| 1. |
- Björ, Bodil, et al.
(författare)
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Acute effects on heart rate variability when exposed to hand transmitted vibration and noise.
- 2007
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Ingår i: International Archives of Occupational and Environmental Health. - : Springer Science and Business Media LLC. - 0340-0131 .- 1432-1246. ; 81:2, s. 193-199
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: This study investigates possible acute effects on heart rate variability (HRV) when people are exposed to hand transmitted vibration and noise individually and simultaneously. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
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| 2. |
- Björ, Bodil, et al.
(författare)
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Cold health impacts in northern Sweden
- 2016
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Ingår i: International Journal of Circumpolar Health. - : Informa UK Limited. - 1239-9736 .- 2242-3982. ; 75:33200
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Björ, Bodil, et al.
(författare)
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Fifty-year-follow-up of mortality among a cohort of iron-ore miners in Sweden, with specific reference to myocardial infarction mortality
- 2009
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Ingår i: Occupational and Environmental Medicine. - London : BMJ Publishing Group. - 1351-0711 .- 1470-7926. ; 66:4, s. 264-268
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: This study investigates both general mortality and mortality from myocardial infarction among men employed in iron-ore mines in Sweden.Methods: The mortality of employees (surface and underground workers) at the iron-ore mines in Malmberget and Kiruna, Sweden was investigated. The study cohort comprised men who had been employed for at least 1 year between 1923 and 1996. The causes of death were obtained from the national cause of death register from 1952 to 2001. Indirect standardised mortality ratios (SMR) were calculated for four main causes. Mortality specifically from myocardial infarction was also analysed.Results: 4504 deaths in the cohort gave an SMR for total mortality of 1.05 (95% CI 1.02 to 1.09). Mortality was significantly higher for lung cancer (SMR 1.73, 95% CI 1.52 to 1.97). There was an increased risk of injuries and poisonings (SMR 1.34, 95% CI 1.24 to 1.46) and respiratory diseases (SMR 1.14, 95% CI 1.00 to 1.28). There were 1477 cases of myocardial infarction, resulting in an SMR of 1.12 (95% CI 1.07 to 1.18). SMR was higher (1.35, 95% CI 1.22 to 1.50) for men aged ≤60 years than for those >60 years of age (1.06, 95% CI 1.00 to 1.13).Conclusions: Mortality from myocardial infarction was higher than expected. There was also an increased risk of death from injuries and poisonings, lung cancer and respiratory diseases, as well as higher general mortality. Our findings support the results of previous studies that there is an association between working in the mining industry and adverse health outcomes.
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| 4. |
- Björ, Bodil M, et al.
(författare)
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Mortality from myocardial infarction in relation to exposure to vibration and dust among a cohort of iron-ore miners in Sweden
- 2010
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Ingår i: Occupational and Environmental Medicine. - : BMJ Publishing Group. - 1351-0711 .- 1470-7926. ; 67:3, s. 154-158
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The aim of this study was to investigate myocardial infarction mortality in relation to exposure to hand-arm vibration (HAV) and whole-body vibration (WBW) as well as exposure to dust among men employed in two Swedish iron-ore mines. METHODS: This study comprised employed men at two iron-ore mines in Sweden who had been employed for at least one year from 1923 up to 1996. The causes of death were obtained from the national cause of death register from 1952 to 2001. Myocardial infarction mortality was obtained by linking personal identification numbers to the national cause of death register. Poisson regression was used for risk estimations on exposure-response relation, and analyses were made on the two age groups 60 years. RESULTS: Relative risks for myocardial infarction mortality in relation to exposure were significantly increased for exposure (0/>0) to WBV (RR: 1.18, 95% CI 1.06-1.31) and dust (RR: 1.15, 95% CI 1.02-1.31), and the results indicated an exposure-response relation for WBV and dust separately. For 60 years and younger, exposure to HAV (0/>0) (RR: 1.34, 95% CI 1.03-1.74) and WBV (0/>0) (RR: 1.39, 95% CI 1.13-1.72) increased the risk of MI mortality. An exposure-response was found for HAV and WBV, as the medium and high exposed categories showed significantly increased risk estimates. None of the exposures significantly increased the risk in the group above 60 years. The increased risk estimates for exposure to WBV remained when adjusting for exposure to dust. CONCLUSIONS: The results for the working-age (
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| 5. |
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| 6. |
- Björ, Ove, 1967-, et al.
(författare)
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Do physical workload or temperature characteristics in an outdoor workingenvironment explain deviating rates of mortality and incidental cancer? A cohort study based on iron-ore mining.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background A cohort study that examined iron ore mining found negative associations between cumulative working time employed underground and several severe outcomes. In this cohort study, and using the same group of miners, we examined whether heavy physical workload or the temperature characteristics represented by an outdoor working environment could explain these lower rates.Method This study was based on a Swedish iron ore mining cohort consisting of 13000 workers employed between 1923 and 1998. Exposure was defined as cumulative employment time in heavy physical workload or outdoor work. Poisson regression models were used to generate smoothed estimates of standardized morbidity ratios and adjusted rate ratios, both models by cumulative exposure time. SMRs for different cohort subgroups were used to compare the occurrence of cerebrovascular disease mortality to the reference population.Results The adjusted rate ratio between employment classified as outdoor work ≥25 years and short term outdoor work was 1.62 (95% CI 1.07–2.42). The subgroup underground work ≥15 years deviated most in occurrence of cerebrovascular disease mortality compared with the reference population: SMR (0.70 (95% CI 0.56–0.85)). No elevated rates were associated with cumulative employment time representing heavy physical workloads.Conclusion Employment in temperature shifting outdoor environments was associated with elevated rates of cerebrovascular disease mortality. In contrast, work in tempered underground employment was associated with a protecting effect. Based on selected groups of mortalities, physically heavy workloads did not protect for mortality later in life.
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| 7. |
- Björ, Ove, et al.
(författare)
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Is outdoor work associated with elevated rates of cerebrovascular disease mortality? : a cohort study based on iron-ore mining
- 2016
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Ingår i: Journal of Occupational Medicine and Toxicology. - : Springer Science and Business Media LLC. - 1745-6673. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A cohort study that examined iron ore mining found negative associations between cumulative working time employed underground and several outcomes, including mortality of cerebrovascular diseases. In this cohort study, and using the same group of miners, we examined whether work in an outdoor environment could explain elevated cerebrovascular disease rates.METHODS: This study was based on a Swedish iron ore mining cohort consisting of 13,000 workers. Poisson regression models were used to generate smoothed estimates of standardized mortality ratios and adjusted rate ratios, both models by cumulative exposure time in outdoor work.RESULTS: The adjusted rate ratio between employment classified as outdoor work ≥25 years and outdoor work 0-4 years was 1.62 (95 % CI 1.07-2.42). The subgroup underground work ≥15 years deviated most in occurrence of cerebrovascular disease mortality compared with the external reference population: SMR (0.70 (95 % CI 0.56-0.85)).CONCLUSIONS: Employment in outdoor environments was associated with elevated rates of cerebrovascular disease mortality. In contrast, work in tempered underground employment was associated with a protecting effect.
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| 8. |
- Burström, Lage, et al.
(författare)
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A follow-up study of welders’ exposure to vibration in a heavy engineering production workshop
- 2010
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Ingår i: Journal of Low Frequency Noise Vibration and Active Control. - : Sage Publications. - 0263-0923 .- 1461-3484 .- 2048-4046. ; 29:1, s. 33-39
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Tidskriftsartikel (refereegranskat)abstract
- Manual work involving vibrating power tools is associated with symptoms that include vascular, neurological and musculoskeletal disorders. This study examines the vibration exposure of welders to determine the change between 1987 and 2008. Vibration measurements on handheld tools were used to evaluate the acceleration and the daily exposure time was determined by subjective rating. From these data, the 8-hour equivalent vibration exposure A(8), has been calculated. During the period, the A(8) decreased from 3.9 m/s2 to 1.9 m/s2. It was concluded that this decrease is the result of fewer vibrating tools and a decrease in daily exposure time. Although the daily vibration exposure has decreased over the study time, for some welders the daily vibration exposure A(8) is still above the action value set by the EU directive on vibration. This means more effort should be spent to decrease vibration exposure.
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| 9. |
- Burström, Lage
(författare)
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Absorption of vibration energy in the human hand and arm
- 1990
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The risk assessment of hand-arm transmitted vibration is today based on measurements of the magnitude, frequency spectra and duration of the vibration stimuli. It is, however, reasonable to assume that the detrimental effects might depend on the vibration energy absorbed by the hand and arm. Therefore, the aims of this thesis have been to; (i) examine the mechanical and energy absorbing properties of the hand and arm during vibration exposure, (ii) perform theoretical calculations of the amount of absorbed energy, (iii) compare the calculated results with direct measurements. The results show that the mechanical and energy absorbing properties depend on the frequency and direction of the vibration stimuli. Higher vibration levels, as well as more firm handgrips, resulted in higher impedance and absorption of energy. The constitution of the hand and arm also affected, the results to a large extent whereas the varying hand-arm postures had only a small influence. Using the vibration characteristics for a certain tool and the mechanical properties of the hand and arm, a good agreement between theoretical calculations and direct measurements of the amount of absorbed energy could be established. Furthermore, the shape of the frequency spectra for the energy absorption was found to be unequal for different vibration directions and not in accordance with the currently used frequency weighting routine. Finally, the findings support the idea that future standards for risk assessment of vibrations should rather be based on the energy absorption concept.
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| 10. |
- Burström, Lage, et al.
(författare)
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Absorption of vibration energy in the human hand and arm
- 1994
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Ingår i: Ergonomics. - : Informa UK Limited. - 0014-0139 .- 1366-5847. ; 37:5, s. 879-890
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Tidskriftsartikel (refereegranskat)abstract
- A possible basis for the risk assessment for hand-transmitted vibration may be to determine the amount of energy absorbed in the human hand and arm. In the present study, the mechanical energy absorption in the hand-arm system was measured within the frequency range of 4 to 1000 Hz. The study was carried out on ten healthy subjects during exposure to sinusoidal vibration. The influence of various experimental conditions, such as vibration direction (Xh, Yh, Zh), grip force (25-75 N), vibration level (8-45 mm/srms), and hand-arm posture were studied. The outcome shows that the energy absorption in the human hand and arm depended mainly on the frequency and direction of the vibration stimulus. Higher vibration levels, as well as firmer handgrips, resulted in higher absorption of energy. Varying hand-arm postures had only a small influence on the amount of absorbed energy, while the constitution of the hand and arm affected the energy absorption to a larger extent.
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