Feed: Slashdot
Feed Link: https://slashdot.org/
---

Title: Most Air Cleaning Devices Have Not Been Tested On People

Link: https://science.slashdot.org/story/25/08/20/2...

A new review of nearly 700 studies on portable air cleaners found that over
90% of them were tested in empty spaces, not on people, leaving major gaps in
evidence about whether these devices actually prevent infections or if they
might even cause harm by releasing chemicals like ozone or formaldehyde. The
Conversation reports: Many respiratory viruses, such as COVID-19 and
influenza, can spread through indoor air. Technologies such as HEPA filters,
ultraviolet light and special ventilation designs -- collectively known as
engineering infection controls -- are intended to clean indoor air and
prevent viruses and other disease-causing pathogens from spreading. Along
with our colleagues across three academic institutions and two government
science agencies, we identified and analyzed every research study evaluating
the effectiveness of these technologies published from the 1920s through 2023
-- 672 of them in total. These studies assessed performance in three main
ways: Some measured whether the interventions reduced infections in people;
others used animals such as guinea pigs or mice; and the rest took air
samples to determine whether the devices reduced the number of small
particles or microbes in the air. Only about 8% of the studies tested
effectiveness on people, while over 90% tested the devices in unoccupied
spaces. We found substantial variation across different technologies. For
example, 44 studies examined an air cleaning process called photocatalytic
oxidation, which produces chemicals that kill microbes, but only one of those
tested whether the technology prevented infections in people. Another 35
studies evaluated plasma-based technologies for killing microbes, and none
involved human participants. We also found 43 studies on filters
incorporating nanomaterials designed to both capture and kill microbes --
again, none included human testing.

Read more of this story at Slashdot.

---
VRSS v2.1.180528