Face masks protect against aerosolized toxins from algal blooms, study
finds
Researchers found that low-cost face masks and AC filters are effective against toxic algae in air

Date:
August 6, 2021
Source:
University of Miami Rosenstiel School of Marine & Atmospheric
Science
Summary:
Intense blooms of toxic algae are becoming common occurrences
along the coast of Florida and elsewhere. Results from a new study
found that wearing the face mask everyone has become accustomed
to during the COVID- 19 pandemic may help protect against these
airborne toxins too.



FULL STORY ========================================================================== Intense blooms of toxic algae are becoming common occurrences along
the coast of Florida and elsewhere. Results from a new study led by
University of Miami (UM) scientists found that wearing the face mask
everyone has become accustomed to during the COVID-19 pandemic may help
protect against these airborne toxins too.


==========================================================================
The UM Rosenstiel School of Marine and Atmospheric Science researchers
designed an experiment to understand how effective commonly available
air conditioner filters and face masks are at filtrating out the toxins
emitted during harmful algal bloom events.

"We found that face masks and air conditioner filters with high filter performance ratings can reduce the risk of exposure by filtering
out small, toxin-containing particles," said the study's lead author
Cassandra Gaston, an assistant professor of atmospheric sciences at the
UM Rosenstiel School.

"These filter materials can also be effective at filtering out other
kinds of small particles as well," said Haley Royer, a co-first author
of the study and Ph.D. student at the UM Rosenstiel School's Department
of Atmospheric Sciences.

"As we all know by now, face masks are essential in preventing the
transmission of COVID-19 from person to person." Harmful algal blooms,
often referred to as red tides and blue-green algae, are exacerbated by nutrient-rich runoff from agriculture and industrial waste that end up in waterways. Noxious particles enter the air mostly from the breaking of
waves, resulting in airborne toxins that cause serious health problems
to humans and marine life. Airborne toxins can also affect indoor air
quality particularly for businesses and homes near contaminated waterways.

To conduct the experiment, the researchers created a bubbling device to
produce airborne toxin-containing particles in the lab by bubbling air
into the liquid containing cultures of a toxic-producing blue-green algae, Microcystis aeruginosa. Cutouts of three types of face masks and six
types of AC filters purchased from home improvement stores were placed
in-line with generated particles to determine how well the masks and
filters blocked particles of different sizes. The researchers used N95, disposable surgical mask and medical-grade, odor-filtering carbon fiber
masks. For AC filters, the researchers used filters for window units and central air conditioning units with different filter performance ratings.

They found that AC filters filtered out 20-90% of the airborne
particles with particle filtration increasing with increasing filter performance rating. Face masks filtered out over 90% of toxin-containing particles. The findings suggest that low-cost, commercially available
face masks and AC filters with high filtration efficiency ratings can
help avoid both indoor and outdoor exposure to harmful algal bloom toxins
in the air.

Harmful algal blooms are expected to become more prevalent worldwide
due to climate change and increased nutrient runoff from a growing
human population.

According to the researchers, the study also has relevance for the
transmission of SARS-CoV-2, the virus responsible for the current
COVID-19 pandemic. The virus has an average size of 60-140 nanometers,
which is within the size of particles investigated in this study.

The study, titled "Filtration Efficiency of Air Conditioner Filters and
Face Masks to Limit Exposure to Aerosolized Algal Toxins," was accepted
for publication on April 20, 2021 in the journal Aerosol and Air Quality Research.

The study's authors include: Cassandra Gaston, Haley Royer, Raymond Leibensperger III, Daniela Maizel, Kaycie Lanpher, Helena Solo-Gabriele,
Larry Brand, R. Grace Zhai, Alberto Caban-Martinez and Kimberly Popendorf
from the University of Miami.

Funding for the study was provided by the UM Laboratory of Integrated
Knowledge (U-LINK) and Florida Department of Health (DOH) project
"Diversity and Innovation in Screening and Prevention of Exposure over
the Long-term (DISPEL) to HABs." DOH funding supported preparation of
visual and video materials for communicating strategies to the public
for reducing HAB exposures.

========================================================================== Story Source: Materials provided by University_of_Miami_Rosenstiel_School_of_Marine_&
Atmospheric_Science. Original written by Diana Udel. Note: Content may
be edited for style and length.


========================================================================== Related Multimedia:
* YouTube_video:_Protecting_yourself_from_harmful_algal_blooms_(HABs) ========================================================================== Journal Reference:
1. Cassandra J. Gaston, Haley M. Royer, Raymond J. III Leibensperger,
Daniela Maizel, Kaycie B. Lanpher, Helena Solo-Gabriele, Larry
E. Brand, R. Grace Zhai, Alberto J. Caban-Martinez, Kimberly
J. Popendorf.

Filtration Efficiency of Air Conditioner Filters and Face Masks
to Limit Exposure to Aerosolized Algal Toxins. Aerosol and Air
Quality Research, 2021; 21 (8): 210016 DOI: 10.4209/aaqr.210016 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/08/210806171908.htm

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