Effect of whole-body vibration exposures on physiological stresses: Mining heavy equipment applications

The aim of this study was to employ validated biological markers to quantify the physiologic consequences of exposure to whole-body vibration (WBV) and evaluate the relative impact of mining vehicle operator vibration exposure on physiological responses as compared to vertical-axial dominant WBV. In a laboratory-based study with a repeated-measures design, we played actual field-measured floor vibration profiles into a 6-degree-of-freedom motion platform to create different realistic WBV exposures: 1) vertical-dominant vibration collected from long-haul trucks, 2) multi-axial vibration collected from mining heavy equipment vehicles, and 3) no vibration (control condition). Circulating biomarkers of interest were cortisol and catecholamines (epinephrine and norepinephrine) to assess physiological stress, interleukin-6 (IL-6) and tumor necrosis factor-α (TNFα) to test for inflammation, thiobarbituric acid reactive substances (TBARS) to measure oxidative stress, and myoglobin and plasma creatine kinase to assess muscle damage. We collected blood samples at pre-exposure (0 h), during-exposure (2 and 4 h), and 2 h into recovery after the WBV exposure (6 h) in all four exposure conditions. The results showed that a single, 4-h acute exposure to WBV may not be sufficient to induce skeletal muscle damage, inflammation or physiologic stress measurable in the blood. No significant differences were observed between conditions for any of the biomarkers that could be attributed to the exposure contrast between vertical-dominant and multi-axial WBV exposures. These findings further indicate known complications of WBV exposure likely arise secondary to chronic, repeated exposures that give rise to subclinical stresses that were not captured here.

The effect of a multi-axis suspension on whole body vibration exposures and physical stress in the neck and low back in agricultural tractor applications

Whole body vibration (WBV) exposures are often predominant in the fore-aft (x) or lateral (y) axis among off-road agricultural vehicles. However, as the current industry standard seats are designed to reduce mainly vertical (z) axis WBV exposures, they may be less effective in reducing drivers' exposure to multi-axial WBV. Therefore, this laboratory-based study aimed to determine the differences between a single-axial (vertical) and multi-axial (vertical + lateral) suspension seat in reducing WBV exposures, head acceleration, self-reported discomfort, and muscle activity (electromyography) of the major muscle of the low back, neck and shoulders. The results showed that the multi-axial suspension seat had significantly lower WBV exposures compared to the single-axial suspension seats (p' < 0.04). Similarly, the multi-axial suspension seat had lower head acceleration and muscle activity of the neck, shoulder, and low back compared to the single-axial suspension seat; some but not all of the differences were statistically significant. These results indicate that the multi-axial suspension seat may reduce the lateral WBV exposures and associated muscular loading in the neck and low back in agricultural vehicle operators.

Detecting the environmental impact of off-road vehicles on Rawdat Al Shams in central Saudi Arabia by remote sensing

Off-road vehicles can have a devastating impact on vegetation and soil. Here, we sought to quantify, through a combination of field vegetation, bulk soil, and image analyses, the impact of off-road vehicles on the vegetation and soils of Rawdat Al Shams, which is located in central Saudi Arabia. Soil compaction density was measured in the field, and 27 soil samples were collected for bulk density analysis in the lab to quantify the impacts of off-road vehicles. High spatial resolution images, such as those obtained by the satellites GeoEye-1 and IKONOS-2, were used for surveying the damage to vegetation cover and soil compaction caused by these vehicles. Vegetation cover was mapped using the Normalized Difference Vegetation Index (NDVI) technique based on high-resolution images taken at different times of the year. Vehicle trails were derived from satellite data via visual analysis. All damaged areas were determined from high-resolution image data. In this study, we conducted quantitative analyses of vegetation cover change, the impacts of vehicle trails (hereafter "trail impacts"), and a bulk soil analysis. Image data showed that both vegetation cover and trail impacts increased from 2008 to 2015, with the average percentage of trail impacts nearly equal to that of the percentage of vegetation cover during this period. Forty-six species of plants were found to be present in the study area, consisting of all types of life forms, yet trees were represented by a single species, Acacia gerrardii. Herbs composed the largest share of plant life, with 29 species, followed by perennial herbs (12 species), grasses (5 species), and shrubs (3 species). Analysis of soil bulk density for Rawdat Al Shams showed that off-road driving greatly impacts soil density. Twenty-two plant species were observed on the trails, the majority of which were ephemerals. Notoceras bicorne was the most common, with a frequency rate of 93.33 %, an abundance value of 78.47 %, and a density of 0.1 in transect 1, followed by Plantago ovata.

Injuries related to off-road vehicles in Canada

Off-road vehicles (ORVs; this includes snowmobiles, all-terrain vehicles or ATVs and dirt bikes) were once used primarily for work and travel. Such use remains common in Canada, although their recreational use has also gained popularity in recent years. An epidemiological injury profile of ORV users is important for better understanding injuries and their risk factors to help inform injury prevention initiatives. The Traffic Injury Research Foundation (TIRF) partnered with the Public Health Agency of Canada (PHAC) to analyze the epidemiology of ORV-related injuries. The primary aim was to assess crashes and injuries in Canada, including the extent of alcohol involvement. Secondly, the burden of injury among children and teen ORV drivers in Canada, as well as passengers, was investigated. Descriptive and inferential epidemiological statistics were generated using the following data sources: first, TIRF's National Fatality Database, which is a comprehensive, pan-Canadian, set of core data on all fatal motor vehicle crashes; second, TIRF's Serious Injury Database, which contains information on persons seriously injured in crashes; and, third, PHAC's Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP), a surveillance system currently operating in the emergency departments of some pediatric and general hospitals across Canada. Exposure data have been used in the analyzes where available. Between 1990 and 2010, fatality rates increased among ATV and dirt bike operators. The fatality rate among snowmobilers declined during this period. Of particular concern, among fatally injured female ATV users, children aged 0-15 years comprised the highest proportion of any age group at 33.8%. Regarding alcohol use, among fatally injured snowmobile and ATV/dirt bike operators tested for alcohol, 66% and 55% tested positive, respectively. Alcohol involvement in adult ORV crashes remains an important factor. In light of the growing popularity of ORVs, prevention and mitigation measures are required to address this issue.