scholarly journals Measuring and Mitigating Mercury Gases in the Museums Victoria Collection.

2018 ◽  
Vol 2 ◽  
pp. e27044 ◽  
Author(s):  
Danielle Measday ◽  
Rosemary Goodall
Keyword(s):  
Weighted Average ◽  
Mitigation Strategies ◽  
Hazardous Substances ◽  
Mercury Chloride ◽  
Mercury Vapour ◽  
Exposure Level ◽  
Engineering Controls ◽  
Mercury Compounds ◽  
Scientific Equipment ◽  
Time Weighted Average

For the past six years the conservation and collection management departments at Museums Victoria have been conducting a major survey to determine the type and extent of hazardous substances in the collections to better inform safe handling and storage practices. This paper focuses on mercury compounds in the collection, including mercury chloride applied as a pesticide, mercury sulfide pigments, liquid mercury used in scientific equipment, and mineral specimens such as native mercury and cinnabar. All these compounds can release volatile mercury vapour into storage furniture and have the potential to contaminate both the cabinet and other specimens stored nearby. Although previous testing had confirmed that the air in storage rooms and workspaces contained no detectable levels of mercury vapour, recent publications by Hawks et al. 2004, Havermans et al. 2015 and Marcotte et al. 2017 showing high levels of mercury vapour inside storage containers in herbaria raised concern that there could be higher than acceptable levels of mercury vapour building up inside storage cabinets at Museums Victoria. This prompted analysis of the headspace in cabinets using a Jerome J405 portable mercury vapour meter. Testing was informed by the results of previous hazards surveys using X-ray fluorescence spectrography to target cabinets where mercury vapour was likely to be present. Air from cabinets was sampled across the indigenous cultures, history, technology and natural sciences collections. Results showed levels of mercury vapour could be considerably above 25 μg/m3 the Australian time-weighted average (TWA) exposure standard for an 8 hour workday in cabinets of bird skins and indigenous artefacts treated with mercuric chloride pesticides. Results above 150 μg/m3 the temporary emergency exposure level (TEEL) were measured in the mineralogy collection. Mitigation strategies are being implemented to reduce the risks to staff health and contamination of other collection materials, including enclosing mercury-containing species of minerals in gas barrier film, venting high risk cabinets to dissipate vapour before accessing specimens, and engineering controls during the handling of specimens.

scholarly journals Repeated Noise Exposure Does Not Reach Hazardous Levels During Total Joint Arthroplasty

2020 ◽  
Vol 185 (9-10) ◽  
pp. e1551-e1555
Author(s):  
Sean E Slaven ◽  
Benjamin M Wheatley ◽  
Daniel L Christensen ◽  
Sameer K Saxena ◽  
Robert J McGill
Keyword(s):  
Noise Exposure ◽  
Weighted Average ◽  
Sound Level ◽  
Health Concern ◽  
Exposure Level ◽  
Total Knee ◽  
Time Weighted Average ◽  
Exposure Levels ◽  
Occupational Standards ◽  
Level Meter

Abstract Introduction Noise exposure is an occupational health concern for certain professions, especially military servicemembers and those using power tools on a regular basis. The purpose of this study was to quantify noise exposure during total hip arthroplasty (THA) and total knee arthroplasty (TKA) cases compared to the recommended standard for occupational noise exposure. Materials and Methods A sound level meter was used to record cumulative and peak noise exposure levels in 10 primary THA and 10 primary TKA surgeries, as well as 10 arthroscopy cases as controls. Measurements at the distance of the surgeon were taken in all cases. In TKA cases, measurements were taken at 3 feet and 8 feet from the surgeon, to simulate the position of the anesthetist and circulating nurse, respectively. Results Time-weighted average was significantly higher in THA (64.7 ± 5.2 dB) and TKA (64.5 ± 6.8 dB) as compared to arthroscopic cases (51.1 ± 7.5 dB, P < 0.001) and higher at the distance of the surgeon (64.5 ± 6.8 dB) compared to the anesthetist (52.9 ± 3.8 dB) and the circulating nurse (54.8 ± 11.2 dB, P = 0.006). However, time-weighted average was below the recommended exposure level of 85 dB for all arthroplasty cases. Peak levels did not differ significantly between surgery type or staff role, and no values above the ceiling limit of 140 dB were recorded. Surgeon’s daily noise dose percentage per case was 1.78% for THA and 2.04% for TKA. Conclusion Noise exposure in THA and TKA was higher than arthroscopic cases but did not exceed occupational standards. A daily dose percentage of approximately 2% per case indicates that repeated noise exposure likely does not reach hazardous levels in modern arthroplasty practice.

3-Nitro-1,2,4-triazol-5-one (2014)

2017 ◽  
Vol 34 (1) ◽  
pp. 8-14 ◽  
Keyword(s):  
Reproductive Toxicity ◽  
Liver Microsomes ◽  
Weighted Average ◽  
Exposure Level ◽  
Inhalation Toxicity ◽  
Developmental Studies ◽  
Developmental Defects ◽  
Toxicity Studies ◽  
Time Weighted Average ◽  
Rats And Mice

3-Nitro-1,2,4-triazol-5-one (NTO) is a potential replacement for energetics in military munitions. It is a component of IMX-101, a munition designed to prevent unintentional detonation. This report summarizes the dermal, oral, and inhalation animal toxicity data, including the results of genotoxicity and limited reproductive and developmental studies. NTO has an acute LD50 in rats and mice of >5000 mg/kg, is a potential eye and skin irritant, but does not induce skin sensitization. Acute inhalation toxicity studies in rats were negative, but testicular hypoplasia was observed in a 14-day oral study in rats administered NTO at >500 mg/kg/day. Similar findings were noted in an oral 90-day study at dosages >315 mg/kg/day and in reproductive toxicity studies at >125 mg/kg/day. NTO did not cause any developmental defects. All genotoxicity studies were negative. ADME and pharmacokinetics data showed rapid uptake and elimination of NTO from both inhalation and oral intakes. Biotransformation by liver microsomes demonstrated two separate pathways, one aerobic and the other anaerobic. NTO is not considered an endocrine disruptor. There is very little human data regarding NTO or the IMX-101 mixtures. Using testicular changes in rats as the point of departure for deriving a Workplace Environmental Exposure Level (WEEL) for NTO, the resulting BMDL10 was 40 mg/kg/day, and the 8-hour time-weighted average was 2 mg/m2.

scholarly journals Treatment of thoracolumbar burst fractures: extended follow-up of a randomized clinical trial comparing orthosis versus no orthosis

2017 ◽  
Vol 27 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Jennifer C. Urquhart ◽  
Osama A. Alrehaili ◽  
Charles G. Fisher ◽  
Alyssa Fleming ◽  
Parham Rasoulinejad ◽  
...  
Keyword(s):  
Outcome Measures ◽  
Weighted Average ◽  
Average Treatment Effect ◽  
Secondary Outcome ◽  
Thoracolumbar Burst Fractures ◽  
Treatment Comparison ◽  
Average Treatment ◽  
Burst Fractures ◽  
Time Weighted Average

OBJECTIVEA multicenter, prospective, randomized equivalence trial comparing a thoracolumbosacral orthosis (TLSO) to no orthosis (NO) in the treatment of acute AO Type A3 thoracolumbar burst fractures was recently conducted and demonstrated that the two treatments following an otherwise similar management protocol are equivalent at 3 months postinjury. The purpose of the present study was to determine whether there was a difference in long-term clinical and radiographic outcomes between the patients treated with and those treated without a TLSO. Here, the authors present the 5- to 10-year outcomes (mean follow-up 7.9 ± 1.1 years) of the patients at a single site from the original multicenter trial.METHODSBetween July 2002 and January 2009, a total of 96 subjects were enrolled in the primary trial and randomized to two groups: TLSO or NO. Subjects were enrolled if they had an AO Type A3 burst fracture between T-10 and L-3 within the previous 72 hours, kyphotic deformity < 35°, no neurological deficit, and an age of 16–60 years old. The present study represents a subset of those patients: 16 in the TLSO group and 20 in the NO group. The primary outcome measure was the Roland Morris Disability Questionnaire (RMDQ) score at the last 5- to 10-year follow-up. Secondary outcome measures included kyphosis, satisfaction, the Numeric Rating Scale for back pain, and the 12-Item Short-Form Health Survey (SF-12) Mental and Physical Component Summary (MCS and PCS) scores. In the original study, outcome measures were administered at admission and 2 and 6 weeks, 3 and 6 months, and 1 and 2 years after injury; in the present extended follow-up study, the outcome measures were administered 5–10 years postinjury. Treatment comparison between patients in the TLSO group and those in the NO group was performed at the latest available follow-up, and the time-weighted average treatment effect was determined using a mixed-effects model of longitudinal regression for repeated measures averaged over all time periods. Missing data were assumed to be missing at random and were replaced with a set of plausible values derived using a multiple imputation procedure.RESULTSThe RMDQ score at 5–10 years postinjury was 3.6 ± 0.9 (mean ± SE) for the TLSO group and 4.8 ± 1.5 for the NO group (p = 0.486, 95% CI −2.3 to 4.8). Average kyphosis was 18.3° ± 2.2° for the TLSO group and 18.6° ± 3.8° for the NO group (p = 0.934, 95% CI −7.8 to 8.5). No differences were found between the NO and TLSO groups with time-weighted average treatment effects for RMDQ 1.9 (95% CI −1.5 to 5.2), for PCS −2.5 (95% CI −7.9 to 3.0), for MCS −1.2 (95% CI −6.7 to 4.2) and for average pain 0.9 (95% CI −0.5 to 2.2).CONCLUSIONSCompared with patients treated with a TLSO, patients treated using early mobilization without orthosis maintain similar pain relief and improvement in function for 5–10 years.

scholarly journals Exposure to Ultrafine Particles in the Ferroalloy Industry Using a Logbook Method

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2546
Author(s):  
Rikke Bramming Jørgensen ◽  
Ida Teresia Kero ◽  
Aleksander Blom ◽  
Esten Eide Grove ◽  
Kristin von Hirsch Svendsen
Keyword(s):  
Exposure Assessment ◽  
Ultrafine Particles ◽  
Weighted Average ◽  
Average Concentration ◽  
Respirable Particles ◽  
Exposure Estimation ◽  
Close Proximity ◽  
Personal Sampling ◽  
Time Weighted Average ◽  
Stationary Sampling

Background: It is difficult to assess workers’ exposure to ultrafine particles (UFP) due to the lack of personal sampling equipment available for this particle fraction. The logbook method has been proposed as a general method for exposure assessment. This method measures the time and concentration components of the time-weighted average concentration separately and could be suitable for investigation of UFP exposure. Objectives: In this study, we have assessed workers’ exposure to UFP in a ferrosilicon plant. The main tasks of the furnace workers were identified, and the logbook method was used in combination with stationary measurements of UFP taken as close to the identified task areas as possible. In order to verify the results, respirable particles were collected using stationary sampling in close proximity to the UFP measuring instrument, and personal full-shift sampling of respirable particles was performed simultaneously. Thus, exposure to respirable particles determined using the logbook method could be compared to the results of standard measurement. Methods: The particle number concentration of ultrafine particles was determined using a NanoScan SMPS. Respirable particle concentration and exposure were determined using a sampling train consisting of a pump, filter, filter cassettes, and SKC Cyclone for the respirable fraction. Attendance times for workers at each work location were registered via thorough observations made by the research team. Results: The logbook method for exposure estimation based on stationary sampling equipment made it possible to calculate UFP exposure for workers operating the furnaces at a ferrosilicon plant. The mid-size furnace and the large furnace were evaluated separately. The workers operating the largest furnace were exposed to 1.47 × 104 particles/cm3, while workers operating the mid-size furnace were exposed to 2.06 × 104 particles/cm3, with a mean of 1.74 × 104 particles/cm3. Substantial contributions from the casting area, ladle transport corridor, and both tapping areas were made. Exposure to respirable particles was 2.04 mg/m3 (logbook); 2.26 mg/m3 (personal sampling) for workers operating the large-sized furnace, 3.24 mg/m3 (logbook); 2.44 mg/m3 (personal sampling) for workers operating the medium-sized furnace, and 2.57 mg/m3 (logbook); 2.53 mg/m3(personal sampling) on average of all tappers. The average ratio of these two methods’ results was 1.02, which indicates that the logbook method could be used as a substitute for personal sampling when it is not possible to perform personal sampling, at least within this industry. Conclusions: The logbook method is a useful supplement for exposure assessment of UFP, able to identify the most polluted areas of the workplace and the contribution of different work tasks to the total exposure of workers, enabling companies to take action to reduce exposure.

Evaluation of a simple, inexpensive, in situ sampler for measuring time-weighted average concentrations of suspended sediment in rivers and streams

2019 ◽  
Vol 33 (5) ◽  
pp. 678-686 ◽  
Author(s):  
Nicholas J.C. Doriean ◽  
Peter R. Teasdale ◽  
David T. Welsh ◽  
Andrew P. Brooks ◽  
William W. Bennett
Keyword(s):  
Suspended Sediment ◽  
Weighted Average ◽  
Measuring Time ◽  
Rivers And Streams ◽  
Time Weighted Average

scholarly journals Effects of elevated CO2 levels on lung immune response to organic dust and lipopolysaccaride

2021 ◽  
Author(s):  
David Schneberger ◽  
Upkardeep Singh Pandher ◽  
Brooke Thompson ◽  
Shelley Kirychuk
Keyword(s):  
Immune Responses ◽  
Inflammatory Responses ◽  
Animal Feed ◽  
Weighted Average ◽  
Innate Immune ◽  
Mrna Levels ◽  
Innate Immune Responses ◽  
Organic Dust ◽  
Complex Environments ◽  
Time Weighted Average

Abstract Workplaces with elevated organic dust levels such as animal feed barns also commonly have elevated levels of gasses, such as CO2. Workers exposed to such complex environments often experience respiratory effects that may be due to a combination of respirable factors. We examined the effects of CO2 at the ASHRAE recommended limit (1000 ppm) as well as the EPA 8hr time weighted average limit (5000 ppm) on lung innate immune responses in mice with exposure to inflammatory lipopolysaccharide and organic dust. Mice were nasally instilled with dust extracts or LPS and immediately put into chambers with a constant flow of room air (approx. 430 ppm CO2), 1000 ppm, or 5000 ppm CO2 enriched air. Organic dust exposures tended to show decreased inflammatory responses with 1000 ppm CO2 and increased responses at 5000 ppm CO2. Conversely, LPS with addition of CO2 as low as 1000 ppm tended to inhibit several inflammatory markers. In most cases saline treated animals showed few changes with CO2 exposure, though some changes in mRNA levels were present. This shows that CO2 as low as 1000 ppm CO2 was capable of altering innate immune responses to both LPS and organic dust extracts, but each response was altered in a different fashion.

scholarly journals A risk control framework for safe manufacturing workstations in view of COVID-19

2020 ◽  
Vol 327 ◽  
pp. 03007
Author(s):  
Ebly Sanchez ◽  
Knut Åkesson
Keyword(s):  
Problem Solving ◽  
Manufacturing Industry ◽  
Close Contact ◽  
Mitigation Strategies ◽  
Assessment Model ◽  
Protection Measures ◽  
Industrial Plants ◽  
Engineering Controls ◽  
Risk Levels ◽  
Control Framework

The manufacturing industry resumes operations after the COVID-19 pandemic supported by return-to-work guidelines, which are mostly personal protection measures for the workers and employees. In this paper, we propose a framework for assessing risk at the workstation level by linking the risk levels to possible mitigation strategies that can be implemented using standard operating procedures (SOP), 5S and problem-solving. Within industrial plants, operators work in close contact with coworkers and supervisors, and they are also sharing tools and machines. It is therefore, essential to develop strategies that reduce the operator’s exposure to viruses in the workplace. The purpose of this work is that when implemented, the risk assessment model and specifically how SOP, 5S and problem solving can be used to implement administrative and engineering controls resulting in a safe workplace and increasing level of confidence for the operators working within the plant.

scholarly journals Benzene Exposure and Biomarkers in Alveolar Air and Urine Among Deck Crews on Tankers Transporting Gasoline

2019 ◽  
Vol 63 (8) ◽  
pp. 890-897 ◽  
Author(s):  
Karl Forsell ◽  
Ingrid Liljelind ◽  
Göran Ljungkvist ◽  
Rolf Nordlinder ◽  
Eva Andersson ◽  
...  
Keyword(s):  
Weighted Average ◽  
Occupational Exposures ◽  
Exposure Level ◽  
Respiratory Protection ◽  
Muconic Acid ◽  
Alveolar Air ◽  
Benzene Exposure ◽  
Exposure Limit ◽  
Level Of Significance ◽  
Post Shift

Abstract Introduction Increased rates of leukaemia have been found among tanker crews. Occupational exposures to the leukomogen benzene during loading, unloading, and tank cleaning are possible causes. Studies on older types of tankers carrying gasoline with most handling being done manually have revealed important exposures to benzene. Our study explores benzene exposures on tankers with both automatic and manual systems. Correlations between benzene exposure and benzene in alveolar air (AlvBe), benzene in urine (UBe), and trans,trans-muconic acid (ttMA) in urine were investigated. Methods Forty-three male seafarers (22 deck crewmembers and 21 not on deck) on five Swedish different product and chemical tankers transporting 95- or 98-octane gasoline were investigated between 1995 and 1998. The tankers used closed systems for the loading and unloading of gasoline but stripping and tank cleaning were done manually. Benzene in respiratory air was measured using personal passive dosimeters during a 4-h work shift. Samples for biomarker analyses were collected pre- and post-shift. Smoking did occur and crewmembers did not use any respiratory protection during work. Results The average 4-h benzene exposure level for exposed was 0.45 mg m−3 and for non-exposed 0.02 mg m−3. Benzene exposure varied with type of work (range 0.02–143 mg m−3). AlvBe, UBe, and ttMA were significantly higher in post-shift samples among exposed and correlated with exposure level (r = 0.89, 0.74, and 0.57, respectively). Smoking did not change the level of significance among exposed. Discussion Benzene in alveolar air, unmetabolized benzene, and ttMA in urine are potential biomarkers for occupational benzene exposure. Biomarkers were detectable in non-exposed, suggesting benzene exposure even for other work categories on board tankers. Work on tankers carrying gasoline with more or less closed handling of the cargo may still lead to significant benzene exposure for deck crewmembers, and even exceed the Swedish Occupational Exposure Limit (OEL; 8-h time-weighted average [TWA]) of 1.5 mg m−3.

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