FINALLY, California public health🥑 got it right ✅. Now they show N95 as clearly superior b/c it has head-straps versus KN95/KF94, "They provide less protection than N95s because they have ear loops."
www.cdph.ca.gov/Programs/CID...

FULL DETAILS come to our presentation at #AAAR2025 in Buffalo, NY at 2:30pm on Wednesday, October 15, 2025

aaarabstracts.com/2025/view_ab...

TEST #1: Each filter was tested in a SAFE DIY air cleaner, a 20” box fan paired with a fan shroud and safety screen. The clean air delivery rate (CADR) for particles between 0.3–2.685 µm was evaluated using aerosolized sodium chloride (NaCl) particles operating on low fan speed.

HOW LONG DO MERV 16 FILTERS LAST 🏃🏃‍♀️🏃‍♂️?

CDC researcher Christopher Barnes and I decided to find out:

2 DIY SAFE boxes in elementary school 🏫 (16 months)

vs

3 DIY SAFE boxes (4 months) in middle school 🏫

All used daily (per teacher reports).

TEST PROCEDURE (6/5/2025):
1. Open windows to equalize aerosol concentration with outside
2. Close windows
3. Turn on air purifiers under test
4. Track aerosol concentration at 0.3 um every minute

(3/4)

DETAILS:
Classroom on 2nd floor of SF middle school
6600 cubic feet
Height 11' x Length 24' x Width 25'
No HVAC/ventilation system but it has 4 windows

(2/4)

2 YEARS UPDATE on DIY: This week I tested 10 DIY purifiers in 4 classrooms (160 in use). Still working great!! ✅

CDC & CDPH say we need 5+ air changes per hour (ACH). 🌪️

When I tested $1000+ district-supplied HEPA only 2.5 ACH (sp 2) vs 6.3 ACH for $400 DIY (sp 1) 👀

(1/4)

The CDC target could be reached in a typical classroom for US$250. www.patientknowhow.com/safe.html

Not too surprising that pollution 🔥 💨🚬 🚘 (PM 2.5) is linked to lung 🫁 cancer, but why would it increase risk of ANY CANCER?

“for every 10 microgram per cubic meter (µg/m3) of increased exposure to PM2.5, risk of dying from any cancer rose by 22 percent.”