Sleep-wake rhythm in an irregular shift system

Sleep in shift work has been studied extensively in regular shift systems but to a lesser degree in irregular shifts. Our main aim was to examine the sleep-wake rhythm in shift combinations ending with the night or the morning shift in two irregular shift systems. Three weeks' sleep/work shift diary data, collected from 126 randomly selected train drivers and 104 traffic controllers, were used in statistical analyses including a linear mixed model and a generalized linear model for repeated measurements. The results showed that the sleep-wake rhythm was significantly affected by the shift combinations. The main sleep period before the first night shift shortened by about 2 h when the morning shift immediately preceded the night shift as compared with the combination containing at least 36 h of free time before the night shift (reference combination). The main sleep period before the night shift was most curtailed between two night shifts, on average by 2.9 and 3.5 h among the drivers and the controllers, respectively, as compared with the reference combination. Afternoon napping increased when the morning or the day shift immediately preceded the night shift, the odds being 4.35-4.84 in comparison with the reference combination. The main sleep period before the morning shift became 0.5 h shorter when the evening shift preceded the morning shift in comparison with the sleep period after a free day. The risk for dozing off during the shift was associated only with the shift length, increasing by 17 and 35% for each working hour in the morning and the night shift, respectively. The results demonstrate advantageous and disadvantageous shift combinations in relation to sleep and make it possible to improve the ergonomy of irregular shift systems.     

公交驾驶员职业倦怠与心理健康状况的关系研究

目的 揭示公交驾驶员职业倦怠和心理健康现状,探索二者之间的关系,为减少公交驾驶员职业倦怠、提高其心理健康水平提供参考。方法 对成都市3个公交公司的995名公交驾驶员采用Maslach职业倦怠量表普适版（MBI-GS）及一般健康问卷（GHQ-12）进行调查。结果 成都市995名公交驾驶员在职业倦怠总分及情绪衰竭、玩世不恭、成就感低落维度上的中位数和四分位数间距分别为2.33(1.58)分、2.40(3.00)分、0.75(2.00)分及2.17(3.00)分,一般心理健康总分的中位数和四分位数间距为11.00(5.00)分。不同学历、锻炼情况驾驶员倦怠总分差异有统计学意义（P＜0.05）,心理健康总分在性别、驾龄及锻炼情况上差异有统计学意义（P＜0.05）。因子分析共提取了自我否定、自我肯定、严重情绪反应3个因子。职业倦怠总分及各维度与一般心理健康总分及各因子间均呈正相关（P＜0.05）,自我否定和严重情绪反应因子对职业倦怠有较好的预测作用。结论 公交驾驶员职业倦怠现象较为严重且存在一定的心理健康问题。心理健康水平可以预测驾驶员的职业倦怠。     

公交车驾驶员冲动性与心理健康的相关性研究

目的：调查公交公司驾驶员的冲动性水平及心理健康水平,并分析二者之间的关系。方法：采用自编人口学调查表、Barratt冲动性量表第11版（BIS-11）、症状自评量表（SCL-90）为研究工具,对266名公交公司驾驶员进行问卷调查。结果：公交车驾驶员的冲动性总分为（53.50±7.54）,注意冲动性（12.39±2.27）,运动冲动性（18.51±3.40）,无计划冲动性（22.62±4.29）。SCL-90中除敌对因子外,均显著高于全国常模（P<0.01）;BIS-11量表的冲动性各因子分和总分分别与SCL-90各因子得分进行相关分析,结果显示除无计划冲动性因子与SCL-90中的强迫、人际关系、偏执、精神病性及其他因子无关外,其余均呈显著正相关。逐步多元回归分析结果显示,注意力冲动性（b=7.748,P=0.000）、运动冲动性（b=2.686, P=0.022）为心理健康的影响因素,并具有正性预测作用。结论：公交车驾驶员心理健康水平低于常人,高冲动性公交公司驾驶员的心理健康水平更低,应及时进行心理干预。     

Review of bus drivers' occupational stress and stress prevention

Although heterogeneous in methodology and content, 32 studies from 13 countries on bus drivers' work and health are similar in their conclusions. Bus-driving–characterized by high demands, low control and low support – can be regarded as a classic example of high-strain occupation, with high risks of physical and mental occupational ill-health, leading to absenteeism and to decreased productivity of employees and enterprises. Several recommendations – some of them already being implemented by bus companies – are presented in order to reduce work stress in bus drivers. They relate to: (a) ergonomics of the bus cabin, (b) job rotation and ‘combination jobs’, (c) timetables, shift schedules and quality of break periods, and (d) the social work environment and management style. Stress monitoring and stress reduction is not merely a technical process based on a technical analysis and on the simple ‘straightforward’ realization of recommendations and findings. It relates to changing and improving organizations and organizational processes. Such organization changes can best be obtained through a stepwise and participative approach. There are indications that those companies that invest in preventive measures receive their rewards.     

Benzene exposure in car mechanics and road tanker drivers

The purpose of this study was to identify professional factors related to benzene exposure and to deduce suitable safety measures. Atmospheric benzene, urinary muconic acid (tt-MA) and leukocyte alkaline phosphatase activity (LAPA) were evaluated among 66 car mechanics, 34 road tanker drivers, and 28 nonexposed workers. Professional and medical questionnaires were filled in at the same time. Atmospheric benzene was significantly higher among road tanker drivers than among car mechanics. The arithmetic mean ± SD, median, and geometric mean values were, respectively, 0.48 ± 1.49, 0.14, and 0.06 mg/m³ among car mechanics and 1.88 ± 4.18, 0.68, and 0.65 mg/m³ among road tanker drivers. In the latter case the increase was caused by transport of unleaded petrol and correlated with the volume of the tank. Among car mechanics, tobacco smoking, windy conditions, dismantling of petrol filters, and handling of petrol increased atmospheric benzene levels. Urinary muconic acid was increased significantly among car mechanics (148 ± 137, 127, and 111 μg/g) and among road tanker drivers (309 ± 420, 137, and 151 μg/g) as compared with the controls (49 ± 46, 33, and 33 μg/g). Among road tanker drivers, alcohol intake and transportation of unleaded petrol increased the excretion of muconic acid, which was also directly related to the volume of the tank. Among car mechanics, professional factors (dismantling of petrol filters, handling of and washing of hands with petrol) and nonprofessional factors (tobacco smoking and damaged skin on the hands and forearms) increased muconic acid excretion. In the control group, tobacco smoking increased its excretion. LAPA was not significantly modified among exposed workers. There was a weak but significant linear correlation between LAPA and muconic acid. These results suggest that to reduce exposure to benzene in unleaded petrol, individual and collective safety measures should be imposed in both occupations. Received: 25 November 1996 / Accepted: 25 September 1997     

Mental disorders and delivery motorcycle drivers (motoboys): A dangerous association

Objective

Low and middle-income countries experience an expressive growth in the number of circulating motorcycles, paralleled by an increasing number of traffic accidents. Delivery motorcycles drivers (“motoboys”) are generally perceived as accountable for this scenario. Although traffic accidents have a multivariate etiology, mental disorders, such as substance use disorders (SUD) and attention deficit/hyperactivity disorder (ADHD), are often involved. This paper aims at investigating the prevalence of ADHD, SUD and other mental disorders in a sample of Brazilian motoboys, and additionally, to evaluate the association between psychiatric diagnoses, motorcycle accidents and traffic violation tickets.

Method

A convenient sample of subjects was invited to participate in a cross-sectional assessment including an inventory of traffic accidents and violations. Psychiatric diagnoses were based on semi-structured and clinical interviews.

Results

A sample of 101 motoboys was assessed. Overall, 75% of subjects had a positive lifetime history of at least one psychiatric disorder. SUD was the most frequent diagnosis (43.6% for alcohol, 39.6% for cannabis). ADHD was associated with a higher number of traffic accidents (p = 0.002), and antisocial personality disorder (APD) was associated with a greater number of traffic violations (p = 0.007).

Conclusions

The prevalence of mental disorders was much higher in our sample than in the general population. ADHD and APD, but not SUD, were associated with negative traffic outcomes. These findings have implications for public mental health planning since mental disorders can be both prevented and treated, improving driving behavior and increasing road safety.     

Prevalence of drugs among drivers arrested for drinking and driving in Finland

Summary A combined thin layer and gas chromatography system was developed for qualitative and quantitative analysis of drugs in biological samples after extraction with heptane-isoamyl alcohol. Both acidic and basic extraction procedures were used. Special methods were used for the extraction and detection of salicylates, isoniazid, and morphine. Particular attention was given to the detection of psychostimulants; though these drugs have seldom been found in drinking drivers in Finland they are commonly found in Sweden. Two percent of all suspected drinking drivers were also suspected of concommitant drug use, which led to primary sampling of urine. Of 100 such drivers, 24 had blood alcohol levels (BALs) which were negative and 18 of that 24 had drugs in their sample. Seventysix of the 100 had positive BALs and 25 of the 76 had drugs in their samples. Of the randomly chosen 100 suspected drinking drivers, 5 had drugs in their samples, and 4 of these 5 had positive BALs. The benzodiazepines were the most commonly detected drugs. No stimulants were found in our subjects.The authors wish to thank Ms. Donna Billings for her skillful typing and checking the language. This study was supported by the Wihuri Foundation     

Less than 24 hour pseudo-periodicity in work schedules of train drivers,in relation to their sleep

Summary Relating back to research on sleep of French train drivers carried out by Foret and Lantin (1972), work schedules from a random sample of 180 successive on- and off-duty days of 4 train drivers were analysed. Work blocks cover 4 to 8 consecutive days, with off-duty times spent at home or away from home. Within these work blocks it appears that in 84 per cent of the cases, individual starting and finishing times of service fall earlier from one service to the following. On the whole they tend to sweep continuously the nycthemere counterclockwise, which results into less than 24 hours almost-periodicity of the work rest cycles. In 95 per cent of the work blocks, estimated periods are less than 24 hours, ranging in these cases from 19 hours to 23.60 hours (sample mean: 20.68 hours). Mean service duration observed in the sample is 7 hours. Mean effective driving task corresponds to 60 per cent of that time.The general hypothesis is made that such an artificial application of a work rest cycle which is less than 24 hours provides the least propitious conditions for development of so-called adaptive responses, at least as far as duration of sleep and intrasleep patterns are concerned, if subjects are at the same time submitted to circadian influences of environmental and socialZeitgeber.     

Raising Healthy Children: Examining the Impact of Promoting Healthy Driving Behavior within a Social Development Intervention

This study evaluated the impact of two targeted family sessions focused on driving issues delivered within the context of the Raising Healthy Children project. The Raising Healthy Children project began in the fall of 1993, drawing students in the 1st or 2nd grades from 10 schools. Schools were assigned to an intervention or control condition, and the school-wide, family- and student-focused preventive intervention to address developmentally salient risk and protective factors was delivered during elementary and middle school. The family driving sessions were administered to families in the intervention condition prior to and after teenagers received their driver's license. The first session consisted of a home visit with families designed to help parents and their children improve decision-making skills concerning driving and to develop clear standards and expectations regarding driving-related behavior. A second session, at the time of licensure, was designed to help parents and teens develop a written contract that stated family expectations, a plan for monitoring compliance with these expectations, and consequences for compliance or non-compliance.Consistent with the study's group-randomized design, intervention effects were assessed with multi-level logistic regression models in which students were grouped by their original school assignment. These models assessed specific effects of the driving sessions by adjusting for control variables measured when students were in 8th grade, prior to the driving sessions. Results indicated that students in the intervention group were more likely than students in the control group to report that they had a written driving contract (p = .003, OR = 4.98), and had participated in making the driving rules in the family (p = .025, OR = 1.70). Further, students in the intervention group reported significantly fewer risky behaviors including driving under the influence of alcohol (p = .021, OR = .45) and driving with someone who had been drinking (p = .038, OR = .56).