Introduction to Bioaerosols Assessment and Control, 2nd Edition

Risk Assessment Assessment for the Presence of Bioaerosols Sampling Purpose/ Necessity Interpretation Controls Ventilation Other Control

E-Cigarettes: A Hazy Hazard

• Electronic cigarettes (e-cigarettes or e-cigs) are battery-powered devices that deliver vaporized nicotine and other substances, such as flavorings, to users without smoke or combustion. They are commonly marketed as smoking cessation tools and, as such, are promoted as being a healthier alternative to smoking. • A common misperception is that that e-cigarettes only release water vapor. In reality, though, these devices release nicotine and other chemicals in a vapor form that can expose both the user (a.k.a., the vaper), as well as those in the immediate vicinity, to those contaminants. While the health risks of e-cigarettes compared to regular cigarette smoking is greatly reduced, many toxic compounds are still present. • The rapid increase in use of electronic cigarettes has generated a potential concern for indoor air quality in that there is still limited data on potential exposures and human health risks for users, or for others through second- and third-hand exposures

Recovering from COVID-19 Building Closures: Guidance Document

While the country comes to terms with the inevitable impact that SARS-CoV-2, the virus that causes COVID-19, will have on our lives and communities, public health authorities remain focused on breaking the chain of transmission. Managing the risk has resulted in widespread closures of businesses, schools, universities, resorts, and other facilities deemed “non-essential.” Practically speaking, this means closing buildings and ceasing operations. For building owners and operators, this poses a significant challenge to protect their assets and to ensure they are ready to reoccupy once the pandemic subsides

The Value of IAQ: A Review of the Scientific Evidence Supporting the Benefits of Investing in Better Indoor Air Quality

Other studies have examined how ventilation rates, combined with the presence of pollutant sources, can affect productivity. These studies provide evidence that increased ventilation, including increases above common guidance levels such as ASHRAE’s ventilation standards, improve occupant productivity. Increased occupant control over ventilation has also been shown to improve productivity. Higher indoor carbon dioxide (CO2) levels have been directly associated with impaired work performance and increased health symptoms. Historically, it was believed that these associations exist only because higher indoor CO2 concentrations, resulting from lower outdoor air ventilation rates, are also correlated with higher levels of other indoor-generated pollutants that directly cause the adverse effects. More recent studies, however, have found that CO2 itself, even at levels previously considered acceptable, may have adverse effects. Considering the benefits and demonstrated return on investment, building owners and operators should consider proactive methods of improving IAQ. Established strategies and guidelines are readily available to help identify and implement IAQ-related improvements. These include recognizing and addressing potential and real IAQ issues during the design, construction, renovation, and ongoing maintenance of buildings. Research has found that the benefits of IAQ improvement far outweigh the costs, with estimates of 3–6 times returns for increased ventilation, 8 times returns for increased filtration, and up to 60 times returns when all improvements and related benefits are combined. Collectively, the scientific literature demonstrates that improved workplace productivity and reduced absenteeism from improved IAQ have been shown to provide substantial financial benefits, with the benefits often greatly outweighing the associated costs

Rapid evolution of aerosol particles and their optical properties downwind of wildfires in the western US

During the first phase of the Biomass Burn Operational Project (BBOP) field campaign, conducted in the Pacific Northwest, the DOE G-1 aircraft was used to follow the time evolution of wildfire smoke from near the point of emission to locations 2-3.5 h downwind. In nine flights we made repeated transects of wildfire plumes at varying downwind distances and could thereby follow the plume\u27s time evolution. On average there was little change in dilution-normalized aerosol mass concentration as a function of downwind distance. This consistency hides a dynamic system in which primary aerosol particles are evaporating and secondary ones condensing. Organic aerosol is oxidized as a result. On all transects more than 90 % of aerosol is organic. In freshly emitted smoke aerosol, NH+4 is approximately equivalent to NO3. After 2 h of daytime aging, NH+4 increased and is approximately equivalent to the sum of Cl, SO24, and NO3. Particle size increased with downwind distance, causing particles to be more efficient scatters. Averaged over nine flights, mass scattering efficiency (MSE) increased in ∼ 2 h by 56 % and doubled in one flight. Mechanisms for redistributing mass from small to large particles are discussed. Coagulation is effective at moving aerosol from the Aitken to accumulation modes but yields only a minor increase in MSE. As absorption remained nearly constant with age, the time evolution of single scatter albedo was controlled by age-dependent scattering. Near-fire aerosol had a single scatter albedo (SSA) of 0.8-0.9. After 1 to 2 h of aging SSAs were typically 0.9 and greater. Assuming global-average surface and atmospheric conditions, the observed age dependence in SSA would change the direct radiative effect of a wildfire plume from near zero near the fire to a cooling effect downwind

Prospectus, September 14, 1977

TWO VIE FOR VEEP POST: STUDENT GOVERNMENT ELECTIONS TODAY; Elections scheduled today and tomorrow; District 505 entitled to minimum credit grants; Activities postponed; Unopposed; Shiloh\u27s and Sonshine Circle to perform; Survival of democratic society topic at forum; Vets must go by book; \u27Self Defense\u27 is under attack; Youngest brew master is nun; Warners, women battle over \u27Jump On It\u27; Male prostitute makes history; News From \u27Her Say\u27: Ten women earn wings; UAW asks Congress for maternity benefits \u27as soon as possible\u27; Career Awareness Course for women Wednesday eve.; Instructors earn high grades from PC students; Back orders on home insulation cause woes; Blowing of the shofar means Rosh Hashanah, start of 5,738 New Year; Springfield news: senior citizens, equal language; The gas man cometh...; Holograph exhibit at PC tomorrow; Letting out some Slack...: Answers for queries on PC; Chicago painter displays at KCPA; Prospectus Pigskin Preview: Cobra Grid Schedule, Parkland Roster, Fight on Cobras; Alaskan wilderness is summer home to Basler; Parkland Learning Laboratory: Early help available to students; Stu-Go explores check cashing for PC people; PC music groups have many openings; Jumers: German touch; \u27Elite\u27 women to get public house; Home care topic to be presented; Classifieds; X-country opens Saturday; Spikettes look good; Sports shorts; Bio instructor Cox wins Fast Freddy; Intramural sign up closing; The continuing battle for Number 1; Parkland to host nationalshttps://spark.parkland.edu/prospectus_1977/1013/thumbnail.jp

Influence of urban pollution on the production of organic particulate matter from isoprene epoxydiols in central Amazonia

The atmospheric chemistry of isoprene contributes to the production of a substantial mass fraction of the particulate matter (PM) over tropical forests. Isoprene epoxydiols (IEPOX) produced in the gas phase by the oxidation of isoprene under HO2-dominant conditions are subsequently taken up by particles, thereby leading to production of secondary organic PM. The present study investigates possible perturbations to this pathway by urban pollution. The measurement site in central Amazonia was located 4 to 6 h downwind of Manaus, Brazil. Measurements took place from February through March 2014 of the wet season, as part of the GoAmazon2014/5 experiment. Mass spectra of organic PM collected with an Aerodyne Aerosol Mass Spectrometer were analyzed by positive-matrix factorization. One resolved statistical factor (IEPOX-SOA factor) was associated with PM production by the IEPOX pathway. The IEPOX-SOA factor loadings correlated with independently measured mass concentrations of tracers of IEPOX-derived PM, namely C5-alkene triols and 2-methyltetrols (R = 0. 96 and 0.78, respectively). The factor loading, as well as the ratio f of the loading to organic PM mass concentration, decreased under polluted compared to background conditions. For an increase in NOy concentration from 0.5 to 2 ppb, the factor loading and f decreased by two to three fold. Overall, sulfate concentration explained 37 % of the variability in the factor loading. After segregation of factor loading into subsets based on NOy concentration, the sulfate concentration explained up to 75 % of the variability. Considering both factors, the data sets show that the suppressing effects of increased NO concentrations dominated over the enhancing effects of higher sulfate concentrations. The pollution from Manaus elevated NOy concentrations more significantly than sulfate concentrations relative to background conditions. In this light, increased emissions of nitrogen oxides, as anticipated for some scenarios of Amazonian economic development, could significantly alter pathways of PM production that presently prevail over the tropical forest, implying changes to air quality and regional climate.</html

Introduction to Bioaerosols Assessment and Control, 2nd Edition

Risk Assessment Assessment for the Presence of Bioaerosols Sampling Purpose/ Necessity Interpretation Controls Ventilation Other Control

Chronicles of Oklahoma

Article narrates the experiences of John L. Springston, an 83-year-old Cherokee man, as he lived in within Spavinaw, a town in Oklahoma, throughout his lifetime. His story details the history of the town and its hidden secrets

E-Cigarettes: A Hazy Hazard

• Electronic cigarettes (e-cigarettes or e-cigs) are battery-powered devices that deliver vaporized nicotine and other substances, such as flavorings, to users without smoke or combustion. They are commonly marketed as smoking cessation tools and, as such, are promoted as being a healthier alternative to smoking. • A common misperception is that that e-cigarettes only release water vapor. In reality, though, these devices release nicotine and other chemicals in a vapor form that can expose both the user (a.k.a., the vaper), as well as those in the immediate vicinity, to those contaminants. While the health risks of e-cigarettes compared to regular cigarette smoking is greatly reduced, many toxic compounds are still present. • The rapid increase in use of electronic cigarettes has generated a potential concern for indoor air quality in that there is still limited data on potential exposures and human health risks for users, or for others through second- and third-hand exposures