Pedro Souza's Avatar

Pedro Souza

@pedroafs.bsky.social

Atmospheric/Analytical Chemist, Brazilian and environmentalist βš›οΈπŸ‡§πŸ‡·πŸŒ± Figuring out how oxidants and photochemistry shape indoor air quality PhD candidate at USask πŸ‡¨πŸ‡¦

151 Followers  |  173 Following  |  18 Posts  |  Joined: 31.01.2024  |  2.9435

Latest posts by pedroafs.bsky.social on Bluesky

Folks - check out this new review, led by the amazing @ericamhartmann.bsky.social: Ten questions concerning indoor dust.

12.11.2025 17:13 β€” πŸ‘ 7    πŸ” 3    πŸ’¬ 1    πŸ“Œ 1
Comic. Confusion matrix showing renditions of different combinations, colored yellow, tan, or gray. [Air: gamma rays Y, neutrons Y, alpha particles G, light Y, sound Y, heat Y, swords Y, toxic dust Y, radio Y, sharks G] [Lead: gamma rays G, neutrons T, alpha particles G, light G, Sound Y, heat Y, swords G, toxic dust T, radio G, sharks G] [Water: gamma rays T, neutrons G, alpha particles G, light T, sound Y, heat Y, swords Y, toxic dust Y, radio G, sharks Y] [Vacuum: gamma rays Y, neutrons Y, alpha particles Y, light Y, sound G, heat T, swords Y, toxic dust Y, radio Y, sharks G] [Oven mitts: gamma rays Y, neutrons Y, alpha particles G, light G, sound T, heat G, swords Y, toxic dust Y, radio Y, sharks Y] [Armor: gamma rays Y, neutrons Y, alpha particles G, light G, sound Y, heat Y, swords G, toxic dust Y, radio G, sharks T] [Biohazard suit: gamma rays Y, neutrons Y, alpha particles G, light G, sound Y, heat Y, swords Y, toxic dust G, radio Y, sharks Y] [Faraday cage: gamma rays Y, neutrons Y, alpha particles Y, light Y, sound Y, heat Y, swords Y, toxic dust Y, radio G, sharks Y] [Shark cage: gamma rays Y, neutrons Y, alpha particles Y, light Y, sound Y, heat Y, swords Y, toxic dust Y, radio Y, sharks G]

Comic. Confusion matrix showing renditions of different combinations, colored yellow, tan, or gray. [Air: gamma rays Y, neutrons Y, alpha particles G, light Y, sound Y, heat Y, swords Y, toxic dust Y, radio Y, sharks G] [Lead: gamma rays G, neutrons T, alpha particles G, light G, Sound Y, heat Y, swords G, toxic dust T, radio G, sharks G] [Water: gamma rays T, neutrons G, alpha particles G, light T, sound Y, heat Y, swords Y, toxic dust Y, radio G, sharks Y] [Vacuum: gamma rays Y, neutrons Y, alpha particles Y, light Y, sound G, heat T, swords Y, toxic dust Y, radio Y, sharks G] [Oven mitts: gamma rays Y, neutrons Y, alpha particles G, light G, sound T, heat G, swords Y, toxic dust Y, radio Y, sharks Y] [Armor: gamma rays Y, neutrons Y, alpha particles G, light G, sound Y, heat Y, swords G, toxic dust Y, radio G, sharks T] [Biohazard suit: gamma rays Y, neutrons Y, alpha particles G, light G, sound Y, heat Y, swords Y, toxic dust G, radio Y, sharks Y] [Faraday cage: gamma rays Y, neutrons Y, alpha particles Y, light Y, sound Y, heat Y, swords Y, toxic dust Y, radio G, sharks Y] [Shark cage: gamma rays Y, neutrons Y, alpha particles Y, light Y, sound Y, heat Y, swords Y, toxic dust Y, radio Y, sharks G]

Shielding Chart

xkcd.com/3158/

23.10.2025 20:10 β€” πŸ‘ 4404    πŸ” 921    πŸ’¬ 55    πŸ“Œ 41
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This year, the ozone hole presented an early development, reaching a larger-than-average area mid-September. On #WorldOzoneDay, #CopernicusAtmosphere continues to provide tools for everyone to monitor the health of our planet.

16.09.2025 12:50 β€” πŸ‘ 106    πŸ” 46    πŸ’¬ 3    πŸ“Œ 2

This is great. An EPA activity book for elementary school kids on air cleaning:

www.epa.gov/system/files...

26.08.2025 15:06 β€” πŸ‘ 23    πŸ” 12    πŸ’¬ 0    πŸ“Œ 2
This graphic describes chemical reactions triggered by ultraviolet light from the sun. These reactions include those that break down plastics, aid the production of vitamin D, cause skin burns from the sap and juices of some plants, decompose swimming pool chlorination, and form components of brown smog compounds.

This graphic describes chemical reactions triggered by ultraviolet light from the sun. These reactions include those that break down plastics, aid the production of vitamin D, cause skin burns from the sap and juices of some plants, decompose swimming pool chlorination, and form components of brown smog compounds.

This edition of #PeriodicGraphics highlights how ultraviolet light (UV) from the sun triggers chemical reactions, such as those that break down plastics and aid the production of vitamin D. cen.acs.org/physical-che...

#chemsky πŸ§ͺ

26.08.2025 16:16 β€” πŸ‘ 11    πŸ” 4    πŸ’¬ 0    πŸ“Œ 1
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Postdoctoral Researcher in Atmospheric Chemistry

Are you interested in biosphere-atmosphere interactions, global modeling, and living in Zurich? If so, this postdoc position might be for you! Please share with any interested colleagues: jobs.ethz.ch/job/view/JOP...

25.08.2025 13:57 β€” πŸ‘ 25    πŸ” 22    πŸ’¬ 1    πŸ“Œ 1

Does your bedroom have enough ventilation?

www.tandfonline.com/doi/pdf/10.1...

01.08.2025 13:47 β€” πŸ‘ 3    πŸ” 2    πŸ’¬ 0    πŸ“Œ 0
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Theoretical Mapping of the Gas-Phase Ozonolysis of Ξ±-Pinene: Formation of First-Generation Products under Different Atmospheric Conditions Ozonolysis of Ξ±-pinene is a significant and well-established source of atmospheric secondary organic aerosol (SOA), which plays a pivotal role in climate, air quality, and human health. The products of Ξ±-pinene ozonolysis measured experimentally are typically characterized by only their molecular formulas, while their structures and formation mechanisms often remain unclear. In this work, we theoretically map the oxidation pathways, structures, and formation time scales of the major first-generation products formed from Ξ±-pinene ozonolysis by calculating the H-shift and bond-scission reaction rate coefficients of the peroxy (RO2) and alkoxy (RO) radicals that arise under atmospheric conditions with different RO2 bimolecular reaction rates (kbi): polluted (kbi > 0.2 s–1), moderate (0.2 s–1 > kbi > 0.01 s–1), and pristine (kbi β‰ˆ 0.01 s–1). In polluted environments, almost no RO2 unimolecular reactions are of importance and ozonolysis leads to nitrates and small fragmented products. By contrast, in moderate to pristine atmospheres, C10 highly oxygenated organic molecules (HOMs) with up to 12 oxygen atoms can form from either purely unimolecular or a combination of unimolecular and bimolecular reactions. Our results suggest that explicit chemical mechanisms of Ξ±-pinene ozonolysis used ubiquitously in the literature require significant revision in their treatment of unimolecular-isomerization and stereoisomer-specific reactions.

Excited to share our new paper, out today in ACS ES&T Air! Using theory, we map the pathways of Ξ±-pinene ozonolysis leading to first-generation products under different atmospheric conditions.

Co-authors: Jing Chen (lead), @atmostaj.bsky.social, and Henrik Kjaergaard.

@uwatmossci.bsky.social
(1/2)

21.07.2025 16:41 β€” πŸ‘ 6    πŸ” 3    πŸ’¬ 1    πŸ“Œ 0
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Wildfire smoke linked to early deaths A recent study estimates that more than 50,000 adults died prematurely in California over 11 years due to exposure to wildfire smoke

Wildfire smoke linked to early deaths: A recent study estimates that more than 50,000 adults died prematurely in California over 11 years due to exposure to wildfire smoke. cen.acs.org/environment/...

05.06.2025 12:25 β€” πŸ‘ 1    πŸ” 1    πŸ’¬ 0    πŸ“Œ 1
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Particulate Matter and Total Volatile Organic Compound Emissions Following Surface Cleaning: Comparison of Cleaning Agents and Locations Cleaning activities are essential for maintaining hygiene in indoor environments but can significantly influence indoor air quality (IAQ). We investigated emissions of volatile organic compounds (VOCs...

Ever wonder how cleaning affects #IndoorAirQuality?
Our latest work demonstrates that emissions go beyond the active ingredient, with other compounds contributing to #AirPollution.
This is a very neat story with lots of interesting science, hope you enjoy! #ChemSky

pubs.acs.org/doi/10.1021/...

03.06.2025 11:53 β€” πŸ‘ 2    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0
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Exhaled aerosol particles (1-5 um) create a wake behind people walking down hallways. Cool CFD simulations with implications for hospital corridors.

If only this article was out in 2019....

www.sciencedirect.com/science/arti...

02.06.2025 11:57 β€” πŸ‘ 134    πŸ” 56    πŸ’¬ 9    πŸ“Œ 3

RIP Pepe Mujica. He was a true symbol for Latin America!

Among his famous philosophical beliefs, I will forever remember β€œeverything that one purchases, one pays with the spent time to earn the money” and β€œwe are free when we spend time with things that motivate us”.

Do what you love, folks! β™₯️

14.05.2025 21:36 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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Gas stoves nearly double children’s cancer risk, Stanford study finds Stanford study finds gas stoves emit benzene, nearly doubling cancer risk in children β€” especially in homes with poor ventilation.

Funny how breathing combustion byproducts causes all kinds of harm.

www.sfchronicle.com/health/artic...

10.05.2025 00:13 β€” πŸ‘ 106    πŸ” 45    πŸ’¬ 4    πŸ“Œ 2

I just heard the disappointing news that a @nationalacademies.org study on far UV to reduce transmission of respiratory infections was canceled.

www.nationalacademies.org/our-work/cli...

/1

24.04.2025 18:44 β€” πŸ‘ 127    πŸ” 47    πŸ’¬ 5    πŸ“Œ 5
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Environmental Health Works (#EHWorks) - YouTube The air we breathe, water we drink, food we eat, and where we live, work, and play are all crucial determinants of our health and the health of our families....

A belated earth day to all! Sharing a channel of short videos discussing the importance of environmental health research and keeping the planet and ourselves healthy: www.youtube.com/playlist?lis...

23.04.2025 12:36 β€” πŸ‘ 7    πŸ” 2    πŸ’¬ 1    πŸ“Œ 0
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The role of carbon dioxide in airborne disease transmission: a hidden key to safer indoor spaces The concentration of CO2 in the air directly affects how long a virus remains infectious.

Henry Oswin and I had an article published by
@uk.theconversation.com . In it, we discuss the role of CO2 in airborne disease transmission.

Henry was the PhD student on the project, who has since graduated and is now working with Lidia Morawska down under.

theconversation.com/the-role-of-...

16.04.2025 13:02 β€” πŸ‘ 87    πŸ” 48    πŸ’¬ 10    πŸ“Œ 5
Three men (2 with glasses, all with black hair) stand in a garage, staring in contemplation at computer screens that display science stuff. Photo.

Three men (2 with glasses, all with black hair) stand in a garage, staring in contemplation at computer screens that display science stuff. Photo.

We're getting some garage work done. (Or, at least, that's where we're putting our instruments.)
#IndoorChem

14.04.2025 22:58 β€” πŸ‘ 8    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0
Researcher / Senior Researcher – Blueprint Biosecurity Blueprint Biosecurity is building an interdisciplinary technical team that translates academic and industry research into actionable plans to prevent and suppress future pandemics.

Multiple Researcher / Senior Researcher roles at Blueprint Biosecurity: translate research into plans to prevent future pandemics. Produce publications, provide technical advice to our program teams, and inform our pandemic prevention strategies

blueprintbiosecurity.org/jobs/researc...

10.04.2025 23:19 β€” πŸ‘ 4    πŸ” 3    πŸ’¬ 0    πŸ“Œ 0
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They're bad at data analysis because they didn't use a formula with enough superfluous Greek letters

04.04.2025 08:18 β€” πŸ‘ 30    πŸ” 9    πŸ’¬ 1    πŸ“Œ 0

Thanks Dave!

25.03.2025 04:40 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

#ACSSpring2025
In the afternoon we have a wonderful set of talks on both indoor and outdoor chemistry. Come hear Sally Ng, @pedroafs.bsky.social, @vbarber.bsky.social, Celine Toubin, @mvermeuel.bsky.social, @sc-k.bsky.social talk about their research after lunch!!

25.03.2025 04:29 β€” πŸ‘ 1    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0
Promo image for the ES&T Air special symposium: "showcasing emerging science in atmospheric chemistry"

Promo image for the ES&T Air special symposium: "showcasing emerging science in atmospheric chemistry"

#ACSSpring2025 Very excited for our first set of talks tomorrow morning!

We have invited talks by Franz Geiger, @atmosyz.bsky.social, Haofei Zhang, Kevin Wilson, Anthony Carrasquillo, and Marcelo Guzman.

Come here about Atmospheric Multiphase Chemistry in the Marriott Grand Ballroom: Section 2!!

25.03.2025 03:58 β€” πŸ‘ 14    πŸ” 3    πŸ’¬ 1    πŸ“Œ 1
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Excited to see so many interesting studies and to connect with awesome people!
Tomorrow, I am presenting my work on how both photo and chemical disinfection can deeply increase radical concentration indoors.
It will be at 2:30 pm at Marriott Hotel Section 2, everyone is invited to attend!!

25.03.2025 00:01 β€” πŸ‘ 8    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0
The Trump administration’s attacks on scientific funding, restrictions on Federal scientist activities, and 
indiscriminate firing have caused chaos, panic, and harm.

We need *specific* examples of harms caused 
by these policies to include in an open letter. 
Grants cut, projects cancelled, jobs lost.

Feel free to send news stories, blog posts, or social media posts that mention these, as well as original contributions. 

Please send to WhySharksMatter @ gmail or DM me

The Trump administration’s attacks on scientific funding, restrictions on Federal scientist activities, and indiscriminate firing have caused chaos, panic, and harm. We need *specific* examples of harms caused by these policies to include in an open letter. Grants cut, projects cancelled, jobs lost. Feel free to send news stories, blog posts, or social media posts that mention these, as well as original contributions. Please send to WhySharksMatter @ gmail or DM me

Science (and science policy, and conservation) friends, I need your help!

We are collecting *specific, clear* examples of harms caused by the Trump administration's attacks on science, to be included in an open letter.

Can be links to news stories/social media posts. πŸ§ͺπŸ¦‘πŸŒŽ #SciComm #SciPol

21.02.2025 13:59 β€” πŸ‘ 416    πŸ” 337    πŸ’¬ 25    πŸ“Œ 9
Database | ASCENT

Given the #Fires in #LosAngeles, the #ASCENT network led by Sally Ng (GaTech) is making preliminary real-time PM2.5 concentration and composition data from its 3 sites in the LA area available to the public.

ascent.research.gatech.edu/database

21.01.2025 13:32 β€” πŸ‘ 33    πŸ” 15    πŸ’¬ 1    πŸ“Œ 0
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Air pollution and brain damage: what the science says Epidemiological studies have linked dirty air to dementia and other brain disorders. Now researchers are trying to determine how pollutants do their damage, and how much harm they cause.

#MedskyπŸ§ͺ #IDsky #episky #Neurosky #immunosky #pedsky #publichealth Epidemiological studies have linked dirty air to #dementia & other 🧠 disorders. Now researchers are trying to determine how pollutants do their damage & how much harm they cause to the young 🧠

www.nature.com/articles/d41...

18.01.2025 20:09 β€” πŸ‘ 38    πŸ” 10    πŸ’¬ 2    πŸ“Œ 2
Ridgeline chart showing the distribution of global daily air temperature differences from the pre-industrial reference period (1850-1900), for every year between 1940 and 2024. Each individual year resembles a hill, shaded in a darker shade of red and further to the right for warmer years. The trend is clearly towards warmer years, with 2024 standing out as first year above 1.5C.

Ridgeline chart showing the distribution of global daily air temperature differences from the pre-industrial reference period (1850-1900), for every year between 1940 and 2024. Each individual year resembles a hill, shaded in a darker shade of red and further to the right for warmer years. The trend is clearly towards warmer years, with 2024 standing out as first year above 1.5C.

NEW: 2024 has just been confirmed as the warmest year on record, and the first to breach the 1.5C threshold.

We used a ridgeline (Joy Division inspired) chart to visualise daily temperature anomalies since 1940.

2024 clearly stands out with 100% of its days above 1.3C and 75% above 1.5C.

10.01.2025 08:04 β€” πŸ‘ 5918    πŸ” 2768    πŸ’¬ 211    πŸ“Œ 332
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Student Airborne Research Program - NASA Science An eight-week immersive summer internship for undergraduates to gain hands-on research experience.

Students interested in #NASA and/or planet Earth 🌍 should really consider applying for SARP.

06.01.2025 20:30 β€” πŸ‘ 13    πŸ” 9    πŸ’¬ 0    πŸ“Œ 0

There are already some brilliant chemistry and #scicomm starter packs out there (which I’ll link below) but I haven’t seen one for chemistry content creators, authors and communicators yet, so I’ve made a start on one: go.bsky.app/4Fcuzus

Happy for suggestions of other accounts to add! #ChemSky

16.11.2024 07:45 β€” πŸ‘ 115    πŸ” 35    πŸ’¬ 18    πŸ“Œ 3

Has anyone on #chemsky written a successful NASA proposal and would be willing to share it for reference please? Thanks!

18.12.2024 21:38 β€” πŸ‘ 7    πŸ” 6    πŸ’¬ 2    πŸ“Œ 0

@pedroafs is following 20 prominent accounts