8-hour Work Shift Research Articles

A Machine Learning and Optimization Framework for Efficient Alert Management in a Cybersecurity Operations Center

Cybersecurity operations centers (CSOCs) protect organizations by monitoring network traffic and detecting suspicious activities in the form of alerts. The security response team within CSOCs is responsible for investigating and mitigating alerts. However, an imbalance between alert volume and available analysts creates a backlog, putting the network at risk of exploitation. Recent research has focused on improving the alert-management process by triaging alerts, optimizing analyst scheduling, and reducing analyst workload through systematic discarding of alerts. However, these works overlook the delays caused in alert investigations by several factors, including: (i) false or benign alerts contributing to the backlog; (ii) analysts experiencing cognitive burden from repeatedly reviewing unrelated alerts; and (iii) analysts being assigned to alerts that do not match well with their expertise. We propose a novel framework that considers these factors and utilizes machine learning and mathematical optimization methods to dynamically improve throughput during work shifts. The framework achieves efficiency by automating the identification and removal of a portion of benign alerts, forming clusters of similar alerts, and assigning analysts to alerts with matching attributes. Experiments conducted using real-world CSOC data demonstrate a 60.16% reduction in the alert backlog for an 8-h work shift compared to currently employed approach.

Encounter patterns and worker absenteeism/presenteeism among healthcare providers in Thailand

• We examined number of encounters made by healthcare providers in inpatient wards. • Wards were stratified by risk of respiratory virus transmission. • A median encounter duration was two minutes. Difference in encounter patterns by ward type was observed. • About one in five work shifts were staffed by HCPs with acute muscle pain and/or respiratory symptoms who continued to work while ill. • The encounter episodes were highest among physicians working working during the 8-hour evening shift in high-risk wards. We examined the characteristics of healthcare providers’ (HCPs) encounters, and the frequency of worker absenteeism/presenteeism, among HCPs in inpatient wards at a tertiary-level public hospital in Bangkok, Thailand. The wards were stratified by risk of respiratory virus transmission: low-risk (Surgery, Rehabilitation, Orthopedic, and Obstetrics and Gynecology) and high-risk (Medicine, Pediatric, Emergency, and Ear, Nose, and Throat) . Observers followed HCPs throughout one self-selected 8-hour work shift to record their interaction with others. An encounter was defined as a 2-way conversation with ≥3 words in the physical presence of ≥1 person at <3 feet distance; or a physical skin-to-skin touch. We administered structured questionnaires to document demographics, health and work history, past practice while ill, and recent and current acute muscle pain and/or respiratory symptoms. We collected data from time and attendance records of participants reporting illness within the past seven days. From July to August 2019, 240 HCPs were enrolled and observed during 395 work shifts; 15,878 total encounters were made with a median duration of two minutes (interquartile range, 1–3). Number of contacts ranged from 25 to 49 encounters/8 h in the low-risk wards and 40 to 66 encounters/8 h in the high-risk wards. Physicians working during the 8-hour evening shift in high-risk wards had the highest estimated number of contacts (66 encounters; 95% confidence interval [CI], 43–89) while nurses working during the 8-hour night shift in the low-risk wards had the lowest number of contacts (25 encounters; 95% CI, 22–28). Forty-two (11%) shifts were staffed by HCPs with acute muscle pain and/or respiratory symptom(s) at the time of interview, and 89 (23%) by HCPs who reported symptom(s) during the past seven days, for which none were absent from work. We observed difference in encounter patterns by ward type. About one in five work shifts were staffed by HCPs with acute muscle pain and/or respiratory symptoms who continued to work while ill. These findings have implications for preventing infectious disease transmission and the policy around sick leave in healthcare settings.

Hearing Protection Devices Use and Its Relationship with Hearing Loss among Steel Industry Workers of Samut Prakan Province, Thailand

Objective: To investigate hearing protection devices (HPDs) use and its relationship with hearing loss among steel industry workers in Thailand. Materials and Methods: The present cross-sectional study included 93 eligible participants who are working in the designated high-noise-level zones, which is 85 or more A-weighted decibels [dB(A)] for eight hours time-weighted average, of the two factories. Self-report forms were used to obtain HPDs use by industry workers and noise exposure level was measured with Spark® (Model 706) noise dosimeter. Audiometric screening for hearing loss was performed at a regional hospital by the qualified technician. The hearing loss in each ear was defined if the average threshold level was found to have exceeded 25 dB(A) at high frequencies of 4 and 6 kHz. Results: The findings showed that 45.2% of workers used earplug, 16.1% used earmuff, and 38.7% used both, and most workers (55.8%) wear HDPs regularly, for six of seven days per week. Fifty seven percent of workers wear HDPs for more than 60% time of an 8-hour work shift. Most workers (75.2%) have hearing loss. Conclusion: The authors’ result revealed that almost half of workers used hearing protection devices and most workers use HPDs during the 8-hour work time. Abnormal hearing ability were found among workers. The education program such as the hazards of noise on potential auditory loss, a noise education training program and full use of HPDs are encouraged to prevent effect of noise on workers. Keywords: Hearing protection devices, Noise induced hearing loss, Steel industry

Monitoring and Assessment of Airborne Respirable Limestone Dust and Free Silica Content in an Indian Mine.

Background.Dust exposure and its related harmful effects on miners is a serious health issue.Objectives.The present study was undertaken to identify respirable dust concentrations and free silica content in 24 dust samples collected from a limestone mine during pre-monsoon and post-monsoon seasons.Methods.Time-weighted average (TWA) dust concentrations were calculated for 8-hour work shifts followed by determination of free silica concentration using the Fourier transform infrared spectroscopy technique.Results.The TWA dust concentration for personal and area dust samples during September 2013 was found to be in the range of 0.32–1.04 mg/m3 and 0.25–0.54 mg/m3, respectively. For February 2014, the TWA dust concentration was between 0.62–1.23 mg/m3 for personal samples and 1.04–2.64 mg/m3 for area samples. Samples collected in February 2014 had marginally higher values of dust levels in the air of the mine compared to September 2013. The highest dust concentration was found to be 1.23 mg/m3 for a drill operator and 2.64 mg/m3 at the crusher belt conveyor junction. The average free silica percent for the samples collected in February 2014 was 1.73%, which was almost double compared to September 2013 (0.87%).Conclusions.In both seasons, personal dust samples had higher free silica content than area dust samples. Even though dust concentrations were below the permissible limit, workers had widely different exposures, hence many of them may be at risk of pneumoconiosis when exposure is prolonged.Participant Consent.ObtainedCompeting Interests.The authors declare no competing financial interests.

The workload of heavy workers is associated with increased low-grade inflammation, emotional and oxidative stress

Background There is limited knowledge with regard to oxidative stress in different working categories e.g. between heavy workers and desktop workers. Therefore, the aim of this study was to evaluate the antioxidative as well as oxidative stress profile exactly in these occupational groups. Methods We enrolled 79 male subjects i.e. 27 employees as desktop workers (age 38.8 ± 9.1) and 52 heavy workers in a slaughterhouse (age 40.8 ± 8.2). Blood was drawn in the morning after an 8-hour work shift from an antecubital vein. Total antioxidant capacity (TAC), uric acid, total polyphenols (PPm) and endogenous peroxidase-activity (EPA) were determined to evaluate the antioxidative potential while total peroxides (TOC), malondialdehyde (MDA), myeloperoxidase (MPO), were used as oxidative stress biomarkers. In addition, we analysed adrenocorticotropic hormone (ACTH), hsCRP and interleukin-6 (IL-6) and the brain-derived neurotrophic factor (BDNF) as biomarkers for inflammation and emotional stress. Results These two working groups show significant differences between BMI (p=0.0026). Furthermore, we observed significant increased concentrations for TOC (p Conclusion These results indicate a distinct association between occupational category and prevalence for oxidative stress. Desktop workers were at an advantage over heavy workers for each biomarker indicating a stress situation except for the total antioxidant status. It is a fact that uric acid is an excellent antioxidant and becomes increased during oxidative stress. Thus, we determined uric acid and observed a high correlation to TAC, which is an explanation for this paradox – in spite of the fact, that there was no significant difference for uric acid concentrations between both groups. Although classical biomarkers as MDA, MPO or IL-6 were insensitive to indicate differences in these two working groups, we still achieved significant differences with sensitive and high-throughput methods to the disadvantage for heavy workers, disclosing the linkage between low-grade inflammation emotional and oxidative stress. Further studies are needed to verify these preliminary results and to complement different working groups.

Reorganizing Care With the Implementation of Electronic Medical Records: A Time-Motion Study in the PICU.

To assess caregivers' patient care time before and after the implementation of a reorganization of care plan with electronic medical records. A prospective, observational, time-motion study. A level 3 PICU. Nurses and orderlies caring for intubated patients during an 8-hour work shift before (2008-2009) and after (2016) implementation of reorganization of care in 2013. The reorganization plan included improved telecommunication for healthcare workers, increased tasks delegated to orderlies, and an ICU-specific electronic medical record (Intellispace Critical Care and Anesthesia information system, Philips Healthcare). Time spent completing various work tasks was recorded by direct observation, and proportion of time in tasks was compared for each study period. A total of 153.7 hours was observed from 22 nurses and 14 orderlies. There was no significant difference in the proportion of nursing patient care time before (68.8% [interquartile range, 48-72%]) and after (55% [interquartile range, 51-57%]) (p = 0.11) the reorganization with electronic medical record. Direct patient care task time for nurses was increased from 27.0% (interquartile range, 30-37%) before to 34.7% (interquartile range, 33-75%) (p = 0.336) after, and indirect patient care tasks decreased from 33.6% (interquartile range, 23-41%) to 18.6% (interquartile range, 16-22%) (p = 0.036). Documentation time significantly increased from 14.5% (interquartile range, 12-22%) to 26.2% (interquartile range, 23-28%) (p = 0.032). Nursing productivity ratio improved from 28.3 to 26.0. A survey revealed that nursing staff was satisfied with the electronic medical record, although there was a concern for the maintenance of oral communication in the unit. The reorganization of care with the implementation of an ICU-specific electronic medical record in the PICU did not change total patient care provided but improved nursing productivity, resulting in improved efficiency. Documentation time was significantly increased, and concern over reduced oral communication arose, which should be a focus for future electronic improvement strategies.

Work Intensity, Low-Grade Inflammation, and Oxidative Status: A Comparison between Office and Slaughterhouse Workers.

Limited knowledge exists about the impact of physical workload on oxidative stress in different occupational categories. Thus, we aimed to investigate the oxidative and inflammatory status in employees with different physical workloads. We enrolled a total of 79 male subjects, 27 office workers (mean age 38.8 ± 9.1 years) and 52 heavy workers, in a slaughterhouse (mean age 40.8 ± 8.2 years). Fasting blood was drawn from an antecubital vein in the morning of the midweek before an 8-hour or 12-hour work shift. The antioxidative capacity was assessed measuring total antioxidant capacity (TAC), uric acid, total polyphenols (PPm), and endogenous peroxidase activity (EPA). Total peroxides (TOC), malondialdehyde (MDA), and myeloperoxidase (MPO) were analyzed as prooxidative biomarkers, and an oxidative stress index (OSI) was calculated. In addition, hsCRP, interleukin-6 (IL-6), MDA-LDL IgM antibodies, galectin-3, adrenocorticotropic hormone (ACTH), and the brain-derived neurotrophic factor (BDNF) were measured as biomarkers of chronic systemic inflammation and emotional stress. TOC (p = 0.032), TAC (p < 0.001), ACTH (p < 0.001), OSI (p = 0.011), and hsCRP (p = 0.019) were significantly increased in the heavy workers group, while EPA, BDNF (p < 0.001), and polyphenols (p = 0.004) were significantly higher in office workers. Comparison between 8 and 12 h shifts showed a worse psychological condition in heavy workers with increased levels for hsCRP (p = 0.001) and reduced concentration of BDNF (p = 0.012) compared to office workers. Oxidative stress and inflammation are induced in heavy workers and are particularly pronounced during long working hours, that is, 12-hour versus 8-hour shifts.

Fitbit Activity Trackers Interrupt Workplace Sedentary Behavior: A New Application.

This study investigated whether Fitbit devices can reduce sedentary behavior among employees in the workplace. Participants were asked to wear Fitbits during 8-hour work shifts, 5 days per week, for 8 weeks. They were instructed to stand at least once every 30 minutes throughout the workday. The goal of the study was to determine whether standing once every 30 minutes was a feasible strategy for reducing sedentary workplace behavior. On average, participants completed 36 of 40 workdays using Fitbits. The number of times participants stood during an 8-hour workday averaged 12 stands per day (maximum 16 stands per day). These results indicate that Fitbit technology is effective for recording and tracking interruptions in sitting time; however, to reduce sitting behavior, alternate approaches are required to motivate larger numbers of workers to participate.

Task-Specific Noise Exposure During Manual Concrete Surface Grinding in Enclosed Areas—Influence of Operation Variables and Dust Control Methods

Noise exposure is a distinct hazard during hand-held concrete grinding activities, and its assessment is challenging because of the many variables involved. Noise dosimeters were used to examine the extent of personal noise exposure while concrete grinding was performed with a variety of grinder sizes, types, accessories, and available dust control methods. Noise monitoring was conducted in an enclosed area covering 52 task-specific grinding sessions lasting from 6 to 72 minutes. Noise levels, either in minute average noise level (Lavg, dBA) or in minute peak (dBC), during concrete grinding were significantly (P < 0.01) correlated with general ventilation (GV: on, off), dust control methods (uncontrolled, wet, Shop-Vac, HEPA, HEPA-Cyclone), grinding cup wheel (blade) sizes of 4-inch (100 mm), 5-inch (125 mm) and 6-inch (150 mm), and surface orientation (horizontal, inclined). Overall, minute Lavg during grinding was 97.0 ± 3.3 (mean ± SD), ranging from 87.9 to 113. The levels of minute Lavg during uncontrolled grinding (98.9 ± 5.2) or wet-grinding (98.5 ± 2.7) were significantly higher than those during local exhaust ventilation (LEV) grinding (96.2 ± 2.8). A 6-inch grinding cup wheel generated significantly higher noise levels (98.7 ± 2.8) than 5-inch (96.3 ± 3.2) or 4-inch (95.3 ± 3.5) cup wheels. The minute peak noise levels (dBC) during grinding was 113 ± 5.2 ranging from 104 to 153. The minute peak noise levels during uncontrolled grinding (119 ± 10.2) were significantly higher than those during wet-grinding (115 ± 4.5) and LEV-grinding (112 ± 3.4). A 6-inch grinding cup wheel generated significantly higher minute peak noise levels (115 ± 5.3) than 5-inch (112 ± 4.5) or 4-inch (111 ± 5.4) cup wheels. Assuming an 8-hour work shift, the results indicated that noise exposure levels during concrete grinding in enclosed areas exceeded the recommended permissible exposure limits and workers should be protected by engineering control methods, safe work practices, and/or personal protective devices.

The timing and type of nursing staff occupational injury and illness incidents, Veterans Health Administration, 2002-2011: a retrospective, population-based, descriptive analysis

Background: While the majority of occupational injuries and illnesses that result in lost work days occur during typical day shift hours, the U.S. Bureau of Labor Statistics has noted that timing patterns often reflect the unique nature of different occupations. However, a literature search indicated that few studies have assessed the interplay between the timing and the type of nursing staff occupational injury and illness incidents in general, but especially so for those incidents that were recorded on an hourly basis. Methods : This decade-long retrospective population-based study ascertained the timing of diverse types of reported occupational injury or illness incidents among Veterans Health Administration (VHA) nursing employees, who were classified between the nurse, practical nurse, and nursing assistant series. Using January 1, 2002 as the start date for the longitudinal surveillance of incidents, descriptive analyses included 55,424 VHA nursing employees who reported a total of 113,708 incidents between 2002 and 2011, of which 106,216 (93.4%) were retained for this study, because they included both the specific time and the specific type of incident involved. Although nursing staff work shifts can vary widely, three “typical” 8-hour work shifts–that is to say, night shift: 23:01-07:00, day shift: 07:01-15:00, and evening shift: 15:01-23:00–were selected for summarizing study findings (i.e., for incidents that included both the specific time and the specific type of incident involved). Results: Findings indicated that male nursing staff (accounting for 15.4% of the applicable occupational injury and illness incidents) reported a larger percentage of “Assaults” and “Lifting (Patient Care)” incidents, especially during the evening and the night shifts, whereas female nursing staff (accounting for 84.6% of the applicable incidents) reported a larger percentage of “Slips, Trips, and Falls” incidents, but these were more likely to occur during the beginning and the end of each shift. Findings also indicated that, regardless of gender, “Assaults” and “Lifting (Patient Care)” incidents were more commonly reported during the evening and the night shifts, as compared with the day shift, between all three nursing occupations (nurse, practical nurse, and nursing assistant). “Slips, Trips, and Falls” incidents were more commonly reported during the beginning and end of each shift, between all three nursing occupations. Conclusions: Staffing patterns and nursing staff working conditions are risk factors for occupational injuries and illnesses. Findings suggest that more attention is needed for ascertaining the potential role and functioning of targeted injury prevention training initiatives with respect to the timing and potential likelihood of selected types of nursing staff occupational injury or illness incidents.

Governmental regulations for early retirement by means of energy expenditure cut offs

Long-term heavy work impairs employees, and they may retire prematurely by law. We investigated the value of energy expenditure (EE) during work shifts as a means to define heavy workload. The study comprised 79 male [mean age 32.2 (standard deviation [SD] 7.5) years] and 33 female [33.5 (SD 11.2) years] employees in different occupations classified as "heavy work" (EE of 1400 and 2000 kcal for women and men, respectively). Cycle ergometry determined exercise performance. Gas exchange measures were performed during selected phases of work, and heart rate (HR) recordings were obtained for a complete work shift. EE was calculated from gas exchange measures. Male and female subjects differed significantly for maximal power output (P(max)) [men=206.3 (SD 47.3) watts; women=149.6 (SD 36.1) watts] and maximal oxygen consumption (VO(2max)) [men=2.965 (SD 0.63) l/min; women= 1.958 (SD 0.50) l/min] in the cycle ergometer test. Shift HR (HR(Sh)) was found between 102 (SD 14) b/min [57.6 (SD 8.5) % HR(max)] and 99 (SD 10) b/min [55.5 (SD 5.9) % HR(max)] dependent on tasks and groups. Working EE was found between 1864 (SD 732) kcal and 1249 (SD 609) kcal for men and women, respectively, but approximately 60% of subjects were well below the legal limits. The legal definition of heavy workload by mean working EE per 8-hour work shift applies to all investigated occupations; however, a substantial proportion of workers may not fulfill the criterion if applied individually. Alternative definitions of heavy workload in terms of absolute oxygen consumption or EE relative to cardiorespiratory fitness lead to similar classification results of the investigated occupations.

A physically active occupation does not result in compensatory inactivity during out-of-work hours

Aim To examine differences in non-occupational physical activity behaviour in workers who engage in high and low occupational physical activity. Design Cross-sectional survey of 112 otherwise comparable volunteers in active (56 walking postal delivery workers) or inactive (56 administrative postal workers) occupations in Glasgow (Scotland) in 2007. Methods Twenty four-hour physical activity (steps and time standing, walking and sedentary) patterns were measured using activPAL™ for seven days. Comparisons were made during 8-hour work-shifts, during non-work hours on work-days and during the 2 non-work days. Results Age and body mass index of delivery and office staff, respectively, were (means (SD)) 38 (9) years versus 40 (7) years and 26.3 (3) kg m − 2 versus 27.4 (4) kg m − 2 . Delivery staff spent substantially longer time than office staff upright (6.0 (1.1) h versus 3.9 (1.5) h) and walking (3.1 (0.7) h versus 1.6 (0.7) h) and amassed more steps (16,035 (4264) versus 6709 (2808)) during 8-hour work-shifts and over 24 h on work days. During non-work hours of work-days and during non-work days, there were no significant differences in physical activity between the groups. The results were unchanged when the 15 women were excluded. Conclusion Having a more active occupation is not associated with more inactivity during non-work hours.

Environmental Tobacco Smoke Exposure Among Casino Dealers

This study quantified casino dealers' occupational exposure to environmental tobacco smoke (ETS). We measured casino dealers' exposure to ETS components by analyzing full-shift air and preshift and postshift urine samples. Casino dealers were exposed to nicotine, 4-vinyl pyridine, benzene, toluene, naphthalene, formaldehyde, acetaldehyde, solanesol, and respirable suspended particulates. Levels of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) in urine increased significantly during an 8-hour work shift both with and without adjustment for creatinine clearance. Creatinine-unadjusted cotinine significantly increased during the 8-hour shift, but creatinine-adjusted cotinine did not increase significantly. Casino dealers at the three casinos were exposed to airborne ETS components and absorbed an ETS-specific component into their bodies, as demonstrated by detectable levels of urinary NNAL. The casinos should ban smoking on their premises and offer employee smoking cessation programs.

Exposure to Suspended Chromium Compounds in Air and Its Association with Urinary β-2-Microglobulin Level among Welders in an Automotive Components Manufacturing Plant, Selangor

Introduction: The main objective of this study is to determine the correlation between suspended chromium concentrations and urinary β-2-microglobulin levels among welders in an automotive components manufacturing plant in Selangor. 49 welders and 39 workers involved in stamping process were selected as the exposed and the comparative group. β-2-microglobulin is a protein renal tubular dysfunction marker that can indicate renal dysfunction caused by heavy metal. Material and Methods: Air samples of worker’s breathing zone were collected using personal air sampling pump and filter papers. Filter paper were then diluted and analyzed with Atomic Absorption Spectrophotometry (AAS). Workers urine was collected at the end of 8-hour work shift and analyzed with β-2-microglobulin ELISA Kit (IBL-Hamburg) and a microtiter reader. Meanwhile, creatinine levels were analyzed with creatinine test strips and Reflotron®. Results: Mean concentrations of suspended chromium compounds in air for the exposed group was 0.135±0.043µg/m3 while for the non-exposed group was 0.124±0.029µg/m3 . The mean level of urinary β-2-microglobulin per creatinine for the exposed group was 84.996±39.246µg/g while that of the comparative group was 61.365±21.609 µg/g. The concentrations of suspended chromium compounds were higher in the exposed group compared to the comparative group (Z=-2.444, p=0.015). β-2-microglobulin level was also higher in the exposed group compared to the non-exposed group (t=3.821, p=<0.001). However, there was no significant correlation between suspended chromium compounds in air and urinary β-2-microglobulin levels (r=0.080, p=0.457) among the respondents. A multiple stepwise regression analysis showed that the most influence variable or confounding factor to β-2-microglobulin level was the education year (β =-0.020, p=0.010). Conclusion: All respondents were exposed to concentrations of chromium below regulated limit. Years of education seemed to be a secondary factor that influenced β-2-microglobulin level.

Exposure to Suspended Chromium Compounds in Air and its Association With Urinary B2-Microglobulin Level Among Welders in an Automotive Components Manufacturing Plant in Malaysia

P-760 Introduction: The main objective of this study is to determine the correlation between suspended chromium concentrations and urinary B2-microglobulin levels among welders in an automotive components manufacturing plant in Selangor, Malaysia. Forty-nine welders and 39 workers involved in stamping process were selected as the exposed and the comparative group. B2-microglobulin is a protein renal tubular dysfunction marker that can indicate renal dysfunction caused by heavy metal. Material and Methods: Air samples of worker's breathing zone were collected using personal air sampling pump and filter papers. Filter paper were then diluted and analyzed with Atomic Absorption Spectrophotometry (AAS). Workers urine was collected at the end of 8-hour work shift and analyzed with B2-microglobulin ELISA Kit (IBL-Hamburg) and a microtiter reader. Meanwhile, creatinine levels were analyzed with creatinine test strips and Reflotron®. Results: Mean concentrations of suspended chromium compounds in air for the exposed group was 0.135±0.043μg/m3 while for the non-exposed group was 0.124±0.029μg/m3. The mean level of urinary B2-microglobulin per creatinine for the exposed group was 84.996±39.246μg/g while that of the comparative group was 61.365±21.609 μg/g. The concentrations of suspended chromium compounds were higher in the exposed group compared to the comparative group (Z=−2.444, p=0.015). B2-microglobulin level was also higher in the exposed group compared to the non-exposed group (t=3.821, p=<0.001). However, there was no significant correlation between suspended chromium compounds in air and urinary B2-microglobulin levels (r=0.080, p=0.457) among the respondents. A multiple stepwise regression analysis showed that the most influence variable or confounding factor to B2-microglobulin level was the education year (B =−0.020, p=0.010). Conclusion: All respondents were exposed to concentrations of chromium below regulated limit. Years of education seemed to be a secondary factor that influenced B2-microglobulin level. Keywords: welders, suspended chromium compounds, urinary B2-microglobulin, automotive components manufacturing plant

Exposure to inhalable flour dust in Canadian flour mills.

In 1999, the American Conference of Governmental Industrial Hygienists (ACGIH(R)) proposed a Threshold Limit Value (TLV(R)) of 0.5 mg/m(3) for flour dust with a sensitization notation. The Labour Program of the Department of Human Resources Development Canada (HRDC), following notice of the intention to set a TLV, conducted a study of the levels of exposure to flour dust in flour mills across Canada to verify existing conditions, as well as to decide whether to adopt the proposed TLV or reference some other value. As part of the study, a relationship between flour dust concentrations obtained by using Institute of Occupational Medicine (IOM) samplers and closed-face 37-mm cassettes was examined and the literature on the health effects of exposure to flour dust was reviewed. A total of 104 millers, packers, sweepers, bakery mix operators, and others (mixed tasks) from 14 flour mills were sampled over an 8-hour work shift using IOM samplers. The results indicate that 101 employees (97.1%) were exposed to levels exceeding 0.5 mg/m(3), 66 employees (67.3%) to levels exceeding 5 mg/m(3), and 44 employees (42.3%) to levels exceeding 10 mg/m(3). For comparison purposes, flour dust measurements were also taken in a highly automated flour mill using state-of-the-art technology. The results suggest that even with the most up-to-date technology and proper cleaning operations in place, the flour milling industry may not be able to reduce the flour dust levels to below the TLV of 0.5 mg/m(3). According to the measurements of inhalable and total dust concentrations, the IOM sampler appears to be a more efficient collector of inhalable airborne particles up to 100 microm than the closed-face 37-mm cassette.

Effectiveness of Sumatriptan in Reducing Productivity Loss Due to Migraine: Results of a Randomized, Double-Blind, Placebo-Controlled Clinical Trial

To determine the effect of sumatriptan on migraine-related workplace productivity loss. In this randomized, double-blind, placebo-controlled, parallel-group trial, adult migraineurs self-injected 6 mg of sumatriptan or matching placebo to treat a moderate or severe migraine within the first 4 hours of a minimum of an 8-hour work shift. Outcome measures included productivity loss and number of patients returning to normal work performance 2 hours after injection and across the work shift, time to return to normal work performance, and time to headache relief. A total of 206 patients underwent screening, 140 (safety population) of whom returned for clinic treatment. Of these 140 patients, 119 received migraine treatment in the workplace (intent-to-treat population), 116 of whom comprised the study population. Of these 116 patients, 76 self-administered sumatriptan, and 40 self-administered placebo. Sumatriptan treatment tended to reduce median productivity loss 2 hours after injection compared with placebo (25.2 vs 29.9 minutes, respectively; P = .14). Significant reductions in productivity loss were obtained across the work shift after sumatriptan treatment compared with placebo (36.8 vs 72.6 minutes, respectively; P = .001). Significantly more sumatriptan-treated patients vs placebo-treated patients experienced shorter return to normal work performance at 2 hours (53/76 [70%] vs 12/40 [30%], respectively) and across the work shift (64/76 [84%] vs 23/40 [58%], respectively; P < .001). Significantly more sumatriptan-treated patients experienced headache relief 1 hour after injection compared with placebo-treated patients (48/76 [63%] vs 13/40 [33%], respectively; P = .004). Across an 8-hour work shift, sumatriptan was superior to placebo in reducing productivity loss due to migraine.

Hot Occupation and Nephrolithiasis

We investigated the prevalence of stone disease and urinary stone risk factors in machinists chronically exposed to a hot environment and massive sweating, without interference of nephrotoxic metals or other lithogenic compounds. The study was performed at a glass plant and exposure to heat stress was estimated by the Wet Bulb Globe Temperature climatic index. The prevalence of nephrolithiasis on the entire population of the machinists was 8.5% (20 of 236), while the prevalence on the controls working in normal temperature was 2.4% (4 of 165) (p = 0.03). A high incidence (38.8%) of uric acid stones was present in the workers exposed to heat stress. Among the urinary stone risk indexes determined for 3 days during the 8-hour work shift on a randomly selected sample of 21 workers exposed and 21 workers not exposed to heat stress without any evidence of stone disease significant differences were found in uric acid concentration (722 ± 195 versus 482 ± 184mg./l., p < 0.001), specific gravity (1,026 ± 4 versus 1,021 ± 6, p <0.005) and pH (5.31 ± 0.28 versus 5.64 ± 0.54, p < 0.02), respectively. Thus, high uric acid relative supersaturation was present during occupation in hot temperatures (8.67 ± 3.49) compared to occupation in normal temperatures (4.15 ± 2.7) (p < 0.001). This study confirms that chronic dehydration represents a real lithogenic risk factor, mainly for uric acid stones, and adequate fluid intake is recommended during hot occupations.

A psychophysiological study of high and very high frequency manual materials handling: Part I - Lifting and lowering

This paper describes the first part of a two-part study undertaken to determine the psychophysical and physiological responses of male workers to short duration (2 hours), high (up to 16 times per minute) and very high (above 16 times per minute) frequency manual handling tasks. Manual lifting and lowering tasks were studied in the first part of the study. The handling frequencies investigated were: 14, 16, 18, 20, and 22 per minute. Ten highly trained males participated in the study. Their metabolic energy expenditure rate, heart rate, and ratings of perceived exertion (RPE) of the shoulders, back, and whole body at the maximum acceptable weight of lift/lower were determined. How the physiological responses changed with the working duration was also investigated. The results indicated that heart rate and oxygen uptake remained steady with the working duration. Although the maximum acceptable weight declined significantly with frequency, the sample population chose a consistent work rate (approximately 145 kg-m/min, on the average). Other responses, however, were not affected significantly by frequency. Also, on the average, subjects performing manual lifting tasks operated at approximately 60% of their lifting aerobic capacity (equivalent to approximately 57% of their graded treadmill aerobic capacity). Subjects performing lowering tasks operated at 55% of their lifting aerobic capacity, on the average (equivalent to approximately 52% of their graded treadmill aerobic capacity). These findings are substantially different from those observed in previous studies for 8-hour work shifts and lower frequencies and indicate that individuals performing high and very high frequency manual lifting or lowering tasks are subjected to very high physical and physiological burden.

Environmental and biological monitoring of methyl ethyl ketone (MEK)

This study was conducted to evaluate the usefulness of various biological parameters for monitoring of workers exposed to methyl ethyl ketone (MEK). Fifty male workers from a large magnetic videotape factory participated in this study. Personal air samples were collected using 3M organic vapor monitors and analysed for MEK by gas chromatography with flame ionisation detector (FID). 10 mL of urine; blood (1 mL) and exhaled air were also collected at the end of an 8-hour workshift. The headspace GC method was applied for measurement of urinary and blood MEK. MEK in expired air was analysed directly by using a GC/FID.The correlation coefficients (r) between environmental MEK and all other biological parameters measured show significant positive relationships. The r for environmental MEK and urine MEK was 0.84; for blood 0.73 and for breath 0.64. The correlation coefficients between blood and urine was 0.72; blood and breath was 0.88 and urine and breath 0.60. These findings suggest that measurements of unmetabolised MEK in blood, exhaled air and urine can be used for biological monitoring of MEK exposure. Nevertheless, laboratory methodological assessment is in favour of measuring urinary MEK as it is non-invasive and does not have to be analysed immediately after collection.