In-vehicle noise exposure among military personnel depending on type of vehicle, riding compartment and road surface.

INTRODUCTION: Noise-induced hearing loss is one of the most common health problems among military service personnel. Exposure to noise in military vehicles constitutes a large proportion of total noise exposure. This pilot study aimed to evaluate in-vehicle noise levels depending on the type of vehicle, riding compartment and road surface. METHOD: Noise levels were measured in armoured personnel carriers and heavy all-terrain trucks, in the cab and rear passenger compartment, while driving on paved or off-road surfaces. The results were compared with national LLV and allowed noise exposure times were calculated per vehicle and surface. RESULTS: The equivalent noise levels in the cab of SISU XA-188 (p=0.001) and peak noise levels in MAN 4620 (p=0.0001) and DAF 4440 (p=0.0047) were higher on paved road, compared with off-road. The equivalent noise levels in the canvas covered rear compartment of MAN 4620 were significantly higher than in the cab on both paved (p=0.004) and off-road (p=0.0003). Peak noise levels in the cab of DAF 4440 exceeded the parameters measured in the canvas covered rear compartment on both paved (p=0.002) and off-road (p=0.0002). In most cases, peak noise levels were below the LLV (p=0.02-0.0001). The maximum noise exposure to passengers in the canvas covered rear compartment of MAN 4620 despite road surface was calculated 0.6 hours per working day. CONCLUSION: A high risk of noise-induced hearing loss among military personnel occurs during long distance transportation with vehicles showing noise levels higher than allowed LLV.

Drivers of international variation in prevalence of disabling low back pain: Findings from the Cultural and Psychosocial Influences on Disability study.

BACKGROUND: Wide international variation in the prevalence of disabling low back pain (LBP) among working populations is not explained by known risk factors. It would be useful to know whether the drivers of this variation are specific to the spine or factors that predispose to musculoskeletal pain more generally. METHODS: Baseline information about musculoskeletal pain and risk factors was elicited from 11 710 participants aged 20-59 years, who were sampled from 45 occupational groups in 18 countries. Wider propensity to pain was characterized by the number of anatomical sites outside the low back that had been painful in the 12 months before baseline ('pain propensity index'). After a mean interval of 14 months, 9055 participants (77.3%) provided follow-up data on disabling LBP in the past month. Baseline risk factors for disabling LBP at follow-up were assessed by random intercept Poisson regression. RESULTS: After allowance for other known and suspected risk factors, pain propensity showed the strongest association with disabling LBP (prevalence rate ratios up to 2.6, 95% CI: 2.2-3.1; population attributable fraction 39.8%). Across the 45 occupational groups, the prevalence of disabling LBP varied sevenfold (much more than within-country differences between nurses and office workers), and correlated with mean pain propensity index (r = 0.58). CONCLUSIONS: Within our study, major international variation in the prevalence of disabling LBP appeared to be driven largely by factors predisposing to musculoskeletal pain at multiple anatomical sites rather than by risk factors specific to the spine. SIGNIFICANCE: Our findings indicate that differences in general propensity to musculoskeletal pain are a major driver of large international variation in the prevalence of disabling low back pain among people of working age.

Changes of sympatho-adrenal and hypothalamo-pituitary-adrenocortical system in patients with head injury.

To determine the role of the sympatho-adrenal (SAS) and hypothalamo-pituitary-adrenocortical system (HPAS) after head injury, the relationship between venous blood epinephrine (E), norepinephrine (NE), adrenocorticotropic hormone (ACTH), cortisol levels, and clinical condition was examined in 55 patients. These observations suggest that head injury causes mainly activation of the above-mentioned systems depending on the severity of trauma. An inverse correlation between the levels of E, NE and Glasgow Coma Scale score, indicating the severity of head injury was revealed. ACTH and cortisol were similarly related to the clinical condition, although the observed correlation was less expressed. The changes in hormonal levels were present during the whole research period (1 week), although a certain shift to normalization was observed. However, catecholamines and ACTH levels in plasma were relatively low in severely head-injured patients whose CT scans revealed serious alterations in the mesencephalic-diencephalic area. At the same time their cortisol levels obtained maximal values and their chance to survive was diminutive. The results of this study indicate that investigation of hormones of SAS and HPAS might be useful as an additional method in the complex of ordinary examinations in establishing early prognosis in patients with brain injury.

[The dependence of the function of the sympathetic-adrenal and hypothalamo-hypophyseal-adrenal cortical systems on the severity of the traumatic brain lesion]. / Zavisimost' sostoianiia simpatiko-adrenalovoi i gipotalamo-gipofizarno-adrenokortikal'noi sistem ot tiazhesti travmaticheskogo porazheniaia golovnogo mozga.

A total of 43 males with craniocerebral injury of varying severity were studied for the venous blood plasma levels of adrenaline, noradrenaline, adrenocorticotrophic hormone, and hydrocortisone in dynamics. Their computed tomograms were quantitatively analysed to identify the site of contusion foci in the cerebral hemispheres, especially the lesion signs of mesodiencephalic and truncal regions of the brain. The results of the studies and non-linear regression analysis have shown that brain injury leads to a substantial activation of the body's sympathoadrenal system, extremely severe injury causes its partial reduced performance. In severe and critical cerebrocranial injury, the central link of the hypothalamus-pituitary-adrenocortical system is exhausted and hydrocortisone release occurs without its control. The above changes depend on the size of hepatoma and edema of the cerebral hemispheres and on secondary lesion of the brain mesodiencephalic and truncal regions. The activity of the sympathoadrenal and hypothalamus-pituitary-adrenocortical system, which was observed over a week, tended to its gradual decrease.