Influence of microstructure and physical characteristics in the performance of non-professional masks sold in São Paulo.

Objectives: This study evaluates the performance of eight non-professional face masks sold in São Paulo, Brazil, to prevent aerial transmission of the SARS-CoV-2.

Study Design: This was a case report with comparative testing.

Methods: The masks manufactured with different materials and designs were quantified according to their performance to prevent COVID-19 using two indicators: filtration efficiency (FE) and differential pressure.

Decontamination and re-use of surgical masks and respirators during the COVID-19 pandemic.

Objectives: The coronavirus disease 2019 pandemic increased global demand for personal protective equipment (PPE) and resulted in shortages. The study evaluated the re-use of surgical masks and respirators by analysing their performance and safety before and after reprocessing using the following methods: oven, thermal drying, autoclave, and hydrogen peroxide plasma vapour.

Methods: In total, 45 surgical masks and 69 respirators were decontaminated.

Aerosol properties in the atmosphere of Natal/Brazil measured by an AERONET Sun-photometer.

We analyzed data measured by a Sun-photometer of the RIMA-AERONET network with the purpose to characterize the aerosol properties in the atmosphere over Natal, state capital of Rio Grande do Norte, at the coast of Northeast Brazil. Aerosol Optical Depth, Ångström Exponent, Volume Size Distribution, Single Scattering Albedo, Complex Refractive Index, Asymmetry Factor, and Precipitable Water were analyzed from August 2017 to March 2018. In addition, MODIS and CALIOP observations, local Lidar measurements, and modeled backward trajectories were analyzed in a case study on February 9, 2018, that consistently confirmed the identification of a persistent aerosol layer below 4 km agl.