Mixmaster exposure to dust during mixing of wildland fire retardant chemicals

2002 ◽  
Vol 11 (1) ◽  
pp. 65
Author(s):  
Terry M. Spear ◽  
Curtis E. Cannell
Keyword(s):  
Hydrogen Cyanide ◽  
Wildland Fire ◽  
Weighted Average ◽  
Fire Retardant ◽  
Assessment Model ◽  
Respirable Dust ◽  
Personal Hygiene ◽  
Exposure Limits ◽  
Local Exhaust Ventilation ◽  
End Use

A study was performed at two air tanker/retardant bases to determine the mixmaster’s exposure to dust derived from mixing dry fire retardant compounds. Personal sampling for both inhalable and respirable dust was conducted while the mixmaster mixed fire retardant compounds to form a retardant slurry. Personal samples were also analysed for a colorant in the retardants and hydrogen cyanide. Hazard quotients were calculated for average and upper-end use scenarios using a risk assessment model from Labat-Anderson, Incorporated. The exposure analysis revealed that the 8-h time weighted average (TWA) concentrations were within applicable occupational exposure limits for the inhalable and respirable dust fractions as well as for the colorant and hydrogen cyanide. When the mean inhalable exposure concentration was used to calculate chemical intake, hazard quotients were above 1 at both retardant bases, indicating a potential for non-carcinogenic health effects. Exposure control methods recommended from this study include substitution of a liquid concentrate fire retardant, installation of local exhaust ventilation systems, good housekeeping and personal hygiene. We also recommend the use of personal protective equipment including a filtering facepiece, half-mask respirator; eye protection, and protective clothing such as gloves and coveralls.

Occupational Exposure Risk for Swine Workers in Confined Housing Facilities

2019 ◽  
Vol 25 (1) ◽  
pp. 37-50 ◽  
Author(s):  
Alvin C. Alvarado ◽  
Bernardo Z. Predicala
Keyword(s):  
Hydrogen Sulfide ◽  
Occupational Exposure ◽  
Weighted Average ◽  
Respirable Dust ◽  
Exposure Risk ◽  
Exposure Limits ◽  
Exposure Limit ◽  
Short Term Exposure ◽  
Swine Workers ◽  
Time Weighted Average

Abstract. Extended exposure of swine barn workers to noise and airborne contaminants has been reported to be associated with various health problems. In this study, the actual exposure of workers to respirable dust, gases (ammonia and hydrogen sulfide), and noise in swine production operations was monitored in order to determine the contribution of specific activities in the barn to potential adverse health impacts to swine workers. Selected workers in a swine barn facility were outfitted with a personal monitoring system that included a respirable dust sampler, ammonia (NH3) and hydrogen sulfide (H2S) gas monitors, and a noise dosimeter as they performed their regular duties during their workday. From a total of 50 monitoring days spanning winter and summer months, results showed that the occupational exposure of swine workers to respirable dust, NH3, H2S, and noise while performing their daily assigned tasks was generally below the respective time-weighted average exposure limits for each hazard. However, a number of tasks showed high likelihood for elevated occupational exposure risk. Respirable dust concentrations exceeded the time-weighted average limit of 3 mg m-3 while feeding and weighing pigs. These activities also exceeded the short-term exposure limit (35 ppm) for NH3. Dangerous levels of H2S were generated when draining manure from manure collection pits in the production rooms. Noise levels exceeded the recommended 15 min exposure limit (100 dBA) when weighing and loading pigs for market. The occupational exposure risks for workers to barn contaminants can be reduced through measures that control the generation of contaminants at their source, by removing generated contaminants from the work environment, as well as by outfitting the workers with protective devices that prevent personal exposure to contaminants. Keywords: Ammonia, Barn worker, Dust, Hydrogen sulfide, Noise, Occupational exposure, Risk, Swine.

scholarly journals Potential of Passive Sampling and Plant Absorption to Quantify Inhalation Exposure to Volatile Organic Compounds

2020 ◽  
Vol 19 (1) ◽  
pp. 43-56
Author(s):  
Veerapas Na Roi-et ◽  
◽  
Supawat Chaikasem ◽  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Indoor Air Pollution ◽  
Inhalation Exposure ◽  
Hazard Index ◽  
Weighted Average ◽  
Exposure Limits ◽  
Potential Health ◽  
Limit Values ◽  
Volatile Organic

Emission of volatile organic compounds (VOCs) from photocopiers was investigated to assess the potential health impacts on inhalation exposure to VOCs. VOCs samples were collected during working hours using SKC VOCs 575 series passive sample. Twenty-one quantified VOCs were measured and analyzed by GC-MS/MS. The results showed that the total VOCs concentration emitted in the photocopy centers A and B were 2.29×104 and 2.32×104 µg/m3, respectively. The highest detected chemical was trans-1,2-Dichloroethene at about 2.18×104 (photocopy center A) and 2.15×104 µg/m3 (photocopy center B (The results reveal that the non-carcinogenic risk for inhalation exposure to m-Xylene, p-Xylene, and trans-1,2-Dichloroethene were in the range 0.94-1.53 and 1.19-1.79 and 51.54-52.23, respectively, resulting in the hazard index (HI) of non-carcinogenic VOCs in total being greater than 1.0. This indicated that the cumulative effects of inhalation exposure to VOCs at low concentrations should be of concern, even though it does not exceed the occupational exposure limits and Threshold Limit Values-Time Weighted Average for the mixtures (TLV-TWAmix). Plants display a greener solution to reduce indoor air pollution. The bio-concentration levels of total VOCs in Epipremnum aureum were noted as 74.71 to 174.42, signifying that E. aureum is effective for removal of VOCs naturally and sustainably.

scholarly journals The role of advanced end-use technologies in long-term climate change mitigation: the interlinkage between primary bioenergy and energy end-use

2020 ◽  
Vol 163 (3) ◽  
pp. 1659-1673 ◽  
Author(s):  
Junichi Tsutsui ◽  
Hiromi Yamamoto ◽  
Shogo Sakamoto ◽  
Masahiro Sugiyama
Keyword(s):  
Land Use ◽  
Carbon Capture And Storage ◽  
Integrated Assessment Model ◽  
Assessment Model ◽  
Carbon Budgets ◽  
Environmental Implications ◽  
Multiple Series ◽  
Wide Range ◽  
End Use

AbstractThe role of advanced end-use technologies has been investigated in multiple series of scenarios using an integrated assessment model BET-GLUE, which comprises an energy-economic module (BET) and a bioenergy-land-use module (GLUE). The scenarios consider different technology assumptions on the availability of bioenergy with carbon capture and storage (BECCS) and end-use efficiencies featuring electrification under a wide range of carbon price trajectories, which start at 1–690 USD/tCO2 in 2030, increase at 4.5%/year, and level off in 2100. This scenario design allows close examination of energy, economic, and environmental implications of different levels of policy stringency and carbon budgets. While improving end-use efficiencies consistently decrease policy costs for a wide range of carbon budgets, the value of BECCS availability in terms of cost reduction is crucial only in a limited range toward lower budgets. Constraints on BECCS, including those indirectly imposed by the limited bioenergy supply, also tend to narrow the lower range of attainable budget levels, indicating technological and economic challenges, although they may have an impact on reducing the total budget including land-use emissions. Overall, the advanced end-use efficiency has a significant effect on the required level of policy stringency for a given climate goal, so that it can compensate for the biomass constraints.

An analysis of workplace exposures to asbestos at three steel mills located in the United States (1972-1982)

2019 ◽  
Vol 35 (11-12) ◽  
pp. 726-737
Author(s):  
Dana Hollins ◽  
Amanda Burns ◽  
Ken Unice ◽  
Dennis J Paustenbach
Keyword(s):  
Occupational Safety ◽  
Weighted Average ◽  
Open Hearth ◽  
The United States ◽  
Blast Furnaces ◽  
Health Administration ◽  
Steel Mill ◽  
Exposure Limits ◽  
Steel Mills ◽  
Safety And Health

The objective is to present historical asbestos airborne concentrations associated with activities involving presumably asbestos-containing materials in steel mills. A total of 138 historical industrial hygiene air samples collected in three US steel mills from 1972 to 1982 were analyzed. The majority of samples were collected during relining of open hearth furnaces, stoves, and blast furnaces by steel mill bricklayers and bricklayer helpers. Over 75% of the samples ( n = 106) were collected for 50 min or less, four samples were collected for 227 to 306 min, and sample durations were not reported for the remaining 28 samples. Average airborne fiber concentrations measured during relining activities of open hearth furnaces, stoves, and blast furnaces were 0.21 f/cc, 0.72 f/cc and 0.13 f/cc phase-contrast microscopy (PCM), respectively. Measured airborne fiber concentrations of four time-weighted average (TWA) samples (>227 min) averaged 0.045 f/cc. Estimated 8-h TWAs concentrations averaged 0.34 f/cc for bricklayers and 0.2 f/cc bricklayer helpers. While 8-h TWA concentration estimates for monitored tasks/jobs may often have exceeded current Occupational Safety and Health Administration (OSHA) Permissible Exposure Limits (PELs), they did not exceed relevant contemporaneous occupational exposure standards. This analysis provides a better understanding of historical airborne asbestos exposures that bricklayers and other tradesmen experienced during furnace and stove work in the US steel mills.

scholarly journals The Value of BECCS in IAMs: a Review

2019 ◽  
Vol 6 (4) ◽  
pp. 107-115 ◽  
Author(s):  
Alexandre C. Köberle
Keyword(s):  
Carbon Capture ◽  
Energy Use ◽  
Carbon Capture And Storage ◽  
Integrated Assessment Model ◽  
Assessment Model ◽  
Model Structure ◽  
Low Carbon ◽  
Discount Rates ◽  
Value Drivers ◽  
End Use

Abstract Purpose of Review Integrated assessment model (IAM) scenarios consistent with Paris Agreement targets involve large negative emission technologies (NETs), mostly bioenergy with carbon capture and storage (BECCS). Such reliance on BECCS implies IAMs assign it a high value. Past analyses on the value of BECCS in IAMs have not explicitly addressed the role of model structure and assumptions as value drivers. This paper examines the extent to which the value of BECCS in IAMs is enhanced by model structure constraints and assumptions. Recent Findings Predominant use of high discount rates (3.5–5%) means models opt for delayed-action strategies for emissions mitigation that lead to high levels of cumulative net-negative emissions, while lower discount rates lead to reduce reliance on NETs. Until recently in the literature, most models limited NET options to only BECCS and afforestation, but introduction of other CDR options can reduce BECCS deployment. Constraints on grid penetration of variable renewable energy (VRE) is a determining factor on the level of BECCS deployment across models, and more constrained grid penetration of VREs leads to more BECCS in electricity generation. Summary This paper concludes BECCS derives significant value not only from the existing structure of IAMs but also from what is not represented in models and by predominant use of high discount rates. Omissions include NETs other than BECCS and deforestation, low-carbon innovation in end-use technologies, grid resilience to intermittent sources, and energy use in agriculture production. As IAMs increasingly endogenize such constraints, the value of BECCS in resulting scenarios is likely to be dampened.

Infrared Analysis on Pyrolysis Products of Flame Retardant Rigid Polyurethane Foam

2014 ◽  
Vol 1033-1034 ◽  
pp. 900-906
Author(s):  
Ze Jiang Zhang ◽  
Li Jun Li ◽  
Feng Li ◽  
Jin He ◽  
Zi Qiong Gan
Keyword(s):  
Flame Retardant ◽  
Polyurethane Foam ◽  
Magnesium Hydroxide ◽  
Hydrogen Cyanide ◽  
Flame Retardants ◽  
Fire Retardant ◽  
Infrared Analysis ◽  
Antimony Trioxide ◽  
Stretching Vibration ◽  
Flame Retarded

Infrared spectra of the pyrolysis gases of polyurethane foam flame retarded by MPOP, MP, MC, magnesium hydroxide, or antimony trioxide flame retardants was analyzed online by FTIR method. At 600°C, the polyurethane foam flame retarded by MPOP, MP, MC, magnesium hydroxide or antimony trioxide flame retardants released more hydrogen cyanide than the pure polyurethane foam, proved that the MPOP, MP, MC and magnesium hydroxide flame retardants could change the law that the polyurethane released hydrogen cyanide. At 600 °C, the peak of C=O stretching vibration at 1730cm-1did not appear for the flame-retardant polyurethane, indicating that the flame retardants can make the polyurethane rapidly carbonize and the fewer C=O intermediate was produced. The absorbent peaks of the fire-retardant samples at 1604cm-1, 1538 cm-1, 1250 to 1230 cm-1and 1450cm-1implied that the flame retardants could delay the oxidative decomposition of the polyurethane component at 600 °C, so that more components may be carbonized. When increasing the pyrolysis temperature, the perlite would make polyurethane foam release fewer hydrogen cyanide.

Catchability of snow crab (Chionoecetes opilio) by the eastern Bering Sea bottom trawl survey estimated using a catch comparison experiment

2013 ◽  
Vol 70 (12) ◽  
pp. 1699-1708 ◽  
Author(s):  
David A. Somerton ◽  
Kenneth L. Weinberg ◽  
Scott E. Goodman
Keyword(s):  
Experimental Data ◽  
Bering Sea ◽  
Weighted Average ◽  
Assessment Model ◽  
Bottom Trawl ◽  
Snow Crab ◽  
Trawl Survey ◽  
Chionoecetes Opilio ◽  
Bottom Trawl Survey ◽  
Eastern Bering Sea

Catchability of the eastern Bering Sea (EBS) bottom trawl survey for snow crab (Chionoecetes opilio) was estimated from experimental data to provide a constraint on the survey catchability parameters in the stock assessment model. The experiment utilized a second fishing vessel to conduct side-by-side trawling with each of two survey vessels at 92 stations using an experimental trawl assumed to capture all crabs in its path. Trawl efficiency, or the captured proportion of crabs in the trawl path, was estimated for the 83-112 Eastern otter trawl from experimental data using a nonparametric smooth function of carapace width, sediment size, and depth. Survey catchability was then estimated as the catch-weighted average of the predicted trawl efficiency at all 275 survey stations where snow crabs were captured. The fitted model indicated that trawl selectivity was greater in sand than mud and greater in shallow water than deep. At a carapace widths >95 mm, the minimum commercial size limit, the estimated survey catchability of males is considerably less than previously reported.

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