Prevalence of work-site injuries and relationship between obesity and injury among U.S. workers: NHIS 2004–2012

Introduction: Studies have reported associations between obesity and injury in a single occupation or industry. Our study estimated the prevalence of work-site injuries and investigated the association between obesity and work-site injury in a nationally representative sample of U.S. workers. Methods: Self-reported weight, height, and injuries within the previous three months were collected annually for U.S. workers in the National Health Interview Survey (NHIS) from 2004–2012. Participants were categorized as normal weight (BMI: 18.5–24.9 kg/m²), overweight (BMI: 25.0–29.9), obese I (BMI: 30.0–34.9), and obese II (BMI: 35 +). The prevalence of injury and prevalence ratios from fitted logistic regression models was used to assess relationships between obesity and injury after adjusting for covariates. Sampling weights were incorporated using SUDAAN software. Results: During the 9-year study period from 2004 to 2012, 1120 workers (78 workers per 10,000) experienced a work-related injury during the previous three months. The anatomical sites with the highest prevalence of injury were the back (14.3/10,000 ± 1.2), fingers (11.5 ± 1.3), and knees (7.1 ± 0.8). The most common types of injuries were sprains/strains/twists (41.5% of all injuries), cuts (20.0%), and fractures (11.8%). Compared to normal weight workers, overweight and obese workers were more likely to experience work-site injuries [overweight: PR = 1.25 (95% CI = 1.04–1.52); obese I: 1.41 (1.14–1.74); obese II: 1.68 (1.32–2.14)]. These injuries were more likely to affect the lower extremities [overweight: PR = 1.48, (95% CI = 1.03–2.13); obese I: 1.70 (1.13–2.55); obese II: 2.91 (1.91–4.41)] and were more likely to be due to sprains/strains/twists [overweight: PR = 1.73 (95% CI = 1.29–2.31); obese I: PR = 2.24 (1.64–3.06); obese II: PR = 2.95 (2.04–4.26)]. Conclusions: Among NHIS participants, overweight and obese workers were 25% to 68% more likely to experience injuries than normal weight workers. Practical applications: Weight reduction policies and management programs may be effectively targeted towards overweight and obese groups to prevent or reduce work-site injuries.     

Characterization of heavy metals in fly ash from municipal solid waste incinerators in Shanghai

This study aims to develop a methodology for analysis of characteristics of heavy metals in MSWI fly ash. It performed analysis of composition of heavy metals, leaching toxicity, leaching behavior as a function of pH, specification distribution and corresponding mineral components of residue derived from each step of the sequential extraction. It is found that content of heavy metals follows the sequence of Zn > Pb > Cu > Cr > As > Ni > Cd approximately Hg in both plants, and that total heavy metals account for less than 1% by mass of fly ash. Major hazardous heavy metals in fly ash are As, Cd, Hg, Pb and Zn, whose leaching ratios exceed the limit value described in hazardous waste identification standard. Measured leaching results of Cu, Pb and Zn are essentially consistent with the simulated results at pH between 0 and 13. Content of calcium-silicates, alumino-silicates and glass phases in residue derived from sequential extraction procedure increases steadily from the first step to the fifth step of the sequential extraction procedure. Cu, As, Cr, Hg, Cd, and Ni, relatively stable under strong basic conditions, can be leached out under strong acidic conditions, while Zn and Pb tend to be leached out under both strong acidic and basic conditions.     

Prevalence and demographic differences in microaccidents and safety behaviors among young workers in Canada

IntroductionThe present study examines the self-reported frequency of non-lost work time workplace injuries (“microaccidents”) and the frequency of three types of work-related safety behaviors (i.e., safety voice, safety compliance, and safety neglect) recalled over a four-week period.MethodWe analyzed data on microaccidents and safety behaviors from 19,547 young workers (aged 15–25 years, Mdn = 18 years; 55% male) from multiple Canadian provinces.ResultsApproximately one-third of all young workers recalled experiencing at least one microaccident at work in the last four weeks. Comparisons across three age groups revealed that younger workers, particularly between the ages of 15–18, reported more frequent microaccidents, less safety voice, less safety compliance, and more safety neglect than workers aged 19–22. This pattern of results also held for comparisons between workers in 19–22 and 23–25 age groups, except for safety voice which did not differ between these two older age groups. In terms of gender, males and females reported the same frequency of microaccidents, but males reported more safety voice, more safety compliance, and more safety neglect than females did. The results and limitations of the present study are discussed.ConclusionFrequency of microaccidents and safety behavior vary among young worker age sub-groups.     

Characterization of fall patients: Does age matter?

IntroductionEvaluating age-specific fall characteristics is important for prevention programs. The aim was to characterize fallers who presented to our trauma center. We hypothesized that fall characteristics and outcomes would vary with age.MethodsData were retrospectively collected from the trauma registry and electronic medical records during January 1st, 2014-December 31st, 2015. Data were analyzed by Chi-square test with Yates’ continuity correction and one-way ANOVA with Bonferroni’s multiple comparisons test.ResultsThere were 1541 fallers, 814 (52.8%) were male. Ages ranged from 11 months to 100 years. The admission rate was high at 86%, with an average hospital stay of 5.7 days. Patients in the 0-18 and 19-45 age groups spent significantly less time in the hospital (p < 0.0001). Elderly patients had the highest average injury severity score (p < 0.0001). However, the youngest patients required surgery more often (p = 0.0004). The overall mortality rate was 3.6% and 52.8% were male. The mortality rate increased with age, from 0% for the 0-18 age group to 6.9% for patients ≥ 65 years of age. Remarkably, fallers in the 19-45 and 46-64 age groups predominantly died from ground level falls even though the average fall height in these groups was the highest (p < 0.0001). More fallers in the 19-45 and 46-64 age groups tested positive for alcohol/drug use (p < 0.0001). Middle-aged and elderly patients were more likely to be discharged to a skilled nursing or rehabilitation facility compared to younger patients who were discharged home.Conclusions and practical applicationsFall characteristics and outcomes varied with age. Data on age-specific characteristics, outcomes, and risk factors of falls will help in developing targeted interventions and may lead to better approaches to treat patients.     

Work-safety tension, perceived risk, and worker injuries: a meso-mediational model

IntroductionWork-safety tension arises when workers perceive that working safely is at odds with effectively doing their jobs. We proposed that workers’ perceptions of work-safety tension would be associated with higher levels of perceived risk, which would, in turn, relate to worker injuries on the job.MethodGrocery store workers (n = 600) completed an online survey and organizational worker injury reports were obtained for a two-year period following the survey. Survey results were linked to subsequent worker injuries using hierarchical generalized linear modeling.ResultsWe found support for the proposed meso-mediation model: department work-safety tension predicted subsequent worker injuries, partially through an association with workers’ risk perceptions.ConclusionsSafety researchers and consultants and organizational leaders should look beyond typically-examined safety climate constructs, such as management commitment to safety, and pay particular attention to workers’ perceptions of work-safety tension.     

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.     

Experimental study of the characteristics of solid fuel from fry-dried swine excreta

Swine excreta were dried by boiling via immersion in hot oil. In this method, moisture in the excreta is replaced with oil or evaporated by turbulent heat transfer in high-temperature oil. The dried excreta can be used in an incinerator like low-rank coal or solid fuel. Refined waste oil and B–C heavy oil were used for drying. Drying for 8 min at 150 °C reduced the water content of raw excreta from 78.90 wt.% to 1.56 wt.% (refined waste oil) or 1.62 wt.% (B–C heavy oil) and that of digested excreta from 79.58 wt.% to 3.40 wt.% (refined waste oil) or 3.48 wt.% (B–C heavy oil). The low heating values of the raw and digested excreta were 422 kJ/kg and ?2,713 kJ/kg, respectively, before drying and 27,842–28,169 kJ/kg and 14,394–14,905 kJ/kg, respectively, after drying. A heavy metal analysis did not detect Hg, Pb, Cd, As, and Cr in the dried excreta, but Al, Cu, and Zn, which occur in the feed formula, were detected. Thermogravimetric analysis before and after drying revealed that emission of volatiles and combustion of volatiles and fixed carbon occurred at temperatures of 250–500 °C when air was used as the transfer gas.     

Autoignition temperature data and scaling for amide solvents

Autoignition temperature tests using the ASTM E659 test method have been conducted for N,N-dimethylacetamide (DMAC) and N,N-dimethylformamide (DMF) in test vessels with volumes of 0.5 l, 5 l, and 12 l. Tests were conducted at three different laboratories yielded good agreement (standard deviation with 5 °C) in all cases except for DMAC in the 0.5 l test vessel (standard deviation of 23 °C). Scaling correlations have been developed for the decrease of autoignition temperature with increasing volume and for increasing values of the vessel volume to surface area ratio. The variations for DMAC are steeper than the literature values for almost all other combustible liquids. Cool flames were observed for DMAC at temperatures as much as 44 °C below the autoignition temperature and for DMF at temperatures as much as 171 °C below its autoignition temperature. The DMF cool flame temperatures in the 5-l and 12-l test vessels are approximately equal to the DMF autoignition temperature in a closed 12-l test vessel. Gas samples taken after the cool flame and hot flame tests reveal the presence of high concentrations of diamines and dimethylamino acetonitrile, and small concentrations of many other partial decomposition/oxidation components.     

Demographic determinants of chemical safety information recall in workers and consumers in South Africa: A cross sectional study

BackgroundChemical hazard communication is intended to alert users of the potential hazards of chemicals. Hazard information needs to be understood and recalled. Recall of hazard communication is critical when the written form of the information is not available at the time it is required.MethodsA cross-sectional study investigating associations between recall of chemical safety information on labels amongst 402 participants including 315 workers and 87 consumers in two provinces of South Africa.ResultsRespondents were predominantly male (67.7%), the median age was 37 years (IQR: 30-46 years) and less than half of the participants completed high school (47.5%). Multivariate analysis identified the following positive associations with the recall of all the label elements listing the strongest association: call appropriate services and industrial vs consumer sector (OR = 2.4; 95% CI: 1.2; 4.6 ); call appropriate services and transport vs consumer sector (OR = 4.4; 95% CI: 1.2; 16.0); flammable symbol and male vs female gender (OR = 2.3; 95% CI: 1.0; 5.3); flammable symbol and home language English vs African languages (OR = 6.6; 95% CI: 2.1; 21.2); any hazard statement and home language Afrikaans vs African languages (OR = 14.0; 95% CI: 3.6; 54.2), any first aid statement and further education vs none (OR = 3.3; 95% CI: 1.3; 8.0), correct chemical name and industry blue collar workers vs non-industry blue collar workers (OR = 2.6; 95% CI: 1.1; 6.1), correct chemical name and non-industry white collar occupations vs non-industry blue collar workers (OR = 2.7; 95% CI: 1.0; 7.1).ConclusionThe study found a number of potential positive associations which influence recall of label elements of which some (e.g., sector, gender, occupation) suggest further research. Relevant policies in South Africa should ensure that the safety information on chemical labels is clearly visible to read and understandable which aids recall and the reduction in harmful chemical exposures.     

Drop in dry mass and organic substance content in the process of autothermal thermophilic aerobic digestion

This paper presents the results of a study of a sludge subjected to the (ATAD) process – Autothermal Thermophilic Aerobic Digestion occurring in a two-stage installation operated in a municipal wastewater treatment plant in Olecko, Poland. The study of the sludge and the analysis of obtained results were conducted over 2011 and 2014. The subject of the study was a thickened sludge in an intermediate tank from which it was next transferred to facility reactors. The stabilization of processed sludge was evaluated analyzing the change in the dry mass (DS) content in the sludge. Measurements were carried out in thickened sludge samples and after the ATAD process. Collected results were then subjected to a statistical analysis and it was determined to which extent as resulted from the subject process the dry mass and the dry organic mass (VS) content was changing in the sludge. Also, it was analyzed how the oxygen chemical demand (COD) was changing. The dry mass content in the thickened sludge was from 60 g/l to 160 g/l. After the process, this amount was from 35 to 76 g/l. Similarly, the organic mass content in a dry sludge mass changed from initial values within a range of 44–135 g/l to 23–60 g/l after the ATAD process. Also, the organic substance content expressed as COD decreased from 80 to 467 g O₂/l in a thickened sludge to 51–261 g O₂/l in the sludge after the process. The article presents conclusions from the result of the conducted study as well as personal experience.     

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.     

Prevention of occupational injuries: Evidence for effective good practices in foundries

IntroductionOccupational injuries are a relevant research and practical issue. However, intervention studies evaluating the effectiveness of workplace injury prevention programs are seldom performed. Method: The effectiveness of a multifaceted intervention aimed at reducing occupational injury rates (incidence/employment-based = IR, frequency/hours-based = FR, severity = SR) was evaluated between 2008 and 2013 in 29 Italian foundries (22 ferrous; 7 non-ferrous; 3,460 male blue collar workers/year) of varying sizes. Each foundry established an internal multidisciplinary prevention team for risk assessment, monitoring and prevention of occupational injuries, involving employers, occupational physicians, safety personnel, workers' representatives, supervisors. Targets of intervention were workers, equipment, organization, workplace, job tasks. An interrupted time series (ITS) design was applied. Results: 4,604 occupational injuries and 83,156 lost workdays were registered between 2003 and 2013. Statistical analysis showed, after intervention, a reduction of all injury rates (− 26% IR, − 15% FR, −18% SR) in ferrous foundries and of SR (− 4%) in non-ferrous foundries. A significant (p = 0.021) ‘step-effect’ was shown for IR in ferrous foundries, independent of secular trends (p < 0.001). Sector-specific benchmarks for all injury rates were developed separately for ferrous and non-ferrous foundries. Conclusions: Strengths of the study were: ITS design, according to standardized quality criteria (i.e., at least three data points before and three data points after intervention; clearly defined intervention point); pragmatic approach, with good external validity; promotion of effective good practices. Main limitations were the non-randomized nature and a medium length post-intervention period. In conclusion, a multifaceted, pragmatic and accountable intervention is effective in reducing the burden of occupational injuries in small-, medium- and large-sized foundries. Practical Applications: The study poses the basis for feasible good practice guidelines to be implemented to prevent occupational injuries, by means of sector-specific numerical benchmarks, with potentially relevant impacts on workers, companies, occupational health professionals and society at large.     

Effects of time-gap settings of adaptive cruise control (ACC) on driving performance and subjective acceptance in a bus driving simulator

A study was conducted to investigate the effects of time-gap settings and contents of secondary tasks on a fix-based bus driving simulator on drivers’ performance while reclaiming control from ACC in a car-following scenario of emergency brake by the lead vehicle. Thirty professional bus drivers drove on the simulator with the scenario of highway traffic flow under 12 random time-gap settings: from 0.64 s to 2.40 s with the interval of 0.16 s. As for the effects of secondary tasks, subjects were evenly divided into three conditions: no secondary task interference, simple secondary task, and complex task. The results demonstrated that different safety demarcations of time-gaps on subjective acceptance and driving performance can be found out. The integrated demarcations separated time-gaps into divisions that represented different levels of danger. It revealed that the safer time-gaps for different situations were: longer than 1.60 s for none-secondary task distraction and longer than 2.08 s for being continuously distracted by secondary tasks. The demand for simple tasks is relatively high, so a larger time-gap is needed for the driver to remain safe. This research has implications for the time-gap selection of ACC and effects of secondary task distraction on buses. A next logical step will focus on determining time-gaps for lead vehicles on curves or slopes, when multiple vehicles are present ahead, and modeling driver behavior and performance with ACC for cars, buses, and other types of vehicles.     

How perceptions of experience-based analysis influence explanations of work accidents

IntroductionThis article looks into how perceptions of experience-based analysis (EBA) influence causal explanations of accidents given by managers and workers in the chemical industry (n = 409) and in the nuclear industry (n = 222).MethodThe approach is based on the model of naive explanations of accidents (Kouabenan, 1999, 2006, 2009), which recommends taking into account explanations of accidents spontaneously given by individuals, including laypersons, not only to better understand why accidents occur but also to design and implement the most appropriate prevention measures. The study reported here describes the impact of perceptions about EBA (perceived effectiveness, personal commitment, and the feeling of being involved in EBA practices) on managers' and workers' explanations of accidents likely to occur at the workplace.ResultsThe results indicated that both managers and workers made more internal explanations than external ones when they perceived EBA positively. Moreover, the more the participants felt involved in EBA, were committed to it, and judged it effective, the more they explained accidents in terms of factors internal to the workers. Practical Applications: Recommendations are proposed for reducing defensive reactions, increasing personal commitment to EBA, and improving EBA effectiveness.     

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.     

A field assessment of floor slipperiness in a fish market in Taiwan

A field assessment of floor slipperiness in 10 fish stands in a fish market in Taiwan was conducted using both friction measurements and subjective ratings. The friction measurements were conducted using the Portable Skid Resistance Tester (PSRT). The subjective ratings of floor slipperiness of both the workers and the customers were collected. The friction measurement results showed that the sink areas had both the lowest friction values and subjective ratings. The overall friction measurement results and the subjective ratings were in fair agreement (r = 0.46 and ρ = 0.49). The customers perceived the walkways as somewhere between “very slippery” to “somewhat slippery” and the picking-up areas as “very slippery.” These were different from the perceptions of the workers where they perceived both areas as “somewhat slippery.”     

Effects of high ammonia loads on nitrogen mass balance and treatment performance of a biotrickling filter

A biotrickling filter packed with coal slag as packing medium was continuously used for more than 9 months under high ammonia loading rates of up to 140 g/m³/h. Nitrogen mass balance and microbial community analysis were conducted to evaluate the inhibitory effects of high ammonia concentration and metabolic by-products on the rates of nitrification. Ammonia removal efficiency reached above 99% at an empty bed retention time of as low as 8 s when inlet concentrations were below 350 ppm. The maximum and critical elimination capacities of the biotrickling filter were 118 g/m³/h and 108.1 g/m³/h, respectively. Kinetics analysis results showed that less than 2.5 s was required for the biotrickling filter with pH control to treat ammonia at concentrations of up to 500 ppm in compliance with the Taiwan EPA standard (outlet NH₃ < 1 ppm). Results of mass balance and microbial community analysis indicated that complete removal was mainly contributed by the activities of autotrophic ammonia oxidizing bacteria and not by physical absorption or adsorption at low loading rates. However, at high inlet loadings, ammonium became the dominant by-product due to inhibitory effects of high ammonia concentration on the bacterial community.     

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.     

Explosibility of cork dust in methane/air mixtures

Explosibility studies of hybrid methane/air/cork dust mixtures were carried out in a near-spherical 22.7 L explosibility test chamber, using 2500 J pyrotechnic ignitors. The suspension dust burned as methane/air/dust clouds and the uniformity of the cork dust dispersion inside the chamber was evaluated through optical dust probes and during the explosion the pressure and the temperature evolution inside the reactor were measured. Tested dust particles had mass median diameter of 71.3 μm and the covered dust cloud concentration was up to 550 g/m³. Measured explosions parameters included minimum explosion concentration, maximum explosion pressures and maximum rate of pressure rise. The cork dust explosion behavior in hybrid methane/air mixtures was studied for atmospheres with 1.98 and 3.5% (v/v) of methane. The effect of methane content on the explosions characteristic parameters was evaluated. The conclusion is that the risk and explosion danger rises with the increase of methane concentration characterized by the reduction of the minimum dust explosion concentration, as methane content increases in the atmosphere. The maximum explosion pressure is not very much sensitive to the methane content and only for the system with 3.5% (v/v) of methane it was observed an increase of maximum rate of pressure rise, when compared with the value obtained for the air/dust system.