Jeff Gilchrist Profile picture
PhD Biomedical researcher, data scientist, and finder of large prime numbers. Views are my own. @jeffgilchrist@mstdn.science @jeffgilchrist.bsky.social
86 subscribers
Nov 10 16 tweets 5 min read
COVID-19: Stats, Guides, Articles, Calculators

COVID-19 guides, useful info, stats, calculators & 600+ scientific articles: covid.gilchrist.ca

Ottawa, Canada weekly stats: covid.gilchrist.ca/Ottawa.html

Ontario, Canada weekly stats: covid.gilchrist.ca/Ontario.html

🧵1/ Graph of COVID-19 wastewater levels in Ottawa, Ontario, measured from Sept. 1, 2021. Weekly stats available at ( http://covid.gilchrist.ca/Ottawa.html )
Sankey graph (height of each bar is # of sequences for that variant) showing top variants and their lineages over the past 6 weeks from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D&pageName=ReportSection32240d6b62ba73667e98 )
A sample of some threads listed on the website ( covid.gilchrist.ca ):

How do variant designations work and relate to our immunity ( x.com/jeffgilchrist/… )? 2/
Nov 10 9 tweets 3 min read
#Variant update for #Ontario, #Canada (to Oct 29, 2024)

The KP.3.1.1 #DeFLuQE variant is having some competition from XEC and MC.1 now. Graph tools by @Mike_Honey_ 🧵1/ Graph of top 7 COVID variants from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D ) XEC is a combination of KP.3.3 and KS.1.1 that recombined together. MC.1 is a direct descendant of KP.3.1.1 with one spike mutation at T571I. To learn more about how variant naming works, you can read this article I wrote with @paulseaman31 ( ). 2/docs.google.com/document/d/1q0…
Sep 22 4 tweets 2 min read
Ceilings fans can reduce short-range viral concentrations close to the infected (54%-77%) while increasing long-range levels (5%-14%). Only recommended when # people in room is less than decision tool for various ventilation rates with not highly contagious pathogens (e.g. cold).

Decision tool for using or not using fans to mix the air in the room. Decision tool for using or not using fans under various ventilation rates (200, 400, and 800 m³/h) on reducing overall airborne transmission risk, considering occupants with and without the use of masks. The logarithmic scale on the left vertical axis shows the contagiousness of the pathogen, which indicates the quanta emission rate. The horizontal axis measures the number of people at long-range distances in relation to per person ventilation rates. The range of conditions that using fans is beneficial is filled in turqu...
The number concentration of lumped tracer particles between 0.3 and 5.0 μm for both short-range and long-range routes, respectively.
Link to full study here ( ).sciencedirect.com/science/articl…
Sep 19 89 tweets 20 min read
Variants: JN.1 vs KP.2 vs KP.3.1.1

What do the variant designations like KP.3.1.1 mean and how does it compare to JN.1? How important is just 1 mutation? Can 1 mutation potentially affect our immunity and how vaccines are designed? Read on to find out more. @paulseaman31 🧵1/ Structural alignment of the AF2-predicted RBD conformational ensembles in the complexes with ACE2 for JN.1 (A), KP.2 (B) and KP.3 variants (C). Structural alignment of the AF2-predicted conformations with high pLDDT values > 80.0 and the cryo-EM structure of the BA.2.86 RBD-ACE2 complex (pdb id 8QSQ). The RBD conformations are shown in ribbons. The sites of unique BA.2.86 mutations D339H, K356T, R403K, V445H, G446S, N450D, L452W, N460K, N481K, A484K, F486P, R493Q are shown in blue spheres on panels (A-C). Mutation L455S in JN.1 is shown in red spheres on panel A. The positions of KP.2 mutat... The web version of this article with nice table of contents and is easy to share with others can be found here ( ) or ( ). 2/ tinyurl.com/VariantsSummer…
docs.google.com/document/d/1q0…
Table of Contents Variant Designations (e.g. KP.3.1.1) - Parent & Child Lineages - KP.3 vs KP.3.1 vs KP.3.1.1 - Variants that Start with X How does this relate to our immunity? How important is 1 mutation? What variants are circulating now? - Canada - USA - United Kingdom - Europe - Asia - South America -Oceania
Aug 28 4 tweets 2 min read
Virus update for Ottawa, Canada (Aug 28, 2024)

COVID-19 #Wastewater levels in #Ottawa are up again with the circulation of a new KP.3.1.1 DeFLuQE variant ( ). Wastewater is still being updated but on a weekly basis now. 🧵1/3 covid.gilchrist.ca/Ottawa.html
Image New hospitalizations in Ottawa *due* to COVID-19, Flu or RSV are unfortunately increasing again. There were two big spikes over the past month ( ). 2/3 ottawapublichealth.ca/en/reports-res…
Graph of New Hospitalizations in Ottawa *due to* COVID-19, Influenza or RSV. Weekly stats available at ( http://covid.gilchrist.ca/Ottawa.html )
Aug 23 14 tweets 4 min read
#Variant update for #Ontario, #Canada (to Aug 13, 2024)

Today's variant show is brought to you by the letters KP... Looks like KP.3.1.1 has really taken off and separated from the pack at 40% prevalence in Ontario. Graph tools by @Mike_Honey_ 🧵1/ Graph of top 7 COVID variants from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D ) KP.3.1.1 has the #FLuQE mutations and also a key point in the spike protein deleted which gives it much more immune evasion than other variants. 2/
Jul 25 10 tweets 3 min read
No Novavax JN.1 vaccine for Canada?

It seems Canada has not ordered any Novavax JN.1 vaccine doses for the fall which means this protein based vaccine option may not be available to anyone who wants or needs it. We are hoping you can help us change that. 🧵1/ English executive summary: A group of concerned stakeholders advocating for broader access to diverse COVID-19 vaccine options for Canadians, particularly those beyond the mRNA vaccines currently dominating the public offering wrote a letter to the Public Health Agency of Canada (PHAC), all the provinces/territories and immunization providers to address the pressing need for enhanced COVID-19 awareness and education, increased availability and access to protein-based vaccines, such as Novavax, which are currently limited in distribution. A group of concerned stakeholders advocating for broader access to diverse COVID-19 vaccine options for Canadians, particularly those beyond the mRNA vaccines currently dominating the public offering wrote a letter to the Public Health Agency of Canada (PHAC)... 2/ Resume francais: Nous vous écrivons en tant que parties prenantes revendiquant un accès plus large aux différentes options de vaccins contre la COVID-19 pour les Canadiens, particulièrement au-delà des vaccins à ARNm qui dominent présentement l’offre publique. Nous exhortons l’Agence de la santé publique du Canada (ASPC), toutes les provinces et tous les territoires ainsi que tous ceux qui fournissent des vaccins à s’attaquer au besoin pressant d’une meilleure sensibilisation et éducation sur la COVID-19, ce qui inclut une plus grande disponibilité et un meilleur accès aux vaccins à base de...
May 22 34 tweets 8 min read
Novavax JN.1 Vaccine Neutralization

Novavax revealed they had selected the original JN.1 variant as their fall booster and recently released neutralization results on non-human primates (Macaques) including a more recent KP.2 FLiRT variant. 🧵1/
Graph of JN.1 vaccine neutralizing response against JN.1 and JN.1 subvariants in non-human primates (macaques)
Graph of Novavax JN.1 Vaccine Neutralization Dose Schedule
Recall that the JN.1 variant became dominant in many parts of the world in December 2023 so by the time the fall 2024 vaccine program rolls out it will be almost a year old. 2/
May 20 84 tweets 21 min read
Indoor Air Quality: Wildfire Smoke & Cooking

With wildfire smoke season here, we all need to think about air quality inside where we spend most of our time. This thread provides multiple examples measuring the air quality inside my home from wildfire smoke and cooking. 🧵1/

Wildfire smoke making it difficult to see buildings in New York City from ( https://www.theguardian.com/environment/2023/jun/08/air-quality-record-smoke-hazard-wildfire-worst-day-ever-canada-new-york ).
Graph of PM 2.5 Wildfire Smoke Pollution Levels Inside & Outside House with significantly higher levels of PM outside and in garage, and higher levels of PM in unfinished sections of basement with very little PM in finished rooms and those with HEPA filters.
Graph from co2.click portal showing a massive spike in particulate matter (PM) levels past 50 ug/m3 on Christmas Eve. More info at: https://co2.click/
The web version of this article with nice table of contents and easy to share with others can be found here ( ) or ( ). 2/ tinyurl.com/AirQualityPoll…
docs.google.com/document/d/1x0…
Image
May 13 15 tweets 5 min read
#Variant update for #Ontario, #Canada (to May 12 2024)

The JN.1.* +FLiRT variants now make up 27% of sequences and XDK.* which is recombinant of JN.1.1.1 and XBB.1.16.11 is remaining at 5% for now. Graph tools by @Mike_Honey_ 🧵1/
Sankey graph (height of each bar is # of sequences for that variant) showing top variants and their lineages over the past couple of months from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D&pageName=ReportSection32240d6b62ba73667e98 )
Graph of top 7 COVID variant clans from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D
JN.1 #Pirola has dropped to 7% frequency and JN.1.4 down to 9% while KP.3 FLuQE is now most prevalent at 26% while the FLiRT variants are much lower at KP.2 (6%) and KS.1 (5%). 2/ Graph of top 8 COVID variants (JN.1, JN.1.4, JN.1.7, JN.1.8.1, KP.2, KP.3, KS.1) from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D )
Apr 29 12 tweets 3 min read
People are rightfully concerned about the high case fatality rate (CFR) of the H5N1 influenza virus but did you know fatalities from COVID infection (which already spreads easily between humans) with the elderly are as high as 40% ( )? 🧵1/ Virus infection can damage the body, we have seen this with Long COVID and this can happen with other viruses as well such as Influenza causing increased risk of cardiovascular events among other things. 2/
Apr 28 17 tweets 5 min read
#Variant update for #Ontario, #Canada (to Apr. 17, 2024)

The JN.1.* +FLiRT variants now make up 20% of sequences and XDK.* which is recombinant of JN.1.1.1 and XBB.1.16.11 has made an appearance at 5%. Graph tools by @Mike_Honey_ 🧵1/
Sankey graph (height of each bar is # of sequences for that variant) showing top variants and their lineages over the past couple of months from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D&pageName=ReportSection32240d6b62ba73667e98 )
Graph of top 7 COVID variant clans from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D
FLiRT is a nickname for variants with F456L & R356T mutations which seem to provide an advantage over the JN.1 Pirola variants without them. You can see the current FLiRT variants here from @dfocosi. 2/ Chart of BA.2.86* variant convergence and latest FLiRT mutations. Chat by @dfocosi ( https://twitter.com/dfocosi/status/1780183036853690596 )
Apr 20 13 tweets 4 min read
#Variant update for #Ontario, #Canada (to Apr. 9, 2024)

The regular BA.2.86.*/JN.1.* #Pirola clan of variants as you know them are starting to go down in Ontario. This is because descendants are picking up two very useful FLiRT mutations. Graph tools by @Mike_Honey_ 🧵1/
Sankey graph (height of each bar is # of sequences for that variant) showing top variants and their lineages over the past couple of months from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D&pageName=ReportSection32240d6b62ba73667e98 )
Graph of top 7 COVID variant clans from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D
FLiRT is a nickname for variants with F456L & R356T mutations which seem to provide an advantage over the JN.1 Pirola variants without them. You can see the current FLiRT variants here from @dfocosi. 2/ Chart of BA.2.86* variant convergence and latest FLiRT mutations. Chat by @dfocosi ( https://twitter.com/dfocosi/status/1780183036853690596 )
Mar 25 7 tweets 2 min read
PHO is reminding HCWs, even those who have been vaccinated, to wear an N95 while providing care to people with confirmed or suspected cases because they know N95s can prevent infection from infectious aerosols. Works for other airborne viruses as well and non-HCW too. Respirators protect individuals who are healthy and help reduce the chance of individuals who are sick from infecting others even in well ventilated places where short-range transmission is a concern. 2/
Mar 25 12 tweets 4 min read
Virus update for Ottawa, Canada (Mar 25, 2024)

COVID-19 #Wastewater levels in #Ottawa have finally declined significantly but lower does not mean gone as PCR test positivity rates are still at 7.6% ( ). 🧵1/ covid.gilchrist.ca/Ottawa.html
Graph of COVID-19 wastewater levels in Ottawa, Ontario. Weekly stats available at ( http://covid.gilchrist.ca/Ottawa.html ) RSV WW levels are 7.7x lower than the peak which was much lower than last year. Influenza had much higher peaks this year than last year and while Flu A levels are low, Flu B hit its peak at the beginning of March and is now declining but still above the peak from last year. 2/ Graph of RSV, Influenza A & B wastewater levels in Ottawa, Ontario. Weekly stats available at ( http://covid.gilchrist.ca/Ottawa.html )
Mar 24 8 tweets 3 min read
#Variant update for #Ontario, #Canada (to Mar. 14, 2024)

The BA.2.86.* #Pirola clan of variants has made most other lineages extinct in Ontario. The SanKey shows the situation is now much simpler and almost exclusively JN.1 and descendants. Graph tools by @Mike_Honey_ 🧵1/
Sankey graph (height of each bar is # of sequences for that variant) showing top variants and their lineages over the past couple of months from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D&pageName=ReportSection32240d6b62ba73667e98 )
Graph of top 7 COVID variant clans from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D
Right now the JN.1 and JN.1.4 Pirola variant are still the most prevalent. The JN.1.11.1 variant, its descendants (KP.*) and other FLiRT variants will be the ones to watch as they start growing in Ontario and may be able to escape immunity from JN.1 infections. 2/ Graph of top 8 COVID variants (JN.1, JN.1.1, JN.1.11.1, JN.1.2, JN.1.22,, JN.1.4, JN.1.7, JN.1.8.1) from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D )
Mar 23 7 tweets 3 min read
Public Health Ontario (PHO) using different age categories for updated RV tool data

PHO now combines children <1 into a 0-4 age group while before they had separate <1 and 1-4 age categories which makes a big difference in how the impact of children is perceived. 🧵1/
Graph of Ontario hospitalization rate by age group for the 2023-24 surveillance period. Image from:  http://covid.gilchrist.ca/Ontario.html
Graph of COVID-19 average bed occupancy per 100k population by age group in Ontario for the 2023-24 surveillance period. Image from:  http://covid.gilchrist.ca/Ontario.html
PHO stopped updating COVID-19 hospital admissions and now provide bed occupancy in their recent Respiratory Virus Tool update which uses different age categories ( ). 2/publichealthontario.ca/en/Data-and-An…
Mar 20 8 tweets 2 min read
A nine year old boy named Matt in Singapore was infected with COVID in January 2024. Unfortunately he developed myocarditis (inflammation of the heart muscle) from the COVID infection and then had a stroke which weakened his left side ( ). 🧵1/ straitstimes.com/life/triple-wh…
From Jan 5 to 16, Matt Aeron Semodio was on ECMO, a life support system that temporarily does the job of the heart and lungs. PHOTO: COURTESY OF MATT AERON SEMODIO’S FAMILY. Image from: https://www.straitstimes.com/life/triple-whammy-nine-year-old-boy-in-singapore-suffers-covid-19-myocarditis-and-stroke After being admitted to hospital, his heart failed and he was required to be put on the most invasive form of life support extracorporeal membrane oxygenation (ECMO), which temporarily does the job of the heart and lungs. H/T: @MeetJess 2/
Mar 3 61 tweets 14 min read
Increased Measles in Canada - Are you protected?

As Public Health crumbles and too few people are getting vaccinated for measles our herd immunity levels have dropped too much and now many people are at risk for a disease we almost eradicated in Canada. 🧵1/ Various symptoms of measles. Fever, Cough, Blocked or running nose, red, sore and watery eyes, spots in mouth, measles rash. Image from: https://www.dailymail.co.uk/health/article-12991379/Symptoms-measles-runny-nose-rash-tell-apart.html Contents of Post:
* Worldwide Outbreaks
* Symptoms
* How is it Transmitted
* How to prevent Infection
* Damage from Measles
* Measles Depletes Immune Memory
* How long does Vaccine Last
* Breakthrough Infections
* Cleaning the Air

2/
Feb 28 6 tweets 3 min read
#Variant update for #Ontario, #Canada (to Feb. 21, 2024)

You can see how much the BA.2.86.* #Pirola clan of variants has made a clean sweep since January. The left SanKey shows the variant soup from December while the right is now much simpler. Graph tools by @Mike_Honey_ 🧵1/
Sankey graph (height of each bar is # of sequences for that variant) showing top variants and their lineages over the past couple of months from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D&pageName=ReportSection32240d6b62ba73667e98 )
Sankey graph (height of each bar is # of sequences for that variant) showing top variants and their lineages over the past couple of months from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D&pageName=ReportSection32240d6b62ba73667e98 )
The Pirola clan still makes up more than 90% of sequences in Ontario but may have reached its peak for now. The JN.1 variant dropped from 50% down to 38% while its child JN.1.4 is gaining ground above 25%. 2/
Graph of top 7 COVID variant clans from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D
Graph of top 7 COVID variants (HV.1, JG.3.2, JN.1, JN.1.1, JN.1.2, JN.1.22,, JN.1.4) from PCR test genomic sequencing in Ontario, Canada. Visualization tool was created by @Mike_Honey_ ( https://app.powerbi.com/view?r=eyJrIjoiNzE5YzczODItMDQzMS00M2EzLWFjNWYtMjg3OTY3NTNhZDM3IiwidCI6ImRjMWYwNGY1LWMxZTUtNDQyOS1hODEyLTU3OTNiZTQ1YmY5ZCIsImMiOjEwfQ%3D%3D )
Feb 17 25 tweets 7 min read
Particulate Matter (PM) from Showers

After I wrote about PM from ultrasonic humidifiers, people asked how much PM does a hot shower produce? TLDR: Much less for a quick shower, around 12 ug/m^3 compared to 800 ug/m^3 for the ultrasonic. 🧵1/ Graph of particulate matter (PM) levels from a 13 minute hot shower with bathroom exhaust fan running, increasing slightly to 4 ug/m^3 of PM2.5 at end of shower but then jumps to 12 ug/m^3 of PM2.5 after the shower door is opened and PM is released into the room. PM levels back to normal after about 20 minutes of the bathroom door being opened. PM monitor used was Model G from https://co2.click/ But not all PM is equal so look later in the thread for different types of PM that are more dangerous. 2/