Epidemiology of occupational accidents among Iranian insured workers

Work-related accidents are considered as a major health problem worldwide. The aim of present study was to determine the epidemiological pattern of occupational accidents among workers insured by the Iranian Social Security Organization (ISSO) between 2001 and 2005.Subjects consisted of all workers and drivers who had a work-related accident during 2001–2005 and were registered in the Iranian Social Security Organization (ISSO) database according to the inspection reports. An ordinal logistic regression model (proportional odds regression model) was used to assess the concurrent effects of independent variables on accident outcomes.Overall, 86,437 work-related accidents were investigated. The accidents were more frequent in metal workplaces and electrical industries, respectively. More than half of the accidents were due to incautious activities. Workers’ age (age at the time of accident) (OR = 0.99, CI: 0.989–0.994), gender (OR = 1.3, CI: 1.191–1.683), marital status (OR = 1.25, CI: 1.143–1.675) as well as accident setting (OR = 1.88, CI: 1.728–1.975) had significant effect on accident outcomes. Pattern of occupational injuries in Iran was consistent with the global pattern for accident outcomes.     

The correlation between gradients of descending roads and accident rates

The traffic accident rate on descending roads on mountainous highways is quite high. To study the effects of vertical gradient and length of road on traffic accidents on continuous descending roads, data from 1413 traffic accidents over an 85.43 km section of road were collected. By taking parameters such as the gradients in accident sites, and taking the average gradient in N km (N = 1, 2, 3, 4, 5) just prior to the accident sites as the profile parameter, scatter diagrams were drawn to explore the effects of the profile parameters on the distribution of traffic accidents. Analysis of the exponential regression and correlation analysis between accident rates and profile parameters was carried out as well. The research results show that the accident rate increases with average vertical gradient exponentially; the differences between accident rate and different profile parameters are significant; the accident rate has a good exponential relationship with average gradients when a section has a 2 km or 3 km slope just prior to the accident sites i.e. the accident rate at a specific section on a continuous descending road is related to the average gradient in 2–3 km descending sections just prior to the accident site. The findings indicate that a steep gradient alone is not the reason for an accident, but we also have to take into consideration the presence of a “continuous long” descent prior to it.     

Educational status and organizational safety climate: Does educational attainment influence workers’ perceptions of workplace safety?

From a practical perspective, understanding the impact of education on perceptions of workplace safety would benefit management’s decisions regarding workers’ adaptability, general work effectiveness, accident frequency, implementation of safety management policies, and handling of education-related accident characteristics. The current study thus examined the relationship between educational attainment and (i) safety perception, (ii) job satisfaction, (iii) compliance with safety management policies, and (iv) accident frequency. Participants were Ghanaian industrial workers (N = 320) categorized into four educational groups based on their responses: basic education 50% (n = 159); secondary education, n = 98 (30%); vocational/professional education, 17% (n = 56); and university education, 3% (n = 7). Workplace safety perception was assessed with Hayes et al.’s 50-item Work Safety Scale (WSS): a scale that effectively captures the dimensions identified by safety experts to influence perceptions of workplace safety. Multivariate analysis (MANOVA) was used to test for differences of statistical significance. Posterior comparison with t-test consistently revealed significant differences between the two higher-educated cohorts and their lower-educated counterparts. The results indicated a positive association between education and safety perception. Higher-educated workers recorded the best perceptions on safety, indicated the highest level of job satisfaction, were the most compliant with safety procedures and recorded the lowest accident involvement rate.     

The self-defensive attribution hypothesis in the work environment: Co-workers’ perspectives

The study explored the possible influences of situational, personal and non-relevant perception on causality attributions and responsibility assignment in Ghana’s work environment. Ghanaian industrial workers (co-workers) who were witnesses to industrial accidents (n = 117) assigned causality for the mishap and their responses were compared. Analyses were based on the co-workers’ responses to open-ended questions. Three categories of co-workers were identified and labelled as situationally relevant (n = 34), personally relevant (n = 43) and non-relevant co-workers (n = 40). The results showed that co-workers (witnesses) who had some perception of situational and or personal relevance with the accident victims attributed less responsibility to the accident victims than did their counterparts who had no perception of relevance. This observation, like other motivated attributional distortions, seems to reflect a tendency towards self-protection from the three categories of co-workers. It confirms the self-defensive attribution hypothesis in causal attributions about accidents in the work environment.     

Study of the situation deduction of a domino accident caused by overpressure in LPG storage tank area

The production and storage of liquefied petroleum gas (LPG) is gradually becoming larger and more intensive, which greatly increases the risk of the domino effect of an explosion accident in a storage tank area while improving production and management efficiency. This paper describes the construction of the domino effect scene of an explosion accident in an LPG storage tank area, the analysis of the characteristics of the LPG tank explosion shock wave and the target storage tank failure, and the creation of an ANSYS numerical model to derive the development trend and expansion law of the domino accident in the LPG storage tank area. The research showed that: 400 m³ tank T1 explosion shock waves spread to T2, T4, T5, T3, and T6, and the tank overpressures of 303 kPa, 303 kPa, 172 kPa, 81 kPa, and 61 kPa respectively. The critical values of the target storage tank failure overpressure-range threshold were 70 kPa and 60 m. After the explosion of the initial unit T1 tank, at 38 ms, the T2 and T4 storage tanks failed and exploded; at 56 ms, the T5 storage tank exploded for the third time; at 82 ms, the T3 storage tank exploded for the fourth time; and at 102 ms, the T6 storage tank exploded for the fifth time. With the increase of explosion sources, the failure overpressure of the target storage tank increased, and the interval between explosions continuously shortened, which reflected the expansion effect of the domino accident. The domino accident situation deduction in the LPG storage tank area provided a scientific basis for the safety layout, accident prevention and control, emergency rescue, and management of a chemical industry park.     

Cultural and socio-demographic predictors of car accident involvement in Norway,Ghana, Tanzania and Uganda

The prevalence of road traffic accidents is increasing towards endemic proportions in developing countries. The present study investigated cultural and demographic predictors of car accident involvement in a developed country in Europe and three developing countries in Sub-Saharan Africa. The comparison was carried out with questionnaires among a randomly obtained representative sample of the Norwegian population (n = 247) as well as stratified samples in Accra and Cape-Coast in Ghana (n = 299), Dar-es-Salaam and Arusha areas in Tanzania (n = 599), and the central Kampala and the Mbarara district in Uganda (n = 415). Measurement instruments of culture as symbol exchange and destiny orientation were used to predict self-reported road traffic accident involvement by car among the respondents. Demographic characteristics, such as gender, age and education, were also included as predictors of car accidents. The results showed that male gender was the only significant predictor of accident involvement in Norway. Introverted and extroverted culture, destiny orientation and written culture were associated with accident involvement in the African countries. Male gender also predicted accidents in these countries. Non-technical injury preventive countermeasures in developing countries could focus on cultural practice and fatalistic beliefs. Countermeasures in both developed and developing countries should target male drivers.     

An explosion of a tank car carrying waste hydrogen peroxide

On the Metropolitan Expressway in Tokyo, a tank car exploded because it was carrying hydrogen peroxide (H₂O₂) in a compartment in which copper chloride (CuCl₂) remained. Although the main cause of the accident was trivial, the background on the accident suggested that an induction period in the reaction led to a mistake. This report describes the experimental investigation of the catalytic ability of CuCl₂, and comparing it with two other copper(II) compounds (nitrate: Cu(NO₃)₂; and copper sulfate: CuSO₄) and three iron(III) compounds (chloride: FeCl₃; nitrate: Fe(NO₃)₃; and sulfate: Fe₂(SO₄)₃).The experiments were performed using a reaction calorimeter. During the experiments at 35 °C, 2×10⁻⁵ mol of copper compounds slowly reacted with H₂O₂ and generated a precipitate. The iron compounds allowed the hydrogen peroxide to violently decompose. A 1×10⁻⁴ mol solution of CuCl₂, however, produced a violent decomposition at 35 °C. At 15 °C, a moderate heat release occurred.Based on these results, the concentration and temperature dependence of the catalytic ability of CuCl₂ were postulated to contribute to the induction period observed in the accident.     

Large N.G. explosion and fire involving several buried utility networks

This paper describes an accident (explosion and natural gas fire) that occurred in Turin (Italy), in which power distribution cables, tramway network feeding cables and a gas pipe were involved.The described accident is particularly interesting because it occurred in the town centre and lasted several hours, producing a very high risk for the population. Fortunately, nobody was injured, but 120 people were evacuated for 24 h. The sequence of events is described, the involved facilities are examined and the physical processes which led to the different top events are discussed. Actually, starting from a modest event (600 V electric cable loss of insulation), which most likely lasted for months, the aforementioned accident was reached in a crescendo of domino effects. This sequence has been represented by an ISD in which the failure of the different protection systems is highlighted. These protection systems were mostly based upon the strict respect of procedures both in the installation and in the following maintenance of the different utilities. These aspects have been also briefly devised in the light of Italian and foreign regulations concerning the problem of the coexistence of buried utilities.     

Risk assessment of safety and health (RASH) for building construction

In this research Risk Assessment of Safety and Health RASH method for building construction has been developed with risks classified into Safety Risks and Health Risks. 11 factors representing safety risks and 8 factors representing health risks were identified based on field survey in Oman. 40 Safety and Health specialists were involved in carrying out risk assessment using the existing method of risk analysis RA and the proposed RASH method. It was found that RASH method resulted in superior accuracy for assessment of risk zones than the existing RA method. The accuracy by RASH was almost twice the accuracy by RA. The overall percentages of the correct answers for the four scenarios using the RASH method and the RA method were 72.5 percent and 40 percent respectively. The proposed RASH method gave fewer errors than the existing RA method for all scenarios. Two scenarios were found to be the most problematic ones with largest overestimation of risks occur when using the existing RA method. Wilcoxon Ranked Test showed that the two methods are significantly different (z = −3.357, p > 0.01). The new method RASH is statistically acceptable and it resulted in better response in terms of estimating the risk than the RA method.     

Stochastic modeling of accident risks associated with an underground coal mine in Turkey

In this study, a methodology is proposed towards development of an uncertainty model that includes randomness in the occurrence of days-lost accidents in a coal mine. The accident/injury data consists of 1390 days-lost accident cases recorded at GLI-Tuncbilek underground lignite mine from January 1994 to December 2002. In the first step of proposed methodology, the frequency and the severity of the accidents have been modeled statistically by fitting appropriate distributions. The test done by BestFit software yields a chi-square value of 21.53 (p = 0.089) with 14 degrees of freedom and estimates the parameter of lambda for Poisson distribution as 12.87 accidents/month. For the severity component, a lognormal distribution is fitted to days-lost data and chi-square goodness-of-fit test calculates a value of 40.44 (p = 0.097) with 30 degrees of freedom. The parameters of lognormal distribution are estimated as a mean of 14.3 days and standard deviation of 23.1 days, respectively. Then, two distributions are basically combined by Monte Carlo simulation in order to construct relative risk levels in yearly base referring to the final cumulative distribution. Finally, a simple forecasting modeling is carried out in order to quantitatively predict the expected risk levels by using decomposition technique in time series analysis. Stochastic model estimates that although, there would be substantial reduction in the expected number of accidents in the near future, the higher level of risks still should be a concern for the mine management.     

Effects of lead time of verbal collision warning messages on driving behavior in connected vehicle settings

IntroductionUnder the connected vehicle environment, vehicles will be able to exchange traffic information with roadway infrastructure and other vehicles. With such information, collision warning systems (CWSs) will be able to warn drivers with potentially hazardous situations within or out of sight and reduce collision accidents. The lead time of warning messages is a crucial factor in determining the effectiveness of CWSs in the prevention of traffic accidents. Accordingly, it is necessary to understand the effects of lead time on driving behaviors and explore the optimal lead time in various collision scenarios.MethodsThe present driving simulator experiment studied the effects of controlled lead time at 16 levels (predetermined time headway from the subject vehicle to the collision location when the warning message broadcasted to a driver) on driving behaviors in various collision scenarios.ResultsMaximum effectiveness of warning messages was achieved when the controlled lead time was within the range of 5 s to 8 s. Specifically, the controlled lead time ranging from 4 s to 8 s led to the optimal safety benefit; and the controlled lead time ranging from 5 s to 8 s led to more gradual braking and shorter reaction time. Furthermore, a trapezoidal distribution of warning effectiveness was found by building a statistic model using curve estimation considering lead time, lifetime driving experience, and driving speed.ConclusionsThe results indicated that the controlled lead time significantly affected driver performance.Practical applicationsThe findings have implications for the design of collision warning systems.     

Driver speed selection and crash risk: Insights from the naturalistic driving study

IntroductionThis study investigates how speed limits affect driver speed selection, as well as the related crash risk, while controlling for various confounding factors such as traffic volumes and roadway geometry. Data from a naturalistic driving study are used to examine how driver speed selection varies among freeways with different posted speed limits, as well as how the likelihood of crash/near-crash events change with respect to mean speed and standard deviation.MethodRegression models are estimated to assess three measures of interest: the average speed of vehicles during the time preceding crash/near-crash and baseline (i.e., normal) driving events; the variation in travel speeds leading up to each event as quantified by the standard deviation in speeds over this period; and the probability of a specific event resulting in a crash/near-crash based on speed selection and other factors.ResultsSpeeds were relatively stable across levels-of-service A and B, within a range of 1.5 mph on average. Speeds were marginally lower (3.3 mph) on freeways posted at 65 mph versus 70 mph. In comparison, speeds were approximately 10.2 to 13.4 mph lower on facilities posted at 55 mph or 60 mph. Speeds were shown to be 2.5 mph lower in rainy weather and 11 mph lower under snow or sleet.ConclusionsSignificant correlation was observed with respect to speed selection behavior among the same individuals. Mean speeds are shown to increase with speed limits. However, these increases are less pronounced at higher speed limits. Drivers tend to reduce their travel speeds in presence of junctions and work zones, under adverse weather conditions, and particularly under heavy congestion. Crash risk increased with the standard deviation in speed, as well as on vertical curves and ramp junctions, and among the youngest and oldest age groups of drivers.     

Nursing student evaluation of NIOSH workplace violence prevention for nurses online course

Introduction: As primary targets of workplace violence in health care settings, nurses may suffer negative physical and psychological consequences. NIOSH created an online course to educate nurses about violence prevention techniques. Method: A mixed-methods approach assessed workplace violence awareness and knowledge among nursing students. A pre/post/post-test survey and focus group discussions evaluated participant awareness and knowledge, assessed course design, and solicited recommendations for increasing participation and strategies for improving message retention. Results: The mean awareness scores differed significantly between pre-course and both post-course time points (Wilk's λ = 0.319, F(2, 46) = 49.01, p < 0.001). Post hoc tests using the Bonferroni correction revealed that course participation increased awareness of workplace violence from pre-course scores (M = 0.75, SD = 0.438) to immediate post-course (M = 2.13, SD = 0.789) and four-week post-course (M = 1.96, SD = 0.771) scores on a 3-item measure. Similarly, mean knowledge scores increased between pre-course and both post-course time points (Wilk's λ = 0.495, F(1.57, 73.66) = 37.26, p < 0.001). Post hoc tests using the Bonferroni correction revealed that course participation increased knowledge of workplace violence from pre-course scores (M = 6.65, SD = 1.45) to immediate post-course (M = 8.56, SD = 1.32) and four-week post-course (M = 8.19, SD = 1.42) scores on a 10-item measure. Qualitative data from the focus groups reinforced the quantitative findings. Participants citing benefits from the content strongly recommended including the course in nursing curriculums. Incorporating the course early in the nursing educational experience will better prepare students to deal with workplace violence when they enter health care professions. Conclusions: The results indicate that NIOSH and its partners created an effective online workplace violence awareness and prevention course. Practical applications: Nursing students and professionals can be effectively educated about workplace violence using an online format.     

A study of pedestrian and bicyclist exposure to head injury in passenger car collisions based on accident data and simulations

The objective was to assess head injury risks and kinematics of adult pedestrians and bicyclists in primary impact to the passenger cars and secondary impact to the ground using real world accident data and computer reconstructions of the accidents. For this purpose, a subsample of 402 pedestrians and 940 bicyclists from the GIDAS database, Germany, was used for the statistical analysis, from which 22 pedestrian and 18 bicyclist accidents were further selected for reconstruction. PC-Crash was used to calculate impact conditions, such as vehicle impact velocity, vehicle kinematic sequence, and thrown distance. These conditions were employed to identify the initial conditions in reconstruction in MADYMO program. A comparable analysis was conducted based on the results from accident analysis and computer reconstructions for the impact configurations and the resulting injury patterns of pedestrians and bicyclists in view of head injury risks. Differences in HIC, head-relative impact velocity, linear acceleration, maximum angular velocity and acceleration, contact force, thrown distance, Wrap Around Distance (WAD), and head contact time were evaluated. Injury risk curves were generated by using a logistic regression model for vehicle impact velocity. The results indicate that bicyclists suffered less severe injuries compared with severity of pedestrian injuries. In the selected samples, the AIS 2+ and AIS 3+ head injury risks for pedestrians are 50% probability at impact speed of 38.87 km/h and 54.39 km/h respectively, while for bicyclists at 53.66 km/h and 58.89 km/h respectively. The findings of high injury risks suggested that in the area with high frequency car-pedestrian accidents, the vehicle speed limit should be 40 km/h, while in the area with high frequency car-cyclist accidents the vehicle speed limit should be 50 km/h.     

Investigation of affecting parameters on treating high-strength compost leachate in a hybrid EGSB and fixed-bed reactor followed by electrocoagulation–flotation process

In this research, treatability of high-load compost leachate in a hybrid expanded granular sludge bed (EGSB) and fixed-bed (FB) bioreactor followed by electrocoagulation–flotation (ECF) system was examined. The operational factors in EGSB–FB were influent chemical oxygen demand (COD), hydraulic retention time (HRT) and COD/nitrogen ratio (COD/N). And, their interactive effects on the efficiency of COD removal and biogas production rate (BPR) as responses were analyzed and correlated by response surface methodology (RSM). The optimum conditions of the hybrid EGSB–FB reactor were acquired at COD = 7800 mg/L, HRT = 35 h, COD/N = 70, in which COD removal efficiency was 83% and BPR 94 mL/h. The amount of confidence interval was 95%. COD (relevant coefficient = 9.8) and HRT (relevant coefficient = −24) were resulted respectively as the most effective parameters on COD removal and BPR. Yet, COD/N parameter imposed negative effect on COD removal and BPR in values less than about 100. The outcomes indicated that operated ECF as post-treatment in constant conditions (electrolysis time = 75 min, electrodes distance = 3 cm, voltage = 20 V) successfully satisfied discharge criteria in the most part of experimental domains.     

Preparation of iodine doped titanium dioxide to photodegrade aqueous bisphenol A under visible light

Highly photoactive iodine-doped titanium dioxide (I-doped TiO₂) photocatalysts were synthesized to degrade aqueous bisphenol A (BPA) under irradiation by visible light and sunlight. The band gap energies of TiO₂ and I-doped TiO₂ (I/Ti mole ratio = 0.5%) were 3.01 and 3.04, and the BPA photodegradation rate constants were 1.61, and 5.11 h⁻¹, respectively. The most probable reaction mechanism was proposed to involve IO₄⁻ and IO₃⁻ as electron acceptors that generate an inductive effect, increasing the photocatalytic efficiency of TiO₂. Results indicated that I-doped TiO₂ not only acted favorably as a photocatalyst, but also exhibited considerable mineralization effects. In addition, a recycling test after ten experiments demonstrated the stability and reusability of the photocatalyst.     

When bathing leads to drowning in older adults

Introduction: Bathing is the most problematic activity of daily living for aging adults, and the ability to perform it is influenced by physical capabilities that decrease with age. Drowning is an under-documented event related to bathing for older adults. This study investigates the circumstances of these tragedies, to prevent them. Methods: Census of 2005–2014 bathtub drownings in the province of Quebec (Canada) involving victims aged 65 +. Coroner's reports were analyzed using a grid based on factors previously associated with bath-related drownings in literature, iteratively modified. Results: Among the 92 bathtub drowning victims inventoried, 42% were aged 65 +. The average age of older victims is 79 (65–97, ± 9 years). Main probable cause of drowning is a cardiac problem, although only 19% of victims had a medical history of heart disease. Most victims were alone in their apartment or residence when drowning occurred. Risky periods appear to be springtime, Sundays, and evenings. Despite expectations, relevant information about the physical environment is very scarce. Conclusions: At least 39 Quebecers, aged 65 +, drowned in their bathtubs over a 10-year period. More older adults than children are victims of bathtub drownings in community-dwellings. It seems that bathing may induce heart distress, leading to an appreciable number of drownings. Practical implications: Since cardiac health problems are present in these deplorable events, promoting access to safety devices in the environment (emergency button, grab bars) and modified personal hygiene habits (bathing chair, showering) might be potential ways to prevent drowning and improve safety in older adults while they perform their personal hygiene, an essential activity for health and human dignity.     

Workers' compensation loss prevention representative contact and risk of lost-time injury in construction policyholders

IntroductionInsurance loss prevention (LP) representatives have access and contact with businesses and employees to provide targeted safety and health resources. Construction firms, especially those smaller in size, are a high-risk population. This research evaluated the association between LP rep contact and risk for lost-time injuries in construction policyholders.MethodsWorkers' compensation data were utilized to track LP rep contact with policyholders and incidence of lost-time injury over time. Survival analysis with repeated events modeling calculated hazard ratios (HR) and 95% confidence intervals (CI).ResultsCompared no LP contact, one contact was associated with a 27% reduction of risk (HR = 0.73, CI = 0.65–0.82), two with a 41% (HR = 0.59, CI = 0.51–0.68), and three or more contacts with a 28% reduction of risk (HR = 0.72, CI = 0.65–0.81).ConclusionsLP reps appear to be a valuable partner in efforts to reduce injury burden. Their presence or contact with policyholders is consistent with reduction in overall incidence of lost-time injuries.Practical applicationsReduction in lost-time injuries, resulting in reduced workers' compensation costs for policyholders and insurance companies, builds a business-case for safety and injury prevention. LP reps are often a low or no-cost benefit for insurance policyholders and may be an important injury prevention resource for small firms and/or those with lack of safety resources and staff.     

Ion exchange membrane-assisted electro-activation of aqueous solutions: Effect of the operating parameters on solutions properties and system electric resistance

The properties of electro-activated (EA) aqueous solutions as well as the dynamics of their changes were considered in the current study using aqueous solutions of NaCl and NaHCO₃. The concentrations of the salt solutions were 0.5, 0.25, 0.125 and 0.05 M. The tests were performed at the DC current densities of 25, 37.5, and 50 Å/m². The electro-activation reactor consisted of three individual cells assembled together and separated by anion-exchange (AEM) and cation-exchange (CEM) membranes. During the experiments, four configurations of the membrane placements and solutions concentrations were studied. The obtained results showed the dynamics of the electro-activation process that allows obtaining electro-activated solutions with targeted properties such as pH and oxydo-reduction potential (ORP). It was possible to obtain electro-activated solutions at the anodic side (acid anolyte) with pH of 3.0, 3.5, and 4.0 and ORP of +1100 ± 15 mV when NaCl solution was used as electrolyte. Furthermore, several types of electro-activated solutions with high redox potential (ORP = +921 ± 12 mV) and neutral pH (6.48 ± 0.05) were obtained on the anode side when sodium carbonate was used. At the same time, two types of solutions, one with acid pH (2.14 ± 0.14) and the other one with alkaline pH (10.46 ± 0.03) with ORP = +689 ± 10 and 110 ± 21 mV, respectively, were obtained in the central compartment which considered as electro-activated solutions obtained by means of noncontact electro-activation.