NIOSH Research Articles

A longitudinal pre-post study: An evaluation of the Department of the Air Force bundled occupational fall prevention efforts.

Fall injuries are the second leading cause of traumatic injury and death for all US workers and are a leading injury concern for the Department of the Air Force (DAF). Bundled interventions can improve the likelihood of injury reduction, especially in large, heterogeneous working populations. In 2013, the DAF implemented the "Air Force Fall Prevention Focus," a bundled intervention of prevention efforts designed to reduce occupational fall injury events among DAF members. The purpose of this study is to describe the burden and risk factors associated with fall injuries and evaluate the effectiveness of the Fall Prevention Focus in reducing the burden of fall injuries. The National Institute for Occupational Safety and Health (NIOSH) partnered with the US Air Force Safety Center (AFSEC) to examine the impact of the Fall Prevention Focus as a bundled intervention. Injury events included a narrative description of the injury event, demographics, work environment, job tasks, and other structured details. Descriptive statistics and pre-post longitudinal modeling were used to evaluate changes in fall injury rates. The Fall Prevention Focus Implementation (2013-2018) resulted in an annual 10.4% (95% confidence interval [CI]: 8.5%, 12.2%) reduction, and a 6-year cumulative 48.3% (95% CI: 41.4%, 54.3%) reduction in fall injury event rates by 2018. Safety in the DAF involves a comprehensive approach. Documenting the impact of the Fall Prevention Focus may help translate these findings to improve fall prevention efforts in other sectors of the military and high fall-risk industries in the private sector, such as construction.

In silico occupational exposure banding framework for data poor compounds in biotechnology.

Occupational exposure limits (OELs) and occupational exposure bands (OEBs) provide quantitative benchmarks for worker health protection. If empirical toxicology data are insufficient to derive an OEL, an OEB is often assigned using partial toxicology data along with other relevant hazard information. There is no consensus methodology to assign OEBs for chemicals lacking any empirical toxicology data. Thus, this study developed an in silico framework for OEB assignment of data poor compounds. It relies upon computational tools to evaluate standard toxicological end points and to assign reliability ratings, which are then used to assign Global Harmonization System (GHS) hazard categories. Subsequently, the hazard categories are entered into the National Institute for Occupational Safety and Health (NIOSH) occupational exposure banding tool to assign bands for individual end points as well as an overall OEB. As a proof-of-concept, five compounds with established OELs (i.e., "knowns") were evaluated. The knowns were assigned to overall OEBs C, D, or E, four of which were equal to or lower than the OEBs based on actual harmonized GHS categories as well as established OELs, indicating that the OEBs assigned using this framework are likely to be protective. Subsequently, five compounds with little to no experimental data and no established OELs from any U.S. agency or consensus OEL-setting organizations were evaluated (i.e., "unknowns"). The unknowns were assigned to overall OEBs D or E. It was concluded that the proposed framework can be used to assign protective OEBs to compounds with little to no toxicology testing data. As additional data become available, the compound may be de-risked, and a precautionary OEB (or an OEL) can be assigned. The proposed framework provides an example of a practical methodology to evaluate data poor compounds and shows that the output of this framework is expected to be protective of worker health.

Fit Testing Failure of Reprocessed "Duckbill"-Type N95 Masks.

In response to worldwide shortages of N95 masks during the severe acute respiratory syndrome-coronavirus-2 pandemic, various strategies have been used. The Centers for Disease Control and Prevention recommend several strategies, including simple isolation to reprocessing methods using vaporized hydrogen peroxide to guide reuse of masks up to five times. National Institute for Occupational Safety and Health (NIOSH) quantitative fit testing was performed after five trials of donning and doffing in one cohort of new masks and two cohorts of repeatedly sterilized "duckbill"-type N95 masks. One cohort of new masks and two cohorts of sterilized masks were repeatedly subjected to 35% vaporized hydrogen peroxide for either five or 10 cycles. Then, they were subjected to five trials of donning and doffing, with NIOSH quantitative fit testing performed after each wear cycle to assess for any degradation on fit performance caused by sterilization and/or repeated donning and doffing up to the recommended Centers for Disease Control and Prevention limit of five times. All of the fit testing was performed on a single volunteer. The means and 95% confidence intervals for each cohort and the individual results for each mask within each cohort were reported. A χ2 analysis showed significant differences in percentages of masks that pass fit testing in both recycled mask cohorts. These data show the variability of NIOSH fit testing results of both new and sterilized masks. The mask recycling program of our partner health systems thus discarded these types of masks due to the variable failure rate. Health systems should consider individual evaluation to inform their overall policies on mask reuse and recycling.

Evaluation of exposure to volatile organic compounds (BTEX) and Polycyclic Aromatic Hydrocarbons (PAHs) in gas station workers and oxidative stress assessment in Karaj city

Gas stations are one of the sources of benzene, toluene, ethylbenzene and xylene (BTEX) and polyromantic hydrocarbons (PAHs). The present study was conducted with the aim of evaluating the level of breathing exposure of gas station workers to BTEX, PAHs and oxidative stress caused by exposure to these compounds in Karaj city. Oxidative stress and reactive oxygen species (ROS) is one of the mechanisms involved in the toxicity caused by exposure to gas vapors. In this study, all 25 gas stations in the city of Karaj were investigated. Personal sampling and analysis of BTEX and PAHs was done according to National Institute for Occupational Safety and Health (NIOSH) 1501 and 5515 methods, respectively. Finally, oxidative stress markers were investigated in 25 gas station workers and 25 control group. The results showed that the mean age and employment history of gas station workers are 39.96 ± 9.55 and 12.84 ± 6.92, respectively. Also, no significant difference was reported between gas station workers and control subjects in terms of oxidative stress parameters including the level of ROS, oxidized glutathione (GSSG) content, malondialdehyde (MDA) and reduced glutathione (GSH) content. The concentration values of personal exposure of gas station workers to BTEX and PAHs are lower than the occupational exposure limits (OEL). Although the level of oxidative stress parameters in gas station workers is higher than the control group, this difference is not statistically significant (p>0.05). It is recommended to take personal protection measures in case of chronic exposure.

Surgeons Who Perform Total Hip Arthroplasty Are at Risk for Noise-Induced Hearing Loss, Especially When Using Automated Broaching.

Noise-induced hearing loss (NIHL) is a serious concern for orthopedic surgeons. The National Institute for Occupational Safety and Health (NIOSH) sets the safe exposure limit at 85 dB for 8 hours, yet operating rooms often surpass this limit. This study investigated if using an automated broaching system exposes orthopedic surgeons to dangerous decibel (dB) levels. A prospective study analyzed 138 intraoperative sound recordings from 92 total hip arthroplasty (THA) surgeries and 46 baseline measurements at an academic-affiliated private practice, using the NIOSH Sound Level Meter (SLM) application and a microphone. The surgeries were categorized into manual and automated broaching. Key metrics measured included maximal dB level (MDL), peak sound pressure (LCpeak), average continuous sound (LAeq), and average weighted sound in an 8-hour period (TWA), along with dose representations, to identify hazardous noise levels. Of the 92 THA sound recordings, 50 used manual broaching and 42 employed automated broaching. Automated broaching exhibited higher noise levels, with an average MDL of 109.92 dBA, a LAeq of 86.09 dBA, a TWA of 76.48 dBA, and a projected noise dose of 137.74%. In contrast, manual broaching exhibited an average MDL of 105.87 dBA, a LAeq of 83.06 dBA, a TWA of 72.82 dBA, and a projected noise dose of 82.02%. This study highlights the auditory risks from automated broach and manual THA surgeries that orthopedic surgeons experience. Manufacturers should focus on reducing instrument noise when designing surgical tools and orthopedic surgeons and operating room staff should take measures to protect themselves from NIHL during surgery. [Orthopedics. 202x;4x(x):xx-xx.].

The Use of Injury and Fatality Narratives to Convey Agricultural Safety and Health Messages and to Develop Effective Resources Through Collaborative, Multi-Disciplinary Approaches (Tell a Story, Save a Life)

ABSTRACT Objective Storytelling engages audiences, passes down traditions and history, educates, and helps people understand and interpret their environment. Many of those who work in agriculture have been part of the storytelling tradition since childhood. Research has demonstrated the emotional impact of personal stories and how prevention information is conveyed effectively “farmer to farmer” through this method of communication. Methods Since 2016, the Telling the Story Project has provided a space for those directly or indirectly involved in an agricultural incident to share their story and unique perspectives on how similar incidents can be avoided. Results This collaborative project, developed between the National Institute for Occupational Safety and Health (NIOSH) Agriculture Safety Centers, has resulted in 11 stories on a dedicated website, safety and health resources, and educational guides. The stories and educational guidelines have been marketed extensively through traditional and social media sources, employed in safety training, and embraced by educators in agricultural programs. The website has provided a national and international reach with more than 35,000 visits. Conclusion Qualitative thematic analysis of the stories provided data on the circumstances leading up to each incident, valuable information on how the storytellers interpreted the aftermath, and a novel perspective on how safety professionals can create messaging that will resonate with the farming community.

DNA damage in workers exposed to mineral oils

Mineral oils, untreated or mildly treated, have been classified in group 1 as a potential source of cancer by the International Agency for Research on Cancer (IARC). Although numerous studies have implicated metalworking fluids (MWFs) as human carcinogens, toxicology data regarding the mechanism of carcinogenicity are limited. This study is intended to examine the systemic effects of machining workers’ exposure to MWFs. The potential toxicity of mineral oils was investigated in 65 lathe workers compared to controls (66 men). The occupational exposure was measured by the National Institute for Occupational Safety and Health (NIOSH) 5026. The DNA damage has been examined by the comet assay method. According to the field assessments, the time-weighted average (TWA) exposure to mineral oil mist was 7.67 ± 3.21 mg/m3. A comet assay of peripheral blood cells showed that tail length (TL) and olive moment (OM) were significantly higher in the exposed group (p < 0.05). A multiple logistic regression analysis revealed that, within subjects with over 10 years of exposure, the odds ratio of worker with high TL, percent of DNA in tail, OM, and tail moment (TM) were 1.68, 1.41, 1.71, and 2.71, respectively. DNA strand break in exposed workers was associated with higher exposure time in years. Mineral oil toxicity could be altered in the presence of by-products and impurities. For a better understanding of genotoxicity, further studies are required.

Creatinine clearance is maintained in a range of wet-bulb globe temperatures and work-rest ratios during simulated occupational heat stress.

We tested the hypothesis that compliance with the National Institute for Occupational Safety and Health (NIOSH) heat stress recommendations will prevent reductions in glomerular filtration rate (GFR) across a range of wet-bulb globe temperatures (WBGTs) and work-rest ratios at a fixed work intensity. We also tested the hypothesis that noncompliance would result in a reduction in GFR compared with a work-rest matched compliant trial. Twelve healthy adults completed five trials (four NIOSH compliant and one noncompliant) that consisted of 4 h of exposure to a range of WBGTs. Subjects walked on a treadmill (heat production: approximately 430 W) and work-rest ratios (work/h: 60, 45, 30, and 15 min) were prescribed as a function of WBGT (24°C, 26.5°C, 28.5°C, 30°C, and 36°C), and subjects drank a sport drink ad libitum. Peak core temperature (TC) and percentage change in body weight (%ΔBW) were measured. Creatinine clearance measured pre- and postexposure provided a primary marker of GFR. Peak TC did not differ among NIOSH-compliant trials (P = 0.065) but differed between compliant versus noncompliant trials (P < 0.001). %ΔBW did not differ among NIOSH-compliant trials (P = 0.131) or between compliant versus noncompliant trials (P = 0.185). Creatinine clearance did not change or differ among compliant trials (P ≥ 0.079). Creatinine clearance did not change or differ between compliant versus noncompliant trials (P ≥ 0.661). Compliance with the NIOSH recommendations maintained GFR. Surprisingly, despite a greater heat strain in a noncompliant trial, GFR was maintained highlighting the potential relative importance of hydration.NEW & NOTEWORTHY We highlight that glomerular filtration rate (GFR) is maintained during simulated occupational heat stress across a range of total work, work-rest ratios, and wet-bulb globe temperatures with ad libitum consumption of an electrolyte and sugar-containing sports drink. Compared with a work-rest matched compliant trial, noncompliance resulted in augmented heat strain but did not induce a reduction in GFR likely due to an increased relative fluid intake and robust fluid conservatory responses.

Test method for evaluating the NIOSH Noise Mapper application in a hemi-anechoic chamber

The Noise Mapper Application developed by the National Institute for Occupational Safety and Health (NIOSH) can be used to identify areas in the workplace where workers may be exposed to hazardous noise. The app was created to empower workers to measure sound levels in their workplace, make informed decisions about noise exposure, and prevent occupational hearing loss. To evaluate the maps generated by the app, a single sound source or multiple sources were used to generate steady state sound fields within the NIOSH hemi-anechoic chamber (HAC). A sound level meter (Larson Davis, Model 831C) was used to measure A-weighed equivalent continuous sound levels on a grid with a spacing of 1.5 m (5 ft). The NIOSH Noise Mapper app was then used to generate sound level contour plots with a grid spacing of 3.0 m (10 ft). The accuracy of the map was evaluated by comparing the predicted sound levels with the measured sound levels. The results show the app can estimate the sound levels to within ±1.2 dB(A) of the measured values. The test method used to evaluate the NIOSH Noise Mapper app and the results of the comparison will be discussed in this paper.

Creating noise contour maps utilizing the NIOSH Noise Mapper App (A pilot study)

High noise levels can lead to physical and psychological stress, reduced productivity, and permanent hearing loss in workers. Traditional noise monitoring techniques indicate that mine workers, for example, consistently have a higher level of noise exposure when compared to workers in other heavy industries. It is critical to conduct risk assessments, identify noise sources, and control them to prevent occupational noise-induced hearing loss (ONIHL). The National Institute for Occupational Safety and Health (NIOSH) has recently developed the smartphone-based NIOSH Noise Mapper Application, which generates a noise contour map to enable individuals, workers, and hearing conservation professionals to apply the hierarchy of controls for optimized prioritization and focused targeting of the most effective hearing conservation interventions. Preliminary testing of the Noise Mapper app has been carried out in a hemi-anechoic chamber at the NIOSH Mining Laboratory in Pittsburgh. The results demonstrate that the Noise Mapper app can quickly and cost-effectively generate adequate noise contour maps to identify noise hazards and relevant noise-generating machinery to prioritize and target the most effective interventions. However, additional testing is needed to evaluate the Noise Mapper app's performance in real-world environments and its ability to measure multiple sound sources. This new tool supplements, but does not, replace traditional methods of creating noise contour maps.

Power saw noise levels during steel stud cutting tasks on commercial construction sites: a tool characterization from a worker exposure standpoint.

Construction framers who cut and install steel studs as part of their daily tasks are exposed to hazardous noise levels during their work shift in large part due to the power saws they use to cut steel studs. This investigation characterized the sound pressure levels of power saws used to cut steel studs on active construction sites. Further, the length of time it took to cut various studs on a construction site was investigated to understand worker exposure times to saw noise. In general, power saws used on the study sites to cut steel studs had a mean A-weighted equivalent continuous sound pressure level (LAeq) of 107.2 dB and a C-weighted peak sound pressure level (LCpeak) of 120.1 dB. Three of the saws-the chopsaw, the cut-off saw, and the grinder-had similar noise levels, whereas the cordless circular saw had higher noise levels. It took an average of 13.2 s to cut each stud, and workers in the study used power saws to cut steel studs for an average of 371.5 s per day. This average exposure time at the average recorded sound pressure levels (SPLs) suggests these saws can increase the risk of occupational noise-induced hearing loss, according to National Institute for Occupational Safety and Health (NIOSH) recommendations.

Nonpharmacological pain management approaches among U.S. construction workers: A cross-sectional pilot study.

U.S. construction workers experience high rates of injury that can lead to chronic pain. This pilot study examined nonpharmacological (without medication prescribed by healthcare provider) and pharmacological (e.g., prescription opioids) pain management approaches used by construction workers. A convenience sample of U.S. construction workers was surveyed, in partnership with the U.S. National Institute for Occupational Safety and Health (NIOSH) Construction Sector Program. Differences in familiarity and use of nonpharmacological and pharmacological pain management approaches, by demographics, were assessed using logistic regression models. A boosted regression tree model examined the most influential factors related to pharmacological pain management use, and potential reductions in use were counterfactually modeled. Of 166 (85%) of 195 participants reporting pain/discomfort in the last year, 72% reported using pharmacological pain management approaches, including 19% using opioids. There were significant differences in familiarity with nonpharmacological approaches by gender, education, work experience, and job title. Among 37 factors that predicted using pharmacological and non-pharmacological pain management approaches, training on the risks of opioids, job benefits for unpaid leave and paid disability, and familiarity with music therapy, meditation or mindful breathing, and body scans were among the most important predictors of potentially reducing use of pharmacological approaches. Providing these nonpharmacological approaches to workers could result in an estimated 23% (95% CI: 16%-30%) reduction in pharmacological pain management approaches. This pilot study suggests specific factors related to training, job benefits, and worker familiarity with nonpharmacological pain management approaches influence use of these approaches.

Association between exposure to metalworking fluid aerosols, occupational noise and chronic kidney disease: a cross-sectional study in China

BackgroundChronic kidney disease (CKD) carries a high public health burden yet little is known about the relationship between metalworking fluid (MWF) aerosols, occupational noise and CKD. We aimed to explore the relationship between occupational MWF aerosols, occupational noise and CKD.MethodsA total of 2,738 machinists were sampled from three machining companies in Wuxi, China, in 2022. We used the National Institute for Occupational Safety and Health (NIOSH) method 5524 to collect individual samples for MWF aerosols exposure, and the Chinese national standard (GBZ/T 189.8–2007) method to test individual occupational noise exposure. The diagnostic criteria for CKD were urinary albumin/creatinine ratio (UACR) of ≥ 30 mg/g and reduced renal function (eGFR < 60 mL.min− 1. 1.73 m− 2) lasting longer than 3 months. Smooth curve fitting was conducted to analyze the associations of MWF aerosols and occupational noise with CKD. A segmented regression model was used to analyze the threshold effects.ResultsWorkers exposed to MWF aerosols (odds ratio [OR] = 2.03, 95% confidence interval [CI]: 1.21–3.41) and occupational noise (OR = 1.77, 95%CI: 1.06–2.96) had higher prevalence of CKD than nonexposed workers. A nonlinear and positive association was found between increasing MWF aerosols and occupational noise dose and the risk of CKD. When daily cumulative exposure dose of MWF aerosols exceeded 8.03 mg/m3, the OR was 1.24 (95%CI: 1.03–1.58), and when occupational noise exceeded 87.22 dB(A), the OR was 1.16 (95%CI: 1.04–1.20). In the interactive analysis between MWF aerosols and occupational noise, the workers exposed to both MWF aerosols (cumulative exposure ≥ 8.03 mg/m3-day) and occupational noise (LEX,8 h ≥ 87.22 dB(A)) had an increased prevalence of CKD (OR = 2.71, 95%CI: 1.48–4.96). MWF aerosols and occupational noise had a positive interaction in prevalence of CKD.ConclusionsOccupational MWF aerosols and noise were positively and nonlinearly associated with CKD, and cumulative MWF aerosols and noise exposure showed a positive interaction with CKD. These findings emphasize the importance of assessing kidney function of workers exposed to MWF aerosols and occupational noise. Prospective and longitudinal cohort studies are necessary to elucidate the causality of these associations.

Cryogenic Modules for Synergistic O2 Generation and CO2 Retention in Closed-Circuit Escape Respirators

Since 2018, NASA and the National Institute for Occupational Safety and Health (NIOSH) have been developing a liquid oxygen storage module (LOXSM) based on the NASA patent-pending Cryogenic Flux Capacitor (CFC) technology. LOXSM’s could potentially replace the gaseous or chemical-based oxygen supply in current closed-circuit escape respirators (CCER), with reducing CCER size being a primary goal. By virtue of the CFC functionality, cryogenic oxygen stored within the LOXSM is released in response to heat input, ideally from the breathing loop. Prior efforts focused on the oxygen storage potential of silica aerogel materials that the CFC utilizes, and were previously reported. Current work explored the LOXSM’s potential to remove and retain CO2 produced by the CCER user, in conjunction with oxygen generation, creating a synergy that may be exploited to reduce or eliminate the chemical CO2 absorber used in current CCERs. A test program for determining CO2 retention is presented, as well as the evolution of LOXSM prototypes. Testing showed that it is possible to completely remove CO2 out of an effluent stream at the flowrate required for the capacity of the CCER for an appreciable time, and that the LOXSM prototype design progression had a positive effect on that duration.

Assessing Musculoskeletal Disorder Risks in an Automobile Part Manufacturing Factory: A Comparison Study of Biomechanical and Ergonomic Tools

Background: Various tools and methods are available to assess the risk of musculoskeletal injuries in occupational settings, each considering different assessment criteria. While these methods have been previously studied, further comparative investigations are still needed. Objectives: This study aimed to assess the risk of musculoskeletal disorders (MSDs) in workers performing various tasks using different ergonomic and biomechanical risk assessment tools and to compare the outcomes of these tools. Methods: This analytical and cross-sectional study was conducted in a sector of the SAIPA Automobile Part Manufacturing Factory in Iran. A total of 33 workers engaged in lifting, grinding, pushing, and lowering activities participated. Lifting activities involved handling parts weighing 36, 7.9, and 3.4 kg at three workstations. In total, six tasks were examined, and workers' discomfort levels were evaluated using the Cornell Musculoskeletal Discomfort Questionnaires (CMDQ). Fourteen biomechanical and ergonomic risk assessment tools were utilized and compared. Kendall's tau-b correlation coefficient and Cohen's kappa agreement coefficient were applied to determine relationships between different tools and to match the measurement of risk levels, respectively. Additionally, the mean and standard deviation of the data were calculated. Results: There was a high positive correlation between the outcomes of three biomechanical tools [3D static strength prediction programTM (3DSSPP), hand-calculation back compressive force (HCBCF), and JACK], with 3DSSPP and HCBCF being interchangeable for estimating lumbar spine loads. Ergonomic assessment tools showed a suitable correlation in assessing load-carrying tasks. Manual handling assessment charts (MAC) had perfect agreement with National Institute for Occupational Safety and Health (NIOSH), and SNOOK with Washington Industrial Safety and Health Act (WISHA). Among body posture evaluation methods, rapid upper limb assessment (RULA) and rapid entire body assessment (REBA) had the highest correlation. Lifting fatigue failure tool (LiFFT) correlated well with manual handling methods, and survival chance correlated better with body posture evaluation methods. Lowering activities were identified as the most hazardous. Conclusions: Ease of use and accuracy are key considerations when selecting biomechanical risk assessment tools. Experienced assessors can effectively utilize JACK, 3DSSPP, and HCBCF. The MAC and NIOSH, as well as RULA and REBA tools, are interchangeable. Selecting appropriate tools requires consideration of their limitations and advantages.

Modification of the Revised National Institute for Occupational Safety and Health (NIOSH) Lifting Equation to Determine the Individual Manual Lifting Risk in Malaysia's Manufacturing Industry.

The National Institute for Occupational Safety and Health (NIOSH) established the Revised NIOSH Lifting Equation (RNLE) for manual lifting risk assessment. The objectives of this study were to determine the characteristics of physical factors using the RNLE and to explore additional factors to RNLE by modifying it to an Individual Lifting Equation (ILE). This cross-sectional study was conducted in the manufacturing industry of three states in Malaysia among manual lifting workers. A questionnaire was administered, which comprised the sociodemographic characteristics and Nordic Musculoskeletal Questionnaire (NMQ) assessing low back pain (LBP). The RNLE dataset includes a load constant and six manual lifting variables collected from observational ergonomic risk assessment. The RNLE was modified to ILE by incorporating age, gender, and BMI. The equations' Lifting Index (LI) computed provides an overall manual lifting risk estimate. There were 165 participants, with a mean age of 28 years, and 108 (65.5%) were male. Most participants had a BMI within the normal range (60 (36.4%)) or were classified as overweight (54 (32.7%)). The lifting horizontal location showed the highest risk estimates, with the lowest meanmultiplier value of 0.55. In contrast, age and BMI had the lowest risk estimates, with mean multiplier values of 0.99 and 0.98, respectively. Among the participants, LI values of one or less, indicating very low risk, were observed in 58 (35.1%) for RNLE and 39 (23.6%) for ILE. Additionally, RNLE and ILE showed figures of 11 (6.7%) and 20 (12.1%), respectively, signifying a very high risk of LI exceeding three. Studying the lifting factors and equation multipliers from RNLE is critical for evaluating the risk estimates of manual lifting. Exploring the ILE based on individual characteristics is appropriate to support the ergonomic program. Further study is needed to validate the ILE as an accurate screening tool for determining LBP risk estimates.

Real-time risk assessment of multi-parameter induced fall accidents at construction sites

In this research, a risk assessment model was developed that concurrently considers the location and physiological risk factors for fall accidents in workers at construction sites. In terms of location risk, data on 1683 occupational fall accidents involving 1718 worker casualties in the construction industry were collected for the period 1996–2016 from the Institute of Labor, Occupational Safety and Health (ILOSH), Taiwan. Next, the locations of these fall accidents were identified and defined as hazardous areas, with each area assigned a fall-risk level based on the average number of occupational accidents per year. In terms of physiological risk, the thermal hazard evaluation model, Recommended Alert Limits/Recommended Exposure Limits (RALs/RELs), developed by the National Institute for Occupational Safety and Health (NIOSH), USA was used in this study. This model uses metabolic heat and wet bulb globe temperature (WBGT) to recommend hourly rest/work times for workers. Using WBGT and one hour as the basic unit of time, varying degrees of metabolic heat, defined as metabolic heat loading severity (MHLS), were obtained. An optical heart rate (HR) sensor was applied in this study to measure HR, which was subsequently converted to a metabolic heat value using the Malchaire J metabolic heat evaluation model. Next, metabolic heat loading risk level was evaluated based on the MHLS. Finally, the location-based fall-risk level was multiplied by the MHLS, generating a risk evaluation model for fall accidents. The evaluation results identify the real-time fall-risk level of each worker and, if needed, suggest actions to be taken to mitigate the elevated risks of fall accidents identified by the model.

Statistical estimation of noise induced hearing loss among the drivers in one of the most polluted cities of India

In the present study, an attempt has been made to assess the impact of vehicular noise upon the 3-wheeler tempo drivers and to know whether there is any relationship between hearing loss and cumulative noise exposure. For this purpose, 3-wheeler tempo drivers (Exposed group) and non-commercial light motor vehicle car drivers (Unexposed group) were chosen as study subjects. Three traffic routes were selected to assess the noise level during waiting and running time in the exposed and unexposed groups. Among all three routes, the highest mean noise level (Leq) was observed on the Chowk to Dubagga route for waiting and en-route noise measurement. It was measured as 84.13 dB(A) and 86.36 dB(A) for waiting and en-route periods of 7.68 ± 3.46 and 31.05 ± 6.6 min, respectively. Cumulative noise exposure was found to be significantly different (p < 0.001) in all age groups of exposed and unexposed drivers. Audiometric tests have been performed over both exposed and unexposed groups. The regression analysis has been done keeping hearing loss among tempo drivers as the dependent variable and age (years) and Energy (Pa2 Hrs) as the independent variable using three different criteria of hearing loss definitions, i.e., World Health Organization, National Institute for Occupational Safety and Health (NIOSH), Occupational Safety and Health Administration criteria. Among these three criteria, the NIOSH criterion of hearing loss best explained the independent variables. It could explain the total variation in dependent variable by independent variable quite well, i.e., 68.1%. The finding showed a linear relationship between cumulative noise exposures (Pa2 Hrs) and the exposed group's hearing loss (dB), i.e., hearing loss increases with increasing noise dose. Based on the findings, two model equations were developed to identify the safe and unsafe noise levels with exposure time.

Evaluation of a non-dispersive infrared spectrometer for quantifying organic and elemental carbon in diesel particulate matter.

Diesel particulate matter (DPM) is a common and well-known health hazard in the mining environment. The regulatory method for monitoring both the organic and elemental carbon (OC, EC) portions of DPM is a laboratory-based thermal-optical method with a typical turnaround time of one week. In order to evaluate exposure levels and take corrective action prior to overexposure, a portable real-time device capable of quantifying both OC and EC is needed. To that end, researchers from the National Institute for Occupational Safety and Health (NIOSH) designed and tested the feasibility of a device based on bandpass optical filters that target key infrared wavelengths associated with DPM and its spectroscopic baseline. The resulting device, referred to here as a non-dispersive infrared (NDIR) spectrometer could serve as the basis of a cost-effective, field-portable alternative to the laboratory thermal-optical method. The limits of quantification (LOD) indicate that the NDIR spectrometer can quantify EC, OC, and TC provided they are present at 20, 37, and 46 μg/m3 or more, respectively. In the event that the NDIR spectrometer is integrated with a sampler and filter tape the LOD is estimated to be reduced to 13, 7, and 10 μg/m3 for EC, OC, and TC, respectively. These LOD estimates assume a face velocity of 59 cm/s and a sampling time of 30 min.

Health risk assessment of exposure to benzene, toluene, ethylbenzene and xylenes in a vehicle manufacturing industry in Iran

IntroductionConsidering the adverse carcinogenic and non-carcinogenic health effects of Volatile Organic Compounds (VOC) and specially Benzene, Toluene, Ethylbenzene and Xylenes (BTEX) which are widely used in vehicle manufacturing industry, it is clear that monitoring and control of occupational exposure to these substances is of utmost significance. More often than not the studies on occupational exposure to VOCs in vehicle manufacturing industry—specifically BTEX—have been carried out exclusively in paint shop units. The purpose of this study was to assess occupational BTEX exposure & health risk in different units of a vehicle manufacturing industry.Material and methodsFoam injection unit (FIU), gluing unit (GU), repair shop unit (RSU), molding unit (MU) as well as paint shop units (PSU) were selected for this study. Sampling and analysis were conducted based on National Institute for Occupational Safety and Health (NIOSH) 1501 guidelines by utilizing MSA personal sampling pumps set to 0.2 l/m and Gas Chromatography equipped with Flame Ionization Detector (GC-FID). Risk characterization and assessment was performed using Environmental Protection Agency Risk Assessment Information System (EPA RAIS).Results and conclusionThe results revealed that the concentration of benzene in gluing and paint shop units was above occupational exposure limits. Carcinogenic risk levels in 8 out of 10 units registered in the 1E-2 to 1E-4 range, and only two units registered a risk level below EPA’s acceptable risk level (10–6). The highest risk levels were measured in gluing, paint shop and repair shop units. Furthermore, the total non-carcinogenic hazard quotient was measured higher than 1 in 8 out of 10 studied units. Considering the abundance and wide use of VOCs -most notably BTEX- and the adverse carcinogenic and non-carcinogenic health effects of these compounds, it is advised to: change the type of paint used in paint shops, improve the existing ventilation systems, develop new and more efficient ventilation systems and conduct consistent training.