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.     

Flammability of hydrocarbon and carbon dioxide mixtures

The effect of carbon dioxide (CO₂) concentration on the ignition behaviour of hydrocarbon and CO₂ gas mixtures is examined in both jets and confined explosions. Results from explosion tests are presented using a 20 l explosion sphere and an 8 m long section of 1.04 m diameter pipeline. Experiments to assess the flame stability and ignition probability in free-jets are reported for a range of different release velocities. An empirically-based flammability factor model for free-jets is also presented and results are compared to ignition probability measurements previously reported in the literature and those resulting from the present tests.The results help to understand how CO₂ changes the severity of fires and explosions resulting from hydrocarbon releases. They also demonstrate that it is possible to ignite gas mixtures when the mean concentration is outside the flammable range. This information may be useful for risk assessments of offshore platforms involved in carbon sequestration or enhanced oil recovery, or in assessing the hazards posed by poorly-inerted hydrocarbon processing plant.     

Safety compliance climate concerning risk assessment and preventive measures in EU legislation: A Finnish survey

The aim of the present study is to explore the process dynamics of the safety compliance climate and work relationships, including their antecedents and consequences. After investigating the many dimensions of safety compliance climate and of work relationships, the study concludes that a multi-component measure is needed to fully assess all of their dimensions. With respect to the impacting positively on safety compliance legislation, the present study found the following factors: “contribution measures”, “concrete preventive measures” and “risk assessment process”. For risk assessment factors on safety compliance the study identified “planning, guidelines, policy, management”, “prioritization of proactive measures”, “results in cooperation and information” and “active use of risks assessment document”. In a regression model for the workers, both risk assessment process and contribution measures had a statistically highly significant (p < 0.001) effect on concrete preventive measures. In the regression analysis of the employers risk assessment process had a statistically significant (p < 0.01) effect and contribution measures had a statistically highly significant (p < 0.001) effect on concrete preventive measures.     

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.     

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.     

Method to analyze the regional life loss risk by airborne chemicals released after devastating earthquakes: A simulation approach

Widespread chemical plants render human life more vulnerable to major natural disasters such as earthquakes. Recognizing the potential cascading threats initiated by a devastating earthquake, a general methodology for assessing the life loss risks introduced by airborne hazardous chemical dispersion following seismically induced chemical release (SICR) was proposed. With a 600 km × 600 km region in North China as a demonstrative study area, the dispersion of ammonia released from multiple relevant chemical plants that were supposed to be damaged by a devastating earthquake was simulated in a probabilistic manner. Using an ammonia toxicity-fatality relationship and its toxicity concentration threshold, regional life loss and spatial spread were evaluated. The life loss risk was found to be non-prominent but would be very contingent on unfavorable meteorological conditions. Non-parametric correlation analysis revealed that the respective effects of meteorological mixing parameters on the risk exhibit new features in a disaster context, that is, stronger mixing would cause elevation of risk in a region. This preliminary research implied that the risk of chemical-induced life loss after a devastating earthquake deserves attention and a thorough uncertainty evaluation in the future.     

The typology for allocations of societal risk and safety management tasks at the local governmental level – Framing the current directions in Sweden

The starting point for this article is the need to develop empirical insights about contemporary societal risk and safety management practice and executive structures. In order to facilitate insights about societal risk and safety management in a Scandinavian welfare context we use Sweden and its local governmental level (municipal) as an empirical frame in this paper. The aim for this article is to analyse how a variety of risk and safety management tasks are divided within the Swedish municipalities. The objectives are to frame the current directions for internal allocations of risk and safety issues by providing an empirically based executive typology and to contemplate the implications and future research needs that arise from that management pattern.The analysis is based on statistical analysis of information from a web-survey with chief officials (n = 1283) with responsibilities for different municipal functions and sectors. In this study the responses to one of the survey questions are used for statistical analysis. The analyzed question focused on the degree that the respondents estimated that their administrative sector or function handled a selection of risk and safety management assignments (n = 45). A factor analysis was applied to identify patterns in the dataset. The analysis resulted in an eight factor solution with a high degree of explained variance (74.3%). The results provide an elementary contribution to the understanding of the current societal risks and safety management directions.     

Risk assessment of the ignitability and explosivity of aluminum nanopowders

Previously, an extensive study has been carried out in order to assess the ignition sensitivity and explosivity of aluminum nanopowders. It showed notably that, as the particle size decreases, minimum ignition temperature and minimum ignition energy decrease, indicating higher potential inflammation. However, the explosion severity decreases for diameters lower than 1 μm. As a consequence, this study leads to the conclusions that the ignition sensitivity and explosion severity of aluminum nanopowders may be affected by various phenomena, as pre-ignition, agglomeration/aggregation degree and the intrinsic alumina content. The presence of wall-quenching effects and the predominance of radiation compared to conduction in the flame propagation process have to be discussed to ensure the validity of the 20 L sphere and of the results extrapolation. Based on the peculiar behaviours that had been previously highlighted, a specific risk analysis has been developed in order to assess the fire and explosion risks of such materials. It has been applied to an industrial plant of aluminum nanopowders production. The hazard identification and the consequence modelling steps, especially the quantification of the likelihood and consequences, have been designed specifically. The application of this method has led to the definition of the most adequate safety barriers.     

Occupational accidents model based on risk–injury affinity groups

This article sets outs a generalized utility model for the diagnosis and prediction of accidents among the Spanish workforce. Based on observational data classified into a risk–injury contingency table (19 × 19), we have summarized the accident rate of all Spanish companies over an 11-year period (75,19,732 accidents). By using correspondence analysis a structure composed of three axes can be obtained, the combination of which identifies three separate risk and injury groups, which we use as a general Spanish pattern. The relationships of greater affinity or likelihood amongst the risks and injuries identified in the pattern facilitate decision-making at the risk-assessment stage in Spanish companies. Each risk–injury group has its own characteristics, interpretable within the phenomenological framework of the accident.The main advantage of this model is its potential application to any other country and the feasibility of contrasting results from different countries. One limiting factor, however, is that the model currently lacks a common classification frame for risks and injuries which would enhance this contrast. The aim of this model is to automatically manage work-related accidents at a national level.     

Risk factors associated with sick leave due to work-related injuries in Dutch farmers: an exploratory case-control study

Using data from an insurance company, the occurrence of sick leave among Dutch farmers due to work-related injuries, and the epidemiological risk factors were investigated. In this case-control study the cases had filed a sick leave claim for work-related injury from 1998–2001 and the controls had not filed any claim in this period. Most (74%) of all injuries were work-related. The most frequent types of injury (63%) were bruises, sprains/strains and fractures. Multivariable logistic regression analysis showed that farmers working in dairy farming (OR=2.6) or pig husbandry (OR=2.7), older farmers (OR=1.48 per 10 years) and smokers (OR=1.7) were at increased risk. Within dairy farming, a significant factor was contact with cows (OR=1.7 per 500 h); within pig husbandry, working > 60 h per week was a significant factor (OR=2.2). The population attributable risk was 24% for elimination of smoking, 23% for halving the number of hours' contact with cows in dairy farming and 18% for elimination of a working duration > 60 h per week in pig husbandry. Effective measures to prevent sick leave might be raising awareness that older farmers and smokers are at increased risk, and a focus on the risks of working with animals.     

Experimental simulation of airbag deployment for pipeline closing

Small scale tests were carried out at ISL's shock tube facility STA (100 mm inner diameter) to study the problem of closing a pipeline by means of an airbag in case of explosions or gas leakages. Experiments were carried out to simulate the flow in a pipeline at velocities and gas pressures as present in pipeline flows. In this study the gas used was nitrogen at static pressures of 0.2 up to 5 MPa and at flow velocities of 25 m/s up to 170 m/s. A special Nylon airbag, deployed from the tube wall into the pipe, was used to simulate the airbag inflation in a real pipeline. For this purpose a special gas filling system consisting of a gas generator with a reservoir volume of up to 500 cm³ which permits air pressures up to 17 MPa to be generated inside the airbag was developed at ISL. With a fast pyrotechnically opened valve the reservoir gas was released for airbag filling. The airbag inflation was triggered in such a way that it opened in nearly 3 ms into the pipe flow generated by the shock tube and continued for about 10 ms. For this application a special measuring chamber was designed and constructed with 20 measuring ports. Through two window ports, located one in front of the other, the airbag inflation could be visualized with up to 50 successive flash sparks illuminating a fast rotating film inside a drum camera. Pressure measurements using commercially available PCB pressure gauges at 9 measuring ports placed along the inner tube surface gave some hints on the behaviour of the wall pressure during airbag deployment. As a result from the experiments performed it is to conclude, that, with the Nylon airbag samples available, the pipe flow cannot be blocked by the inflating airbag. The flow forces acting on the airbag during deployment are in the shock tube experiments of the order of about 1000 N, which are not balanced by the airbags' neck, fixing it to the shock tube wall. This outcome suggests that a mechanical support is required to fix the airbag in its place during inflation.     

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.     

Evaluative comparison of two methods for SADT determination (UN H.1 and H.4)

We present our results on the comparison of two methods for the SADT determination. Both methods, UN test H.1 and UN test H.4 are recommended by the international transport regulations from the UN. But during the last years the applicability of the UN test H.4 has been questioned for solid substances. Therefore, three organic peroxides and one self-reactive substance have been investigated in 5 kg and 20 kg packages as well as in the UN test H.4 in a 500 mL Dewar vessel. The SADT values determined with the different methods match. The UN test H.4 seems to be well suited for solid organic peroxides and self-reactive substances of at least 20 kg or 60 L.     

Injury risks in schoolchildren with attention-deficit/hyperactivity or autism spectrum disorder: Results from two school-based health surveys of 6- to 17-year-old children in Sweden

IntroductionInjuries are one of the leading causes of death and disability among children in Sweden and attention-deficit/hyperactivity disorder (ADHD) has previously been associated with an increased risk of injury in pediatric populations elsewhere in the world. Current evidence regarding the possible link between autism spectrum disorder (ASD) and injury risk appears limited, even though some potentially risk-increasing symptoms overlap. The purpose of this study was thus to study the association between both ADHD and ASD concerning the risk of injury among Swedish schoolchildren.MethodsTwo samples were used: a population-based register study containing data from 18,416 children ranging from the ages of 6–17 years collected by school nurses during 2012/2014 (Survey A), and a national cross-sectional study of 3202 ninth-grade children (~ 15 years old) collected from 92 schools in 2011 (Survey B). The data were analyzed using χ²-tests and log-binomial generalized linear models to obtain risk ratios (RR), comparing cases reportedly affected by ADHD or ASD to unaffected controls.ResultsAfter adjusting for confounders, ADHD was associated with a 65% increased risk of injury (RR 1.65 [95% CI: 1.32–2.05] in Survey A, and a 57% increased risk of injury (RR 1.57 [95% CI: 1.27–1.95]) in Survey B. ASD was not significantly associated with any differences in injury risk (RR 0.81 [95% CI: 0.57–1.14]).ConclusionsThe results indicate that there is an elevated injury risk among Swedish schoolchildren with ADHD but not for children with ASD. Future studies should focus on causal mechanisms mediating the association between ADHD and injuries in order to facilitate injury prevention strategies.Practical applicationsParents and teachers of schoolchildren with ADHD should be made aware of the elevated injury risks associated with the diagnosis. Safety experts and injury control professionals should consider the development of specialized prevention strategies in order to reduce these risks.     

Assessing the impact of risk-taking behavior on road crash involvement among University students residing in two Mediterranean countries

Surveillance systems are indispensable for injury prevention; yet, detailed electronic records are rarely available. The “Student’s Health Card” is a self-reporting electronic tool addressing health issues of University students, while aiming to actively involve them in preventive practices and health promotion. Utilizing data from the injury prevention related section, this study sought to investigate the impact of risk-taking behavior on road crash involvement among University students residing in two Mediterranean countries. A total of 978 University students, 451 Greek and 527 Italian, provided information on prior road crash involvement, as well as on eight behavioral variables, comprising a risky behavior score. Multiple logistic regression analysis was performed. The already known tendency for clustering of risky behaviors was evident. One degree increment in the risky behavior score was found to increase the risk of road crash involvement by 35%. Driving after drinking (OR = 2.55, CI = 1.53–4.26), riding with a drunk driver (OR = 2.19, CI = 1.08–4.45) and tobacco smoking (OR = 1.95, CI = 1.18–3.22) significantly multiplied the risk. Despite their better compliance with safety measures, Italian students, compared with Greek, reported worse alcohol-related driving habits and engaged more frequently in mobile phone use while driving. Clustering of risky behaviors was found to be an important predictor of road crash involvement. Screening and awareness of risk-taking propensity of University students could guide early intervention. The “Student’s Health Card” could provide, at minimal cost, reliable risk-taking and road crash involvement information, which is needed for both personal risk assessment and surveillance purposes.     

Using a cluster randomized controlled trial to determine the effects of intervention of battery and hardwired smoke alarms in New South Wales,Australia: Home fire safety checks pilot program

IntroductionIn 2014, Fire & Rescue New South Wales piloted the delivery of its home fire safety checks program (HFSC) aimed at engaging and educating targeted top “at risk” groups to prevent and prepare for fire. This pilot study aimed to assess the effectiveness of smoke alarms using a cluster randomized controlled trial.MethodsSurvey questionnaires were distributed to the households that had participated in the HFSC program (intervention group). A separate survey questionnaire was distributed to the control group that was identified with similar characteristics to the intervention group in the same suburb. To adjust for potential clustering effects, generalized estimation equations with a log link were used.ResultsMultivariable analyses revealed that battery and hardwired smoking alarm usage increased by 9% and 3% respectively among the intervention group compared to the control group. Females were more likely to install battery smoke alarms than males. Respondents who possessed a certificate or diploma (AOR = 1.31, 95% CI 1.00–1.70, P = 0.047) and those who were educated up to years 8–12 (AOR = 1.32, 95% CI 1.06–1.64, P = 0.012) were significantly more likely to install battery smoke alarms than those who completed bachelor degrees. Conversely, holders of a certificate or diploma and people who were educated up to years 8–12 were 31% (AOR = 0.69, 95% CI 0.52–0.93, P = 0.014) and 24% (AOR = 0.76, 95% CI 0.60–0.95, P = 0.015) significantly less likely to install a hardwired smoke alarm compared to those who completed bachelor degrees.ConclusionsThis pilot study provided evidence of the benefit of the HFSC in New South Wales. Practical Applications: Fire safety intervention programs, like HFSC, need to be targeted to male adults with lower level of schooling even when they are aware of their risks.     

Adult opinions about the age at which children can be left home alone, bathe alone, or bike alone: Second Injury Control and Risk Survey (ICARIS-2)

ProblemThis study describes adult opinions about child supervision during various activities.MethodsData come from a survey of U.S. adults. Respondents were asked the minimum age a child could safely: stay home alone; bathe alone; or ride a bike alone. Respondents with children were asked if their child had ever been allowed to: play outside alone; play in a room at home for more than 10 minutes alone; bathe with another child; or bathe alone.ResultsThe mean age that adults believed a child could be home alone was 13.0 years (95% CI = 12.9-13.1), bathe alone was 7.5 years (95% CI = 7.4-7.6), or bike alone was 10.1 years (95% CI = 10.0-10.3). There were significant differences by income, education, and race.DiscussionAssessing adult's understanding of the appropriate age for independent action helps set a context for providing guidance on parental supervision. Guidelines for parents should acknowledge social norms and child development stages.Impact on IndustryKnowledge of social norms can help guide injury prevention messages for parents.     

Rotating biological contactors for wastewater treatment – A review

Rotating biological contactors (RBCs) for wastewater treatment began in the 1970s. Removal of organic matter has been targeted within organic loading rates of up to 120 g m⁻² d⁻¹ with an optimum at around 15 g m⁻² d⁻¹ for combined BOD and ammonia removal. Full nitrification is achievable under appropriate process conditions with oxidation rates of up to 6 g m⁻² d⁻¹ reported for municipal wastewater. The RBC process has been adapted for denitrification with reported removal rates of up to 14 g m⁻² d⁻¹ with nitrogen rich wastewaters. Different media types can be used to improve organic/nitrogen loading rates through selecting for different bacterial groups. The RBC has been applied with only limited success for enhanced biological phosphorus removal and attained up to 70% total phosphorus removal. Compared to other biofilm processes, RBCs had 35% lower energy costs than trickling filters but higher demand than wetland systems. However, the land footprint for the same treatment is lower than these alternatives. The RBC process has been used for removal of priority pollutants such as pharmaceuticals and personal care products. The RBC system has been shown to eliminate 99% of faecal coliforms and the majority of other wastewater pathogens. Novel RBC reactors include systems for energy generation such as algae, methane production and microbial fuel cells for direct current generation. Issues such as scale up remain challenging for the future application of RBC technology and topics such as phosphorus removal and denitrification still require further research. High volumetric removal rate, solids retention, low footprint, hydraulic residence times are characteristics of RBCs. The RBC is therefore an ideal candidate for hybrid processes for upgrading works maximising efficiency of existing infrastructure and minimising energy consumption for nutrient removal. This review will provide a link between disciplines and discuss recent developments in RBC research and comparison of recent process designs are provided (Section 2). The microbial features of the RBC biofilm are highlighted (Section 3) and topics such as biological nitrogen removal and priority pollutant remediation are discussed (Sections 4 Biological nutrient removal in RBCs, 5 Priority pollutant remediation in RBCs). Developments in kinetics and modelling are highlighted (Section 6) and future research themes are mentioned.     

Synthesis of CuO nanoparticles through green route using Citrus limon juice and its application as nanosorbent for Cr(VI) remediation: Process optimization with RSM and ANN-GA based model

In present investigation, an attempt has been made for the synthesis of cupric oxide nanoparticles (CuONPs) through a green route by utilizing lemon juice extract as a bioreductant. The synthesized CuONPs were characterized through UV–visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The CuONPs were utilized for Cr(VI) removal from water through adsorption method in batch mode at different initial Cr(VI) concentration, pH, temperature and CuONPs dosage. The maximum uptake capacity of CuONPs was found to be 16.63 mg of Cr(VI)/g at pH 4.0. Implementation of response surface methodology (RSM) followed by artificial neural network hybridized with genetic algorithm (ANN-GA) approach has resulted maximum Cr(VI) adsorption of 98.8% under the optimized conditions of initial metal concentration 22.5 mg/L, pH 3.81, CuONPs dose 1.28 g/L and temperature 37.1 °C. Under optimum conditions, adsorption isotherm study was conducted, which showed that the fitness of experimental data was well achieved with Langmuir isotherm model illustrating monolayer pattern of adsorption. Thermodynamic study revealed that the process was spontaneous and endothermic in nature, while adsorption kinetics was best explained by pseudo-second order kinetic model.