Occupational and environmental medicine
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Falling asleep while driving accounts for a considerable proportion of vehicle accidents under monotonous driving conditions. Many of these accidents are related to work--for example, drivers of lorries, goods vehicles, and company cars. Time of day (circadian) effects are profound, with sleepiness being particularly evident during night shift work, and driving home afterwards. Circadian factors are as important in determining driver sleepiness as is the duration of the drive, but only duration of the drive is built into legislation protecting professional drivers. Older drivers are also vulnerable to sleepiness in the mid-afternoon. Possible pathological causes of driver sleepiness are discussed, but there is little evidence that this factor contributes greatly to the accident statistics. Sleep does not occur spontaneously without warning. Drivers falling asleep are unlikely to recollect having done so, but will be aware of the precursory state of increasing sleepiness; probably reaching a state of fighting off sleep before an accident. Self awareness of sleepiness is a better method for alerting the driver than automatic sleepiness detectors in the vehicle. None of these have been proved to be reliable and most have shortcomings. Putative counter measures to sleepiness, adopted during continued driving (cold air, use of car radio) are only effective for a short time. The only safe counter measure to driver sleepiness, particularly when the driver reaches the stage of fighting sleep, is to stop driving, and--for example, take a 30 minute break encompassing a short (< 15 minute) nap or coffee (about 150 mg caffeine), which are very effective particularly if taken together. Exercise is of little use. ⋯ More education of employers and employees is needed about planning journeys, the dangers of driving while sleepy, and driving at vulnerable times of the day.
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To describe the epidemiology of carbon monoxide (CO) poisoning in a defined population, identifying those at greatest risk from acute poisoning resulting in admission to hospital or death. ⋯ Elderly people and the very young are at the greatest risk from non-intentional CO poisoning and rates are highest in the winter months. Although deaths from non-intentional CO poisoning are declining nationally, in the West Midlands they have remained stable and hospital admissions are increasing. It is not solely an urban phenomenon with rates for non-intentional CO poisoning and suicides higher in the rural districts. Health authorities need to consider all populations in any prevention programme. Further work is needed to establish the extent of the burden of chronic CO poisoning and the impact of catalytic converters on suicides.
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To better understand the relations between occupational exposure, blood antioxidant enzyme activities, total plasma antioxidant concentration, and the severity of coal workers' pneumoconiosis (CWP). ⋯ These results are in good agreement with the hypothesis that production of reactive oxygen species may be an important event in the exposure to coal mine dusts and the severity of CWP. Erythrocyte catalase and Cu++/Zn++ SOD activities are more closely related to recent exposure to high dust concentrations than to cumulative exposure, and could be considered as biological markers of exposure rather than as markers of early adverse biological effect.
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To assess the short term effect of concentrations of black smoke, sulphur dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3) in ambient air on emergency room visits for asthma in the city of Valencia, Spain during the period 1994-5. ⋯ Current concentrations of ambient air pollution in Valencia are significantly associated with emergency room visits for asthma. This association is high and more consistent for NO2 and O3 than for particulate matter and SO2 (classic pollutants).
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To analyse factors that determine the occurrence of sickness absence due to musculoskeletal problems and the time it takes to return to work. ⋯ Complaints of the neck or shoulder and upper extremities in the 12 months before the study were associated with sickness absence for these complaints during the follow up. Workers with absence due to pain from back, neck or shoulder, upper extremities, or lower extremities were at higher risk of subsequent sickness absence in the next year.