Injury estimation risk assessment

Risk iuialysis of accidents serves a dual purpose. It estimates tlie probability tliat iui accident will occur and also assesses the severity of the consequences of an accident. Consequences may include dmnage to tlie surrounding enviromnent, financial loss, injury to life and/or deatli. This Part of the book (Part IV) is primarily concerned witli tlie metliods used to identify liazards and causes and consequences of accidents. Issues dealing witli healtli risks have been explored in die previous Part (III). Risk assessment of accidents provides an effective way to help ensure eidier diat a mishap will not occur or reduces the likelihood of an accident. The result of die risk assessment also allows concerned parties to take precautions to prevent an accident before it happens. 

The reader should note tliat since many risk assessments have been conducted on the basis of fatal effects, there are also uncertainties on precisely what constitutes a fatal dose of thennal radiation, blast effect, or a toxic chemical. Where it is desired to estimate injuries as well as fatalities, tlie consequence calculation can be repeated using lower intensities of exposure leading to injury rather titan dcatli. In addition, if the adverse healtli effect (e.g. associated with a chemical release) is delayed, the cause may not be obvious. Tliis applies to both chronic and acute emissions and exposures. 

If one conducts a literature search on the term risk assessment, a lengthy list of publications on a range of topics will be produced (NAS/NRC, 1983 1994 Paustenbach, 1995), because this term has been used to describe estimates of the likelihood of a number of unwanted events. These include, for example, industrial explosions, workplace injuries, failures of machine parts, natural catastrophes, injury or death as a result of voluntary activities or lifestyle, diseases, and death from natural causes. 

The process of risk assessment can be defined as t/ie evaluation and quantification of the likelihood of undesired events and the likelihood of injury and damage that could be caused by the risks. It also involves an estimation of the results resulting from undesired events. 

Modeling health effects from various hazard levels is a difficult task. Risk assessments are typically based on the risk of death or serious injury. Obviously there are no experimental data available on the dose-response relationship of material concentration and exposure duration, thermal radiation intensity or blast overpressures on humans. What little there is has been inferred from actual accidents. Models that predict the impact of exposure to hazardous materials are heavily influenced by animal experiments. Typically, they have large safety factors built in. It is believed that models based primarily on exposure of experimental animals are conservative when applied to humans, especially when, on a body weight difference, the animals are much smaller than humans. In fact, many will argue that they are too conservative. These estimates are difficult to make, and unfortunately little can be done to improve the degree of uncertainty. 

A number of attempts to a more systematic and consistent approach to quantitative occupational risk assessment have appeared in the hterature. A model has been developed to predict the frequency of occupational accidents in offshore oil and gas industry, based on direct, corporate and external factors, as proposed by Attwood et al. (2006). Quantified risk for various occupational groups in Sweden based on the number of accidents and relevant exposure has been calculated by Larsson and Forsblom (2005). A method has been proposed by Ivan et al. (2010) for risk assessment of several trades in the construction industry, based on estimating the overall frequency and severity from historical data of accidents in Hong Kong and their consequences regarding injuries, days lost and compensation cost. Fuzzy methods have been... 

Risk assessment A comprehensive estimation of the probability and the degree of possible injury or damage in a hazardous situation, made in order to select appropriate safety measures. 

Potential health and economic consequences of nuclear power plant accidents include early fatalities, early injuries, latent cancers, population doses, various health effects, and onsite and offsite costs. For such consequence measures, application of the preceding deftnition of risk becomes more complicated, because frequencies must be estimated for accidents with varying degrees of severity. For example, the frequency of transportation accidents involving 100 or more early fatalities is substantially lower than the frequency of transportation accidents involving only 1 fatality. In risk assessments, frequencies of accidents with all possible consequence levels are estimated. It is desirable to combine the risks associated with high, moderate, and low consequence accidents into an overall risk measure. For this purpose, the concept of actuarial or consequence-weighted risk is used. 

After the hazard assessment has been conducted and the data has been collected, it should be organized in a logical outline that will estimate the potential for employee injury The organized data will help to decide the type of hazard(s) involved, the level of risk, and the seriousness of potential injury The appropriate levels of PPE are then selected based on the hazard determination and the availability of PPE. The user should be properly fitted for the specified PPE, and the employer should make sure that it is comfortable to wear. Hazard reassessments should be conducted as necessary based on the introduction of new or revised processes, equipment, and accident experience, to ensure the continued suitability of selection of the proper PPE. 

Therefore, the estimation of a medical device s safety lies the determination of the probability that a medical device would become hazardous for the user or patient, resulting in safety problems and harm. This activity is known as risk management and is regulated by International Organization for Standardization (ISO) standard 14,971 [63,64]. This process is divided in two activities, risk analysis and risk evaluation, that assist in a detailed assessment of the risks associated to the medical device s entire life cycle, from manufacturing to disposal. The estimation of the risk is a complex procedure that considers the probability of device failure or nonconformity, software, user errors, and type of injury possibly resulting to people or users. 

Deciding the likelihood of a hazard causing injury or damage is difficult. Whatever system is chosen it should be remembered that human beings do make errors, whether they be risk estimators or those at risk, so any probability assessment carries with it a degree of uncertainty. 

Evaluation of the risk requires an estimation of the likely severity of any injury or damage and of the probability of it happening. A procedure for obtaining information needed to make the assessment of the risk is outlined in EN 1050 . ... 

It has been estimated that at least a quarter of all fatal injuries at work involve failures in systems of work — the way things get done. A safe system of work is a formal procedure that results from a systematic examination of a task in order to identify all the hazards and assess the risks, and which identifies safe methods of work to ensure that the hazards are eliminated or the remaining risks are minimised. Where elements of risk remain, a safe system of work will be required. Some examples where safe systems of work will be part of the controls are ... 

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