This study investigates possible acute effects on heart rate variability (HRV) when people are exposed to hand transmitted vibration and noise individually and simultaneously.
Ten male and 10 female subjects were recruited by advertisement. Subjects completed a questionnaire concerning their work environment, general health, medication, hearing, and physical activity level. The test started with the subject resting for 15 min while sitting down. After resting, they were exposed to one of four exposure conditions: (1) only vibration; (2) only noise; (3) both noise and vibration; or (4) a control condition of exposure to the static load only. All four exposures lasted 15 min and the resting time between the exposures was 30 min. A continuous electrocardiogram (ECG) signal was recorded and the following HRV parameters were calculated: total spectral power (P(TOT)); the spectral power of the very low frequency component (P(VLF)); the low frequency component (P(LF)); the high frequency component (P(HF)); and the ratio LF/HF.
Exposure to only vibration resulted in a lower P(TOT) compared to static load, whereas exposure to only noise resulted in a higher P(TOT). The mean values of P(TOT), P(VLF), P(LF), and P(HF) were lowest during exposure to vibration and simultaneous exposure to vibration and noise.
Exposure to vibration and/or noise acutely affects HRV compared to standing without these exposures. Being exposed to vibration only and being exposed to noise only seem to generate opposite effects. Compared to no exposure, P(TOT) was reduced during vibration exposure and increased during noise exposure.
To study whether work in a cold environment increased the risk of musculoskeletal symptoms in the neck and low back among construction workers.
This cross-sectional study is based on a cohort of male workers in the Swedish construction industry that participated in regular health examinations through a nationwide occupational health service. The analysis is based on workers examined from 1971 to 1974, who answered a questionnaire including questions about neck and back pain. The cohort consists of 134,754 male workers, including 16,496 office workers and foremen. The health examinations of the workers were conducted in provinces covering Sweden from the south to the north, and temperature data were collected for the provinces. In the analyses, the results were adjusted for age, BMI and use of nicotine.
The prevalence's of neck and low back pain were higher among manual construction workers than among foremen and office workers (24.3 vs. 8.6 % and 16.5 vs. 6.2 %, respectively); the corresponding adjusted ORs for low back and neck pain were 1.59 (95 % CI 1.52-1.66) and 1.39 (95 % CI 1.30-1.49), respectively. Workers in the northern and central provinces had higher ORs for low back and neck pain compared to workers in the southern province. The test for trends showed an increased risk of developing low back and neck pain with decreased outdoor temperature.
Outdoor work in a cold environment may increase the risk of low back and neck pain.
To identify factors associated with the reporting of cold sensitivity, by comparing cases to controls with regard to anthropometry, previous illnesses and injuries, as well as external exposures such as hand-arm vibration (HAV) and ambient cold.
Through a questionnaire responded to by the general population, ages 18-70, living in Northern Sweden (N?=?12,627), cold sensitivity cases (N?=?502) and matched controls (N?=?1004) were identified, and asked to respond to a second questionnaire focusing on different aspects of cold sensitivity as well as individual and external exposure factors suggested to be related to the condition. Conditional logistic regression analyses were performed to determine statistical significance.
In total, 997 out of 1506 study subjects answered the second questionnaire, yielding a response rate of 81.7%. In the multiple conditional logistic regression model, identified associated factors among cold sensitive cases were: frostbite affecting the hands (OR 10.3, 95% CI 5.5-19.3); rheumatic disease (OR 3.1, 95% CI 1.7-5.7); upper extremity nerve injury (OR 2.0, 95% CI 1.3-3.0); migraines (OR 2.4, 95% CI 1.3-4.3); and vascular disease (OR 1.9, 95% CI 1.2-2.9). A body mass index?=?25 was inversely related to reporting of cold sensitivity (0.4, 95% CI 0.3-0.6).
Cold sensitivity was associated with both individual and external exposure factors. Being overweight was associated with a lower occurrence of cold sensitivity; and among the acquired conditions, both cold injuries, rheumatic diseases, nerve injuries, migraines and vascular diseases were associated with the reporting of cold sensitivity.
To evaluate a method for collecting data concerning low back pain (LBP) using daily text messages and to characterize the reported LBP in terms of intensity, variability, and episodes.
We conducted a cohort study of LBP among workers used by a mining company. The participants were asked to answer the question "How much pain have you had in your lower back in the last 24 hours on a scale from 0 to 10, where 0 = no pain and 10 = the worst pain imaginable" once a day for 5 weeks, with this process being repeated 6 months later.
A total of 121 workers participated in the first period of data collection, and 108 participated in the second period. The daily response rate was 93% for both periods, and cluster analysis was shown to be a feasible statistical method for clustering LBP into subgroups of low, medium, and high pain. The daily text messages method also worked well for assessing the episodic nature of LBP.
We have demonstrated a method for repeatedly measuring of LBP using daily text messages. The data permitted clustering into subgroups and could be used to define episodes of LBP.
BACKGROUND, AIM, AND SCOPE: The main pathway for human exposure to the highly toxic polychlorinated-p-dioxins and polychlorinated furans [polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs)] is via dietary intake. Other exposure pathways may, however, be important in close proximity to point sources, such as wood preservation sites, where PCDD/F contaminated chlorophenols (CP) were previously used. In this study, a heavily PCDD/F contaminated CP saw mill site in Sweden was investigated. Human exposure through a broad spectrum of exposure pathways was assessed. Such studies are in demand since the question whether contaminated sites represent a current or future risk can only be answered by detailed site-specific risk assessments. MATERIALS AND METHODS: Sampling of exposure media (soil, air, groundwater, raspberries, carrots, potatoes, grass, milk, eggs, and chicken fodder) was made. Exposure media concentrations and congener distribution patterns were used to investigate the mobilization of PCDD/Fs from soil to the environment and to calculate exposure levels for adults. Blood serum levels from site-exposed and control individuals were also analyzed. RESULTS: Congener distribution patterns at the site were generally dominated by a specific marker congener (1234678-HpCDF), which is highly abundant in the polluted soil. The dioxin toxic equivalents (TEQ) concentrations were notably elevated as compared to national reference samples for most exposure media, and the marker congener was a major contributor to increased TEQ levels. There were also indications of soil-to-air volatilization of tetra- and penta-CDD/Fs. People who participated in the restoration of a contaminated building showed higher levels of 1234678-HpCDF compared to controls, and calculated exposure levels suggest that several site-specific exposure routes may be of importance for the daily intake of PCDD/F. CONCLUSIONS, RECOMMENDATIONS, AND PERSPECTIVES: Despite low mobility of higher chlorinated PCDD/Fs, these contaminants were transferred from the polluted soil to the surroundings and into human tissue. The extent of increased exposure from contaminated sites depends on the PCDD/F source strength of the soil, composition of the pollution, human activities, and dietary patterns of the residents. Impact from the contaminated soil on other exposure media was seen also for areas with low to moderate soil contamination. In the future, not only the levels of PCDD/F soil pollution but also the composition must be considered in risk assessments of contaminated sites.
Immediate and delayed outcomes after electrical injury. A guide for clinicians In Sweden about 300 electrical injuries are recorded each year at the Swedish National Electrical Safety Board. Most of our knowledge of the health consequences of these arise from clinical case series. Severe electrical injuries have direct thermal effects and may result in ventricular fibrillation, skin burns, as well as muscular and nerve affection. Long-term consequences include pain, vascular symptoms, cognitive and neurological symptoms and signs. These sequelae may occur even though the initial symptoms were relatively modest. Mechanisms are better understood for the immediate symptoms, compared to long-term and delayed non-thermal medical consequences. Attention to and treatment of patients with electrical injury needs to be improved to minimize long-term consequences. Good medical care in the acute phase and early multidisciplinary follow-up of severe cases will likely reduce associated morbidity. Each electrical injury should result in an inquiry to identify the cause of the accident in order to suggest actions to prevent new incidents.
Occupational exposure to irritants is associated with chronic bronchitis. The aim of this study was to elucidate whether repeated peak exposures with respiratory symptoms, gassings, to sulphur dioxide (SO2) and other irritant gases could increase the risk of chronic bronchitis.
The study population comprised 3,060 Swedish pulp mill workers (84% males) from a cohort study, who completed a comprehensive questionnaire with items on chronic bronchitis symptoms, smoking habit, occupational history, and specific exposures, including gassings. 2,037 have worked in sulphite mills. Incidence rates and hazard ratios (HRs) for the observation period, 1970-2000, in relation to exposure and the frequency of repeated gassings to SO2 and other irritant gases were calculated.
The incidence rate for chronic bronchitis among workers with repeated gassings was 3.5/1,000 person-years compared with 1.5/1,000 person-years among unexposed workers (HR 2.1, 95% confidence interval (CI) 1.4-3.1). The risk was even higher in the subgroup with frequent gassings (HR 3.2, 95% CI 2.0-5.2), particularly among never-smokers (HR 8.7, 95% CI 3.5-22).
Repeated gassings to irritant gases increased the incidence of chronic bronchitis in our study population during and after work in pulp mills, supporting the hypothesis that occupational exposures to irritants negatively affect the airways. These results underscore the importance of preventive actions in this work environment.
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Shift work is associated with increased risk of cardiovascular disease, but the causes have not yet been fully established. It has been proposed that the coronary risk factors are more hazardous for shift workers, resulting in a potential interaction effect with shift work.
To analyse interaction effects of work schedule and established risk factors for coronary artery disease on the risk of myocardial infarction.
This analysis was conducted in SHEEP/VHEEP, a case-control study conducted in two counties in Sweden, comprising all first-time cases of myocardial infarction among men and women 45-70 years of age with controls stratified by sex, age, and hospital catchment area, totalling to 4648 participants. Synergy index (SI) was used as the main outcome analysis method for interaction analysis.
There was an interaction effect between shift work and physical inactivity on the risk of myocardial infarction with SI of 2.05 (95% CI 1.07 to 3.92) for male shift workers. For female shift workers, interaction effects were found with high waist-hip ratio (SI 4.0, 95% CI 1.12 to 14.28) and elevated triglycerides (SI 5.69, 95% CI 1.67 to 19.38).
Shift work and some established coronary risk factors have significant interactions.
OBJECTIVES: The aim of this study was to analyze the relationship of job strain (high psychological job demands and low decision latitude) to hypertension, serum lipids, and plasmafibrinogen. METHODS: The study population consisted of employed persons between the ages of 15 and 64 years in the counties of Stockholm, V?sternorrland, and J?mtland, Sweden. The data collection was carried out during 1992-1998. A total of 10,382 subjects participated in a medical examination and completed a questionnaire. RESULTS: No strong associations were found between job strain and plasma fibrinogen. The males reporting job strain had lower levels of total cholesterol and high-density lipoprotein cholesterol than the other males. Similar tendencies were found for the females. The females, but not the males, with job strain had an increased prevalence of hypertension when compared with the subjects with relaxed psychosocial work characteristics. In the subgroups of younger males and females an adverse association between job strain and the ratio between low-density and high-density lipoprotein cholesterol was noted. CONCLUSIONS: The results do not support the hypothesis that job strain has an adverse impact on serum total cholesterol and plasma fibrinogen levels. They suggest that an increased risk of coronary heart disease in association with job strain, if causal, is mediated by other factors, possibly partly by hypertension and low levels of high-density lipoprotein cholesterol.
This cross-sectional questionnaire study was carried out at 4 open-pit mines in Finland, Norway, Russia and Sweden as part of the MineHealth project. The aim has been to compare the prevalence of musculoskeletal symptoms between drivers of mining vehicles and non-drivers.
The mine workers were asked whether they had suffered from any musculoskeletal symptoms during the previous 12 months in specified body regions, and to grade the severity of these symptoms during the past month. They were also asked about their daily driving of mining vehicles.
The questionnaire was completed by 1323 workers (757 vehicle drivers) and the reported prevalence and severity of symptoms were highest for the lower back, followed by pain in the neck, shoulder and upper back. Drivers in the Nordic mines reported fewer symptoms than non-drivers, while for Russian mine workers the results were the opposite of that. The daily driving of mining vehicles had no significant association with the risk of symptoms. Female drivers indicated a higher prevalence of symptoms as compared to male drivers.
The study provided only weak support for the hypothesis that drivers of vehicles reported a higher prevalence of musculoskeletal symptoms than non-vehicle drivers. There were marked differences in the prevalence of symptoms among workers in various enterprises, even though the nature of the job tasks was similar. Int J Occup Med Environ Health 2017;30(4):553-564.