Evaluation of Various IVC Systems According to Mouse Reproductive Performance and Husbandry and Environmental Parameters

IVC systems are marketed for improving the health and management of mouse colonies. The current study compared mouse reproductive performance and husbandry and environmental parameters among 3 high-density (HD) IVC rack systems (RS1, RS2, and RS3), which were present in separate but comparable rooms. Three breeding trios each of Swiss Webster (CFW) and BALB/c mice were placed in each rack (n = 36 female, n = 18 male). Reproductive indices were measured for 3 breeding cycles over 2 generations; indices included time to parturition, litter size and pup weight, survivability, and interbirth interval. Over 18 wk, personnel used scoring systems to evaluate each RS daily to every other week according to cage dirtiness, need for spot changing, ease of cage changing, daily health checks, and cage wash processing. Macroenvironmental parameters (temperature, relative humidity, noise, total particulate matter) were measured weekly over 14 wks. Microenvironmental parameters (temperature, relative humidity, NH3, CO2, O2) of 2 cages each of male and female CFW mice (4 mice/cage) on each RS were measured at 6 time points over 2 wks. RS1 had significantly smaller mean litter sizes of CFW mice (mean ± 1 SD, 6.5 ± 2.9 pups) as compared with both RS2 (9.5 ± 1.7 pups) and RS3 (9.3 ± 3.8 pups). RS1 scored as beingsignificantly easier to process through the cage wash. RS2 had significantly lower room noise levels (46.0 ± 5.0 dBA) but higher humidity (58.6% ± 8.9%) as compared with both RS1 (43.7% ± 9.9%) and RS3 (46.0% ± 12.0%) over the 2-wk cycle, particularly at 8 and 12 d after cage change. In conclusion, in terms of mouse reproductive performance and husbandry and environmental parameters, each system had at least 1 advantage over the other 2. Therefore, various factors should be considered when choosing an IVC system for mice.

Proposed Standard Test Protocols and Outcome Measures for Quantitative Comparison of Emissions from Electronic Nicotine Delivery Systems

This study introduces and demonstrates a comprehensive, accurate, unbiased approach to robust quantitative comparison of Electronic Nicotine Delivery Systems (ENDS) appropriate for establishing substantial equivalence (or lack thereof) between tobacco products. The approach is demonstrated across a family of thirteen pen- and pod-style ENDS products. Methods employed consist of formulating a robust emissions surface regression model, quantifying the empirical accuracy of the model as applied to each product, evaluating relationships between product design characteristics and maximum emissions characteristics, and presenting results in formats useful to researchers, regulators, and consumers. Results provide a response surface to characterize emissions (total particulate matter and constituents thereof) from each ENDS appropriate for use in a computer model and for conducting quantitative exposure comparisons between products. Results demonstrate that emissions vary as a function of puff duration, flow rate, E-Liquid composition, and device operating power. Further, results indicate that regulating design characteristics of ENDS devices and consumables may not achieve desired public health outcomes; it is more effective to regulate maximum permissible emissions directly. Three emissions outcome measures (yield per puff, mass concentration and constituent mass ratio) are recommended for adoption as standard quantities for reporting by manufacturers and research laboratories. The approach provides a means of (a) quantifying and comparing maximal emissions from ENDS products spanning their entire operating envelope, (b) comparative evaluation of ENDS devices and consumable design characteristics, and (c) establishing comparative equivalence of maximal emissions from ENDS. A consumer-oriented product emissions dashboard is proposed for comparative evaluation of ENDS exposure potential. Maximum achievable power dissipated in the coil of ENDS is identified as a potentially effective regulatory parameter.

Cigarette Smoke Extract Produces Superoxide in Aqueous Media by Reacting with Bicarbonate

The toxicity of cigarette smoke (CS) is largely attributed to its ability to generate reactive oxygen species (ROS). Reportedly, CS generates superoxide in cell culture systems by stimulating the cells to produce superoxide and through direct chemical reactions with components of the culture media. In this study, we investigated CS-induced superoxide formation in biocompatible aqueous media and its characteristics. Cigarette smoke extract (CSE) and total particulate matter (TPM) were prepared from the mainstream smoke of 3R4F reference cigarettes. CSE and TPM generated superoxide in Hank’s balanced salt solution (HBSS), Dulbecco’s modified Eagle media (DMEM), and blood plasma, but not in distilled water and phosphate-buffered saline. Each constituent of HBSS in solution was tested, and bicarbonate was found to be responsible for the superoxide generation. More than half of the superoxide formation was abolished by pretreating CSE or TPM with peroxidase, indicating that the substrates of peroxidase, presumably peroxides and peroxy acids, mainly contributed to the superoxide production. In conclusion, the presence of bicarbonate in experimental conditions should be considered carefully in studies of the biological activity of CS. Furthermore, the local amount of bicarbonate in exposed tissues may be a determinant of tissue sensitivity to oxidative damage by CS.

The Effects of Cigarette Filter Ventilation on Delivery and Retention of Organic Acids

Summary A method for simultaneous identification and quantitative determination of 30 organic acids was established. The smoke yields and filter retentions of organic acids and routine smoke components, total particulate matter (TPM), nicotine-free dry particulate matter (NFDPM), nicotine and carbon monoxide (CO) at different filter ventilation levels were determined under both International Organization for Standardization (ISO) and Health Canadian Intense (HCI) smoking regimes. As a result of smoke dilution during filter ventilation, the yields of all organic acids were reduced in mainstream cigarette smoke. The spatial distribution pattern of the concentration of each organic acid in the filter was investigated at different ventilation levels and their filter retention determined. On one hand, the concentration of organic acids with a lower boiling point (BP) and lower molecular weight (MW) was relatively higher at the smoking end and the periphery part of the filter and spatial concentration distributions within the filter were significantly affected by smoke diffusion. On the other hand, those acids with high BPs and high MW were mainly distributed at the tobacco rod end and central part of the filter and spatial concentration distributions were only slightly influenced by their smoke diffusion within the filter whilst air compression around the filter vents also led to less change. This way, different acids in mainstream cigarette smoke were reduced to different extents which can also influence the acid-base equilibrium and sensory quality of the smoke. Compared with ISO smoking regime, the vent blocking and more intense smoking HCI regime led to different extents of yield increase for each of the studied acids. The effect of filter ventilation in the HCI smoking regime was not investigated, as the HCI smoking regime requires blocked ventilation holes. [Contrib. Tob. Nicotine Res. 30 (2021) 199–211]

Comparative analysis of the emissions of carbon dioxide and toxic substances emitted by vehicles with ICE compared to the equivalent emissions of BEV

In the article were compared the vehicles (by pairing) the vehicles on the basis of selected criteria considering vehicles’: weight, length, wheel width, maximum output and acceleration time. The article was carried out by analysing the available source materials and specific energy mix based on coal. The emission of air pollutants (exhaustive) was estimated using the mathematical calculation. In order to carry out the analysis, the data provided by the manufacturers of the considered cars were used, concerning fuel consumption by the cars equipped with the internal combustion engines or electricity consumption in the case of cars with equipped with electric motors. The air pollutants that were taken into consideration: carbon monoxide, nitrogen oxides, sulphur dioxide, carbon dioxide, and total particulate matter. Apart from the exhaustive emissions, the total particular matter emissions from the tyre and brake wear and road abrasion is also included. The pollutant emission was estimated on the basis of emission factors using the average mileage characterizing for driving in European conditions.

Fuel Improvement Measures for Particulate Matter Emission Reduction during Corn Cob Combustion

Fuel-related measures and modernization of small-scale combustion units has become the focus of attention in the renewable heat generation sector, as a means to promote local biomass utilization and fuel-flexibility while meeting strict environmental legislative requirements. With the aim to mitigate total particulate matter emissions and ash-associated problems characteristic of crop residue combustion, (1) corn cob pellets (with and without kaolin and binder) as well as (2) fuel blends with wood pellets were combusted in a pellet oven under full load. Results show that additivation or fuel blending (e.g., 50 wt. % wood and 50 wt. % corn cob pellets) reduce total particulate and CO-emissions by 48 to 60 wt. % and 64 to 89 wt. %, respectively, in comparison to baseline emissions from non-additivized corn cob pellets. Kaolin prevented sintering of corn cob ash. However, considerable grate ash entrainment was observed. TPM consists of a “primary network”—polyhedral and spherical particles approximately 1 μm in diameter (mainly KCl), and a “secondary network” built on top of the primary network, consisting of square-prism-shaped particles of approximately 200 nm in diameter. KCl and K2SO4 are main compounds in particles from corn cob and wood pellet combustion, respectively. Effective measures demonstrated within this study should be complemented with low-cost coarse ash removal systems.