Treands in atmospheric turbidity over India

Annual mean values of the turbidity coefficients at Indian Background Air Pollution Monitoring Network' (BAPMoN) were compared for the periods 1973-1980and 1981-1985. It was found that there is a general increase of turbidity during the latter period at all the stations except at Kodaikanal and Pune, suggesting the effect of anthropogenic sources of pollution. Short term influence of volcanic eruptions were also discernible from the observations at Kodaikanal. Spectral analysis (FFT) at these stations brought out the predominant modes which could be explained on the basis of climatology and aerosol dispersion characteristics. The long term atmospheric turbidity observations (1973-1985) presented in this paper provide reliable data set for assessing the aerosol impact on radiation climate.

Advanced Microparticulate/Nanoparticulate Respirable Dry Powders of a Selective RhoA/Rho Kinase (Rock) Inhibitor for Targeted Pulmonary Inhalation Aerosol Delivery

Pulmonary hypertension (PH) is a progressive disease that eventually leads to heart failure and potentially death for some patients. There are many unique advantages to treating pulmonary diseases directly and non-invasively by inhalation aerosols and dry powder inhalers (DPIs) possess additional unique advantages. There continues to be significant unmet medical needs in the effective treatment of PH that target the underlying mechanisms. To date, there is no FDA-approved DPI indicated for the treatment of PH. Fasudil is a novel RhoA/Rho kinase (ROCK) inhibitor that has shown great potential in effectively treating pulmonary hypertension. This systematic study is the first to report on the design and development of DPI formulations comprised of respirable nanoparticles/microparticles using particle engineering design by advanced spray drying. In addition, comprehensive physicochemical characterization, in vitro aerosol aerosol dispersion performance with different types of human DPI devices, in vitro cell-drug dose response cell viability of different human respiratory cells from distinct lung regions, and in vitro transepithelial electrical resistance (TEER) as air-interface culture (AIC) demonstrated that these innovative DPI fasudil formulations are safe on human lung cells and have high aerosol dispersion performance properties.

Simulation of aerosol dispersion during medical examinations

The main route of transmission of the SARS-CoV2 virus has been shown to be airborne. The objective of this study is to analyze the aerosol dispersion and potential exposure to medical staff within a typical medical examination room during classical airway procedures. The multiphase simulation of the aerosol particles in the airflow is based on a Lagrangian-Eulerian approach. All simulation cases with surgical mask show partially but significantly reduced maximum dispersion distances of the aerosol particles compared to the cases without surgical mask. The simulations have shown that medical examiner are exposed to large amount of aerosol particles, especially during procedures such as laryngoscopy where the examiner's head is directly in front of the patient's face. However, exposure can be drastically reduced if the patient wears a mask which is possible for the most of the procedures studied, such as otoscopy, sonography, or anamnesis.

Effects of surgical masks on aerosol dispersion in professional singing

Background In the CoVID-19 pandemic, singing came into focus as a high-risk activity for the infection with airborne viruses and was therefore forbidden by many governmental administrations. Objective The aim of this study is to investigate the effectiveness of surgical masks regarding the spatial and temporal dispersion of aerosol and droplets during professional singing. Methods Ten professional singers performed a passage of the Ludwig van Beethoven’s “Ode of Joy” in two experimental setups—each with and without surgical masks. First, they sang with previously inhaled vapor of e-cigarettes. The emitted cloud was recorded by three cameras to measure its dispersion dynamics. Secondly, the naturally expelled larger droplets were illuminated by a laser light sheet and recorded by a high-speed camera. Results The exhaled vapor aerosols were decelerated and deflected by the mask and stayed in the singer’s near-field around and above their heads. In contrast, without mask, the aerosols spread widely reaching distances up to 1.3 m. The larger droplets were reduced by up to 86% with a surgical mask worn. Significance The study shows that surgical masks display an effective tool to reduce the range of aerosol dispersion during singing. In combination with an appropriate aeration strategy for aerosol removal, choir singers could be positioned in a more compact assembly without contaminating neighboring singers all singers.

In Situ Measurement of Airborne Particle Concentration in a Real Dental Office: Implications for Disease Transmission

Aerosols generated during dental procedures are one of the most significant routes for infection transmission and are particularly relevant now in the context of COVID-19 pandemic. This study aimed to assess the effectiveness of an indoor air purifier on dental aerosol dispersion in dental offices. The spread and removal of aerosol particles generated from a specific dental operation in a dental office are quantified for a single dental activity in the area near the generation and corner of the office. The effects of the air purifier, door condition, and particle sizes on the spread and removal of particles were investigated. The results show that, in the worst-case scenario, it takes 95 min for 0.5-μm particles to settle and that it takes a shorter time for the larger particles. The air purifier expedited the removal time at least 6.3 times faster than the case with no air purifier in the generation zone. Our results also indicate that particles may be transported from the source to the rest of the room even when the particle concentrations in the generation zone dropped back to the background. Therefore, it is inaccurate to conclude that indoor purifiers help reduce the transmission of COVID-19. Dental offices still need other methods to reduce the transmission of viruses.