1,721,001 research outputs found
Assessment of occupational risk in workers in the extractive sector due to exposure to whole body vibrations: a case study on the influence of the anthropometric characteristics on the measured vibration dose
No full textThe aim of this study is to investigate the possible correlation between the value of occupational risk from whole body vibrations and the main anthropometric characteristics of the subjects exposed to such vibrations. Directive 2002/44/EC, which defines the minimum requirements in order to guarantee the health and safety of workers exposed to such a risk, states that Risk Assessment may be conducted without resorting to taking any measurements on site, rather by simply referring to general information either from a database or that provided by the manufacturer of the machinery.The general parameters regarding the real exposure, such as for example the model of the machinery, the operating conditions and the duration of exposure, the nature of the terrain and the driving style in the case of vehicles or moving machinery, as well as the characteristics of the workplace must be declared in the final evaluation report (Standard EN 14253:2003). However, none of these parameters are directly connected to the final value of the risk assessment, nor are the worker's inertial or anthropometric parameters taken into account.The study is conducted through an analysis of a representative sample of workers who are exposed to a signal generated by various heavy site vehicles typically used in the extractive sector. The research attempts to highlight the way in which exposure to a Whole Body Vibration (WBV) vibratory signal depends heavily on the inertial characteristics of the person exposed and even more so on his or her anthropometric parameters. Of the latter the height and weight of the individual certainly appear to be the most important parameters.Lastly a possible general law of correlation between the input signal and the physical characteristics of the person exposed to vibrations, with a view to predict a statistical dependence of anthropometric parameters with the risk value to be assessed
A novel fault tree analysis approach to investigate uncommon accidents in quarries: A case study
No full textQuarrying companies are increasingly involved in developing effective Occupational Health and Safety Management Systems (OHSMS) to protect both their own staff and all those collaborating with their organization. The adoption of schemes such as BS OHSAS 18001:2007 helps the company to comply with legal requirements and serves the personnel both by raising awareness of the potential adverse consequences to which they are exposed (i.e., the risk of accident and potential occupational illness), and by limiting and managing the risk of occupational hazards. Since the quarry environment presents many hazardous factors, various approaches to monitor and control their effects are required; among them the choice of OHS risk assessment methods and the approach to accident investigation being the most crucial. This paper refers to a case study of an unusual accident which occurred in an Italian quarry recently. The analysis aims to identify and describe the true course of events, as well as to analyse the direct causes and contributing factors of the accident, the main objective being to identify best practices in risk reducing measures in order to prevent similar accidents occurring in the future. Initially a deductive approach is taken using the Fault Tree Analysis (FTA) method. This is then improved by integrating a Management Oversight and Risk Tree (MORT) technique and Multiple Cause Systems Oriented Incident Investigation (MCSOII). The proposed analysis is finally utilized to design and define procedures to manage these particular activities
Analysis of ground-transducer coupling in monitoring vibration from railways: A case study
No full textMonitoring railway-induced ground vibrations represents a fundamental step in assessing the environmental impact of train passage on buildings and surrounding receptors. For this purpose, accurate measurements of seismic waves are often required. Nevertheless, depending on soil structure, its characteristics or surface, the placement of transducer may affect the shape and phase of the seismic wave determining signal distortion and finally affecting the measurement itself. In particular, the most critical aspect of the sampling phase is represented by the coupling between the seismic transducer and the soil. Slipping or friction of the transducer may generate unacceptable results. For this purpose, different methods of coupling were tested in different conditions with regard to high speed train passages near a location in Rome. To start the test, some steel spikes of different shapes and lengths were tested in order to investigate their response to ground characteristics, surface and resonance frequency. The sampling campaign was carried out by fastening the transducers on the spikes fixed vertically in the soil at a certain distance from the railway track. Sampled data consisting of each passage in Peak Particle Velocity and acceleration were compared with those obtained by coupling transducers as defined in UNI 9916 norms. According to this norm, sensors are buried into the soil at a fixed depth depending on their dimensions. The final part of the sampling is aimed at comparing the sets of obtained values. This analysis is focused on the identification of those parameters to be taken into account in order to select the best coupling method for different conditions
Effectiveness of Antivibration Gloves When Used with a Light Electric Hammer. Differences Among Different Methods of Measurements
No full textSequential Gaussian Simulation as a tool to improve PM10 sampling scheme in industrial sites
No full textThis paper is focused on the role of spatial and variographic analysis in the phase of sampling design. In particular, when dealing with environmental variables such as airborne dust concentration all over a selected domain, the best approach to catch the spatial structure of the variable itself, implies the full and more detailed coverage of the domain. In this study this goal is achieved by means of about fifty airborne dust concentration field surveys all over a square area 350 mt wide in a quarry plant in the center of Italy. These data, sampled according with a regular pattern, did not allow to catch the spatial structure of the variable itself thus avoiding a satisfactory variographic modelling. To improve the sampling scheme an infilling procedure was performed by adding an increased number of samples. The selection of these further samples, less than 10% of the total amount, was carried out using sequential Gaussian simulations in those zones of the domain in which the highest variability was recorded. The final outcome shown a good result determining a good upgrade in terms of variographic modelling and final estimation at the cost of few further samples
Mechanical vibration and noise exposure on board of aircrafts
No full textMeasurements and risk assessment for mechanical vibration and noise are regulated by EU Directives 2002/44/CE and 2003/10/CE. In vibration databases we found vibration values data about several vibrating tools and some kind of ground vehicle, but there is a lack of data in the field of the air transport industry. Strictly related with vibration is noise: they have the same physical and mechanical nature and, remarkable by the point of view of the evaluation of the risks on health and safety of workers exposed, one of their synergic effects seems to be an increased Hearing Temporary Threshold Shift (T.T.S.), compared to T.T.S. due to noise only. Our work is the starting point to an accurate measurements to promote a risk analysis campaign particularly aimed at the air transport business.
Following the instruction set down by ISO Standards 2631-1 and UNI 9432 (2002) we measured mechanical vibrations and noise the pilots of two helicopters (EUROCOPTER EC 135 and AGUSTA BELL AB 412) and one airplane (BOMBARDIER CANADAIR CL 415) were exposed to during regular service and training missions. Noise has been measured both directly in the headsets, with internal and external communications included, and in the cabin without protection. In the worst case (helicopter AB 412) vibration values were under ‘action’ values until 150 minutes of daily exposure. Noise was found to be under action value up to 130 minutes of daily exposure in the EC 135, while in the AB 412 and CL 415 was over the action values for less than an hour exposure. Noise generated only by communications in the headsets, especially those external, should be noted
Operatori addetti alla ristorazione a bordo treno: studio della esposizione a vibrazioni e rumore
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