculé au moyen de la régression de Poisson (modèle log-linéaire). L'ajustement en fonction du tabagisme a été fait de manière indirecte, en utilisant des données surles habitudes tabagiques des professions incluses dans cette étude et en appliquant la méthode d'Axelson au modèle de régression. Nous avons observé un risque relatif (RR) de déces par cancer du poumon chez les chauffeurs de 2.27 (intervalle de confiance à 95%: 1.99, 2.58). De même, l'analyse des taux de mortalité par des autres affections lieés au tabagisme comme cancer de vessie, cancer de l'oesophage et des maladies ischémiques du coeur a mis en évidence des risques élevés chez les chauffeurs. Après ajustment en fonction du tabagisme, nous avons observé une augmentation faible mais significative de la mortalite par cancer du poumon chez les chauffeurs: RR: 1.48, intervalle de confiance à 95% dl 1.30 à 1.68. En résumé, ces résultats confirment l'hypothèse que les gaz d'échappement des moteurs diesel ont un effet cancérogène.