Temperature impact on monochloramine, free ammonia, and free chlorine indophenol methods.

A commercial colorimetric indophenol (IP) method is used for determining monochloramine (NH2Cl) concentrations for process control in chloraminated public water systems and chloramine-related research. The NH2Cl - IP method excludes some quality control procedures typically included in drinking water methods and is not approved by the United States Environmental Protection Agency (U.S. EPA) for compliance monitoring. Therefore, the authors developed and validated a more complete NH2Cl-IP method, building on the commercial technique, as a candidate for future approval. During method development, temperature impact on color development was investigated. Color development time increased as temperature decreased. Below 20 °C, times needed for full color development were greater than those reported in the commercial method, reaching nearly three times longer at 5 °C. This observed temperature dependence also applies to free ammonia and free chlorine indophenol methods. To avoid measurement errors of samples analyzed below 20 °C, use of reaction times determined in this study is recommended for these indophenol methods.

Laser-Deposited Carbon Aerogel Derived from Graphene Oxide Enables NO2-Selective Parts-per-Billion Sensing.

Laser-deposited carbon aerogel is a low-density porous network of carbon clusters synthesized using a laser process. A one-step synthesis, involving deposition and annealing, results in the formation of a thin porous conductive film which can be applied as a chemiresistor. This material is sensitive to NO2 compared to ammonia and other volatile organic compounds and is able to detect ultra-low concentrations down to at least 10 parts-per-billion. The sensing mechanism, based on the solubility of NO2 in the water layer adsorbed on the aerogel, increases the usability of the sensor in practically relevant ambient environments. A heating step, achieved in tandem with a microheater, allows the recovery to the baseline, making it operable in real world environments. This, in combination with its low cost and scalable production, makes it promising for Internet-of-Things air quality monitoring.

Blended Simulation Progress Testing for Assessment of Practice Readiness.

Objective. To design an assessment of practice readiness using blended-simulation progress testing. Design. A five-station, blended simulation assessment was developed to evaluate patient care outcomes in first- and third-year pharmacy (P1 and P3) students, as well as first-year postgraduate (PGY1) pharmacy residents. This assessment of practice readiness included knowledge and performance evaluations administered as a progress test. Assessment. Eighteen PGY1 residents, 108 P3 students, and 106 P1 students completed the assessment. P3 students scored significantly higher than P1 students across all evaluations. Third-year pharmacy students scored significantly lower than PGY1 residents in interprofessional communications and attitudes of ownership in a standardized colleague/mannequin model station, and in patient communication in a standardized patient station. Conclusion. Learners demonstrated evolving skills as they progressed through the curriculum. A blended simulation integrated progress test provides data for improvement of individual student clinical skills, informs curricular advancement, and aligns curricular content, process, and outcomes with accreditation standards.

Development and Evaluation of Ergonomic Interventions for Bucket Handling on Farms.

OBJECTIVE: The aim of this study was to introduce and evaluate two interventions, Ergo Bucket Carrier (EBC) and Easy Lift (EL), for youths (and adults) to handle water/feed buckets on farms. BACKGROUND: The physical activities of both adult and youth farm workers contribute to the development of low-back disorders (LBDs). Many of the activities youths perform on farms are associated with increased LBD risk, particularly, the handling of water and feed buckets. METHOD: Seventeen adult and youth participants (10 males and seven females) participated in this study. To assess the risk of LBDs, the participants were instrumented with a three-dimensional spinal electrogonio-meter while lifting, carrying, and dumping water buckets using the traditional method and the two interventions. RESULTS: For both the adult and youth groups, the results showed that the two interventions significantly decrease the magnitudes of LBD risk in many of the tasks evaluated. Overall, the use of the EBC resulted in a 41% reduction in the level of LBD risk for the carrying task and a reduction of 69% for the dumping task. Using the EL, on the other hand, is especially effective for lifting tasks (55% reduction in LBD risk). Results of the subjective response were consistent with the objective evaluations. CONCLUSION: This study demonstrated the potential for ergonomic interventions in reducing LBD risk during the common farming task of bucket handling. APPLICATION: Potential application of this study includes the introduction of the EBC and EL in family farms to reduce the LBD risk among youth and adult farmers.

Variable Lifting Index (VLI): A New Method for Evaluating Variable Lifting Tasks.

OBJECTIVE: We seek to develop a new approach for analyzing the physical demands of highly variable lifting tasks through an adaptation of the Revised NIOSH (National Institute for Occupational Safety and Health) Lifting Equation (RNLE) into a Variable Lifting Index (VLI). BACKGROUND: There are many jobs that contain individual lifts that vary from lift to lift due to the task requirements. The NIOSH Lifting Equation is not suitable in its present form to analyze variable lifting tasks. METHOD: In extending the prior work on the VLI, two procedures are presented to allow users to analyze variable lifting tasks. One approach involves the sampling of lifting tasks performed by a worker over a shift and the calculation of the Frequency Independent Lift Index (FILI) for each sampled lift and the aggregation of the FILI values into six categories. The Composite Lift Index (CLI) equation is used with lifting index (LI) category frequency data to calculate the VLI. The second approach employs a detailed systematic collection of lifting task data from production and/or organizational sources. The data are organized into simplified task parameter categories and further aggregated into six FILI categories, which also use the CLI equation to calculate the VLI. RESULTS: The two procedures will allow practitioners to systematically employ the VLI method to a variety of work situations where highly variable lifting tasks are performed. CONCLUSIONS: The scientific basis for the VLI procedure is similar to that for the CLI originally presented by NIOSH; however, the VLI method remains to be validated. APPLICATION: The VLI method allows an analyst to assess highly variable manual lifting jobs in which the task characteristics vary from lift to lift during a shift.

Development of Human Posture Simulation Method for Assessing Posture Angles and Spinal Loads.

Video-based posture analysis employing a biomechanical model is gaining a growing popularity for ergonomic assessments. A human posture simulation method of estimating multiple body postural angles and spinal loads from a video record was developed to expedite ergonomic assessments. The method was evaluated by a repeated measures study design with three trunk flexion levels, two lift asymmetry levels, three viewing angles and three trial repetitions as experimental factors. The study comprised two phases evaluating the accuracy of simulating self and other people's lifting posture via a proxy of a computer-generated humanoid. The mean values of the accuracy of simulating self and humanoid postures were 12° and 15°, respectively. The repeatability of the method for the same lifting condition was excellent (~2°). The least simulation error was associated with side viewing angle. The estimated back compressive force and moment, calculated by a three dimensional biomechanical model, exhibited a range of 5% underestimation. The posture simulation method enables researchers to simultaneously quantify body posture angles and spinal loading variables with accuracy and precision comparable to on-screen posture matching methods.

Evidence of health risks associated with prolonged standing at work and intervention effectiveness.

PURPOSE: Prolonged standing at work has been shown to be associated with a number of potentially serious health outcomes, such as lower back and leg pain, cardiovascular problems, fatigue, discomfort, and pregnancy-related health outcomes. Recent studies have been conducted examining the relationship between these health outcomes and the amount of time spent standing while on the job. The purpose of this article was to provide a review of the health risks and interventions for workers and employers that are involved in occupations requiring prolonged standing. A brief review of recommendations by governmental and professional organizations for hours of prolonged standing is also included. FINDINGS: Based on our review of the literature, there seems to be ample evidence showing that prolonged standing at work leads to adverse health outcomes. Review of the literature also supports the conclusion that certain interventions are effective in reducing the hazards associated with prolonged standing. Suggested interventions include the use of floor mats, sit-stand workstations/chairs, shoes, shoe inserts and hosiery or stockings. Studies could be improved by using more precise definitions of prolonged standing (e.g., duration, movement restrictions, and type of work), better measurement of the health outcomes, and more rigorous study protocols. CONCLUSION AND CLINICAL RELEVANCE: Use of interventions and following suggested guidelines on hours of standing from governmental and professional organizations should reduce the health risks from prolonged standing.

Reduction of spinal loads through adjustable interventions at the origin and destination of palletizing tasks.

OBJECTIVE: This article evaluates the effectiveness of two interventions: a self-leveling pallet carousel designed to position the loads vertically and horizontally at origin, and an adjustable cart designed to raise loads vertically at destination to reduce spine loads. BACKGROUND: Low back disorders among workers in manual material handling industries are very prevalent and have been linked to manual palletizing operations. Evidence into the effectiveness of ergonomic interventions is limited, with no research that investigates interventions with adjustable load location. METHOD: Thirteen males experienced in manual material handling participated in simulated order selecting tasks where spine loads were quantified for each intervention condition: carousel to traditional cart, pallet to traditional cart, pallet to adjustable cart, and carousel to adjustable cart. RESULTS: The results showed that combining both devices results in reduction in spine compression (61%), anterior-posterior shear (72%), and lateral shear (63%) compared to traditional palletizing conditions. Individually, the carousel was responsible for the greatest reductions, but the lowest values were typically achieved by combining the adjustable cart and carousel. CONCLUSION: The combination of the interventions (self-leveling carousel and adjustable cart) was most effective in reducing the spine loads when compared to the traditional pallet-cart condition. The individual interventions also reduced the loads compared to the traditional condition. APPLICATION: With de-palletizing/palletizing tasks being a major source of low back injuries, the combination of self-leveling carousel and adjustable cart has been found to be effective in reducing the peak spine loading as compared to traditional pallet on floor and nonadjustable flat cart conditions.

Efficacy of the revised NIOSH lifting equation to predict risk of low-back pain associated with manual lifting: a one-year prospective study.

OBJECTIVE: The objective was to evaluate the efficacy of the Revised National Institute for Occupational Safety and Health (NIOSH) lifting equation (RNLE) to predict risk of low-back pain (LBP). BACKGROUND: In 1993, NIOSH published the RNLE as a risk assessment method for LBP associated with manual lifting. To date, there has been little research evaluating the RNLE as a predictor of the risk of LBP using a prospective design. METHODS: A total of 78 healthy industrial workers' baseline LBP risk exposures and self-reported LBP at one-year follow-up were investigated. The composite lifting index (CLI), the outcome measure of the RNLE for analyzing multiple lifting tasks, was used as the main risk predictor. The risk was estimated using the mean and maximum CLI variables at baseline and self-reported LBP during the follow-up. Odds ratios (ORs) were calculated using a logistic regression analysis adjusted for covariates that included personal factors, physical activities outside of work, job factors, and work-related psychosocial characteristics. RESULTS: The one-year self-reported LBP incidence was 32.1%. After controlling for history of prior LBP, supervisory support, and job strain, the categorical mean and maximum CLI above 2 had a significant relationship (OR = 5.1-6.5) with self-reported LBP, as compared with the CLI below or equal to I. The correlation between the continuous CLI variables and LBP was unclear. CONCLUSIONS: The CLI > 2 threshold may be useful for predicting self-reported LBP. Research with a larger sample size is needed to clarify the exposure-response relationship between the CLI and LBP.

Provisional recommended weight limits for manual lifting during pregnancy.

OBJECTIVE: The National Institute for Occupational Safety and Health (NIOSH) Revised Lifting Equation (RNLE) was adapted to derive recommended weight limits (RWLs) for pregnant workers and to develop corresponding guidelines for clinicians. BACKGROUND: In the past three decades there has been a large increase in the number of women employed outside the home and remaining in the workforce during pregnancy. Practical authoritative guidelines based on accumulated evidence are needed to inform allowable work activity levels for healthy pregnant workers. METHOD: Empirically based lifting criteria established by NIOSH to reduce the risk of overexertion injuries in the general U.S. working population were evaluated for application to pregnant workers. Our evaluation included an extensive review of the literature linking occupational lifting to maternal and fetal health. Decision logic and supporting literature are presented, along with computational details. RESULTS: Provisional RWLs for pregnant workers were derived from the RNLE, along with guidelines for clinicians. The guidelines advise against pregnant workers lifting below midshin and overhead. CONCLUSION: Based on our review of the available evidence, we present lifting thresholds that most pregnant workers with uncomplicated pregnancies should be able to perform without increased risk of adverse maternal and fetal health consequences. Except for restrictions involving lifting from the floor and overhead, the provisional guidelines presented are compatible with NIOSH lifting recommendations adopted in the early 1990s for the general working population. APPLICATION: Implementation of these provisional guidelines could protect millions of female workers in the workplace from fetal and maternal lifting-related health problems.

Psychophysical basis for maximum pushing and pulling forces: A review and recommendations.

The objective of this paper was to perform a comprehensive review of psychophysically determined maximum acceptable pushing and pulling forces. Factors affecting pushing and pulling forces are identified and discussed. Recent studies show a significant decrease (compared to previous studies) in maximum acceptable forces for males but not for females when pushing and pulling on a treadmill. A comparison of pushing and pulling forces measured using a high inertia cart with those measured on a treadmill shows that the pushing and pulling forces using high inertia cart are higher for males but are about the same for females. It is concluded that the recommendations of Snook and Ciriello (1991) for pushing and pulling forces are still valid and provide reasonable recommendations for ergonomics practitioners. Regression equations as a function of handle height, frequency of exertion and pushing/pulling distance are provided to estimate maximum initial and sustained forces for pushing and pulling acceptable to 75% male and female workers. At present it is not clear whether pushing or pulling should be favored. Similarly, it is not clear what handle heights would be optimal for pushing and pulling. Epidemiological studies are needed to determine relationships between psychophysically determined maximum acceptable pushing and pulling forces and risk of musculoskeletal injuries, in particular to low back and shoulders.

Clinical guidelines for occupational lifting in pregnancy: evidence summary and provisional recommendations.

Empirically based lifting criteria established by the National Institute for Occupational Safety and Health (NIOSH) to reduce the risk of overexertion injuries in the general US working population were evaluated for application to pregnant workers. This report proposes criteria to guide decisions by medical providers about permissible weights for lifting tasks performed at work over the course of an uncomplicated pregnancy. Our evaluation included an extensive review of the literature linking occupational lifting to maternal and fetal health. Although it has been 29 years since the American Medical Association's Council on Scientific Affairs published its report on the Effects of Pregnancy on Work Performance, these guidelines continue to influence clinical decisions and workplace policies. Provisional clinical guidelines derived from the NIOSH lifting criteria that account for recent evidence for maternal and fetal health are presented and aim to improve the standard of care for pregnant workers.

Ergonomic Assessment of Floor-based and Overhead Lifts.

Manual full-body vertical lifts of patients have high risk for developing musculoskeletal disorders. Two primary types of battery-powered lift assist devices are available for these tasks: floor-based and overhead-mounted devices. Studies suggest that the operation of floor-based devices may require excessive pushing and pulling forces and that overhead-mounted devices are safer and require lower operating forces. This study evaluated required operating hand forces and resulting biomechanical spinal loading for overhead-mounted lifts versus floor-based lifts across various floor surfaces and patient weight conditions. We did not examine differences in how operators performed the tasks, but rather focused on differences in required operating forces and estimated biomechanical loads across various exposure conditions for a typical operator. Findings show that the floor-based lifts exceeded recommended exposure limits for pushing and pulling for many of the floor/weight conditions and that the overhead-mounted lifts did not. As expected, forces and spinal loads were greater for nonlinoleum floor surfaces compared with linoleum floors. Based on these findings, it is suggested that overhead-mounted devices be used whenever possible, particularly in instances where carpeted floors would be encountered.

AORN ergonomic tool 7: pushing, pulling, and moving equipment on wheels.

Pushing and pulling equipment in and around the OR can place high shear force demands on perioperative team members' shoulder and back muscles and joints. These high forces may lead to work-related musculoskeletal disorders. AORN Ergonomic Tool 7: Pushing, Pulling, and Moving Equipment on Wheels can help perioperative team members assess the risk of pushing and pulling tasks in the perioperative setting. The tool provides evidence-based suggestions about when assistive devices should be used for these tasks and is based on current ergonomic safety concepts, scientific evidence, and knowledge of effective technology and procedures, including equipment and devices for safe patient handling.

Efficacy of the revised NIOSH lifting equation to predict risk of low back pain due to manual lifting: expanded cross-sectional analysis.

OBJECTIVE: To evaluate whether the Revised NIOSH Lifting Equation (RNLE) is a valid tool for assessing risk of low back pain (LBP) due to manual lifting by using combined data from two cross-sectional studies of 1-year prevalence. METHODS: Results from a symptom and occupational history questionnaire and RNLE analysis for 677 subjects employed in 125 manual lifting jobs at nine industrial sites were combined from two studies. RESULTS: The odds of LBP increased as the lifting index (LI) increased from 1.0 to 3.0. A statistically significant odds ratio (OR) was found for both the 1 < LI ≤ 2 (OR = 1.81) and the 2 < LI ≤ 3 categories (OR = 2.26). For jobs with an LI value greater than 3.0, however, the OR remained nonsignificant. The 2 < LI ≤ 3 group remained statistically significant after adjusting for age, gender, body mass index, and psychosocial factors. CONCLUSIONS: It is clear that as the LI increases, the risk of LBP increases. Longitudinal studies are needed.

AORN Ergonomic Tool 6: lifting and carrying supplies and equipment in the perioperative setting.

Perioperative team members often are required to lift and carry heavy supplies and equipment into and around the OR; this includes lifting equipment such as hand tables, fluoroscopy boards, stirrups, Wilson frames, irrigation containers for lithotripsy, and heavy instrument pans. Lifting heavy objects creates considerable risk for musculoskeletal injuries to the back and shoulders. AORN Ergonomic Tool 6: Lifting and Carrying Supplies and Equipment in the Perioperative Setting can help caregivers evaluate lifting and carrying tasks and take measures to protect themselves from injury. Caregivers can use the revised National Institute for Occupational Safety and Health lifting equation to assess whether a specific lifting task can be performed safely.

AORN Ergonomic Tool 3: lifting and holding the patient's legs, arms, and head while prepping.

Lifting the arms, legs, or head of a patient while prepping these areas for surgery can exert strong forces on the muscles and joints of the shoulders and backs of perioperative team members who perform this task, which may lead to work-related musculoskeletal disorders. AORN Ergonomic Tool 3: Lifting and Holding the Patient's Legs, Arms, and Head While Prepping provides scientifically based determinations of the amount of weight perioperative personnel can safely lift and hold manually for up to one, two, and three minutes using one hand or both. If these weight limits are exceeded, additional staff members or assistive devices are needed to help with the task.

AORN ergonomic tool 2: positioning and repositioning the supine patient on the OR bed.

Positioning or repositioning a patient on the OR bed in preparation for a surgical procedure presents a high risk for musculoskeletal disorders, such as low-back and shoulder injuries, for perioperative personnel. Safe patient handling requires knowledge of current ergonomic safety concepts, scientific evidence, and equipment and devices to ensure that neither the patient nor the caregiver is at risk for injury. AORN Ergonomic Tool 2: Positioning and Repositioning the Supine Patient on the OR Bed provides guidelines that enable perioperative personnel to determine safe methods for positioning and repositioning a patient in the semi-Fowler, lateral, or lithotomy position in preparation for surgery.