Praphulla Chandra Boggarapu

How effective is your face mask?*

*Fit means more than fabric.

Have you wondered how effective your cloth mask is in protecting you from the COVID-19 corona virus? We wondered that too, and this led to our newest research project—studying the effectiveness of cloth face masks. Shahbaz Qureshi, a 2020 UWB Biochemistry graduate, and Praphulla Boggarapu Chandra, postdoctoral researcher, have been working with Dr. Dan Jaffe on testing mask effectiveness. Their research was featured on KIRO 7 news, where Dan Jaffe was interviewed by reporter Jessica Oh.

Shahbaz Qureshi doing mask research — Shahbaz Qureshi adjusts a cloth mask on a mannequin head in an experiment testing the mask’s effectiveness. Photo credit: Marc Studer.

The preliminary research results show that for filtration, fit is more important than the mask material: Tight-fitting masks were twice as efficient in stopping aerosol particles as looser masks. “All masks reduce the particulate—the aerosols you’re putting out in the world and the aerosols you’re breathing in—both ways to some degree,” Jaffe said. “If you wear it properly and you have a tight-fitting mask, it reduces it a lot more.” Dr. Jaffe also plans to present the mask problem to his Quantitative Environmental Analysis class in the upcoming Autumn quarter. “Students will for themselves see: How good is my mask, and how important is the fit?”

Watch the KIRO7 news video on the mask research

2 new papers explore methods for measuring biomass burning pollutants

Research by Jaffe Group postdoctoral scholars Dr. James Laing and Dr. Boggarapu Praphulla Chandra has resulted in two new peer-reviewed publications. Both papers examine methods used for measuring air pollutants from wildfires.

The first paper, “Comparison of filter-based absorption measurements of biomass burning aerosol and background aerosol at the Mt. Bachelor Observatory,” was recently published in Aerosol and Air Quality Research. The authors, Dr. James Laing, Dr. Daniel Jaffe, and Dr. Arthur Sedlacek, III, evaluated the upgraded aethalometer (AE33, Magee Scientific) and the new tricolor absorption photometer (TAP, Brechtel) to assess their effectiveness in measuring wildfire aerosol plumes. These instruments measure light-absorbing organic aerosols, which are emitted primarily in biomass burning. Both instruments were deployed at Mt. Bachelor Observatory (MBO) in central Oregon during the summer of 2016. Each instrument uses a similar methodology (“light extinction through an aerosol-laden filter”), but each has a unique set of corrections necessary to address filter-based bias and other issues. The coauthors found that when using the AE33 manufacturer’s recommended settings, correction factors that are larger than the manufacturer’s recommended factor are needed to calculate accurate absorption coefficients and equivalent black carbon.

Read the full paper.

In the second paper, coauthors Dr. Boggarapu Praphulla Chandra, Dr. Crystal McClure, JoAnne Mulligan, and Dr. Daniel Jaffe evaluated the use of dual-bed thermal desorption (TD) tubes with an auto-sampler to sample volatile organic compounds (VOCs). Their paper, “Optimization of a method for the detection of biomass-burning relevant VOCs in urban areas using thermal desorption gas chromatography mass spectrometry,” appeared in the journal Atmosphere in March. For this study, the authors utilized a portable, custom-made “suitcase” sampler, which they deployed in Boise, ID, during the summer of 2019.

The sampler continuously collected samples of VOCs on the TD tubes for up to six days without the need for continuous on-site monitoring. The tubes were later transferred to the lab for analysis using thermal desorption gas chromatography mass spectrometry (TD-GC-MS) to detect VOCs.

Suitcase thermal desorption VOC auto-sampler 4-2020 — (a) Internal view of the volatile organic compound (VOC) suitcase sampler; (b) Flow diagram of the VOC suitcase sampler; (c) Schematic diagram of the dual-bed TD tubes.

They found that “reactive and short-lived VOCs such as acetonitrile (a specific chemical tracer for biomass burning), acetone, n-pentane, isopentane, benzene, toluene, furan, acrolein, 2-butanone, 2,3-butanedione, methacrolein, 2,5- dimethylfuran, and furfural . . . can be quantified reproducibly with a total uncertainty of ≤30% between the collection and analysis, and with storage times of up to 15 days.”

Their research demonstrates the applicability of this flexible method for ambient VOC speciation and determining the influence of forest fire smoke. This sampling method offers a practical alternative for urban air quality monitoring sites because its portability does not require the installation of a complex and expensive instrument and its auto-sampling technique does not require continuous on-site monitoring.

Read the full paper.

Introducing our newest postdoc research associate

In November, Dr. Praphulla Chandra Boggarapu joined the Jaffe Group as a postdoc research associate. Praphulla grew up in Vizag, Andhra Pradesh, India, and is new to the Seattle area. He received his Ph.D. from the Indian Institute of Science Education and Research (IISER) in Mohali, India. His dissertation was titled “Measurements of reactive Volatile Organic Compounds (VOCs) and their emissions in agricultural and urban atmospheric environments of the Indo-Gangetic Plain (IGP)”

Praphulla’s research work in the Jaffe Group will focus on the impact of biomass burning. In particular, he will employ his GC-MS expertise to analyze wildfire emissions.

In his free time, he enjoys Veda chanting, yoga, and playing chess. We are excited to have Praphulla on the team and wish him a quick adjustment to our winter weather!