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The results support the hypothesis of a causal role of physical workload for the development of back and neck pain. Ergonomic factors partially mediated the risk of back and neck pain associated with driving, suggesting a potential for prevention of back and neck pain by ergonomic redesign of transit vehicles. Elevated risks for back and neck pain for female drivers were not explained by anthropometric and ergonomic factors.

This paper reports the results of a cross-sectional study conducted to evaluate the prevalence of hypertension in 1500 black and white male bus drivers from a large urban transit system in the US. Data for this study were compiled from the files of an occupational health clinic which conducts biennial medical examinations for drivers' license renewal. To test whether prevalence of hypertension was higher among bus drivers than among employed individuals in general, drivers were compared to three groups: individuals from both a national and local health survey and individuals undergoing baseline health examinations prior to employment as bus drivers. After adjustment for age and race, hypertension rates for bus drivers were significantly greater than rates for each of the three comparison groups. These findings support previous results from international studies of bus drivers suggesting that exposure to the occupation of driving a bus may carry increased health risk. This research has expanded into an on-going study which has the goals of clarifying the extent of hypertension in bus drivers and identifying specific behavioural and occupational factors that may be responsible for increased risk of cardiovascular disease.

San Francisco bus drivers have an increased prevalence of hypertension. This study examined relationships between blood lead concentration and blood pressure in 342 drivers. The analysis reported in this study was limited to subjects not on treatment for hypertension (n = 288). Systolic and diastolic pressures varied from 102 to 173 mm Hg and from 61 to 105 mm Hg, respectively. The blood lead concentration varied from 2 to 15 jig/dL The relationship between blood pressure and the logarithm of blood lead concentration was examined using multiple regression analysis. Covariates included age, body mass index, sex, race, and caffeine intake. The largest regression coefficient relating systolic blood pressure and blood lead concentration was 1.8 mm Hg/ln (pg/dL) [90% C. I.,-1.6, 5.31. The coefficient for diastolic blood pressure was 2.5 mm Hg/ln (pg/dL) [90% C. I., 0.1, 4.91. These findings suggest effects of lead exposure at lower blood lead concentrations than those concentrations that have previously been linked with increases in blood pressure.

In this study, data from transit vehicle operators of the San Francisco Municipal Railway (Muni), and a control group of individuals newly hired but not yet working as operators, were used to investigate prevalence of hypertension as a function of exposure to bus driving (years of driving), controlling for alcohol consumption and body mass index. Data were collected from transit vehicle operators in the course of their regular biennial examination during the period November 1983 to October 1985. Groups working as operators fewer than 10 years (n = 1137), from 10 to 20 years (n = 493), and more than 20 years (n = 196) were compared to each other and to a group of individuals with no prior exposure, but who were given a medical examination just before beginning their jobs as transit vehicle operators (n = 226). For hypertension (defined as systolic blood pressure > or = 140, or diastolic blood pressure > or = 90, or taking hypertension medication), the prevalence, adjusted for age, race, and gender, increased in a stepwise fashion from 28.8 percent in the group with no exposure to 38.9 percent in the group of drivers with more than 20 years on the job. A similar pattern was found for moderate to severe hypertension (systolic blood pressure > or = 160, or diastolic blood pressure > or = 95, or hypertension medication). These patterns were diminished, but not eliminated, when body mass index and alcohol consumption were considered. Higher rates of separation from employment for hypertensive operators suggested that the effect of years of employment may be underestimated by this cross-sectional comparison. Prolonged exposure to operating a transit vehicle may be associated with increased hypertension; increased alcohol consumption and body mass index with increased years of driving may account for at least some of the increased hypertension.