Environmental Science & Technology Letters,
Год журнала:
2023,
Номер
10(8), С. 675 - 679
Опубликована: Июль 24, 2023
Recent
interest
in
commercial
devices
containing
germicidal
ultraviolet
lamps
with
a
peak
emission
wavelength
at
222
nm
(GUV222)
has
focused
on
mitigating
virus
transmission
indoors
while
posing
minimum
risk
to
human
tissue.
However,
light
can
produce
ozone
(O3)
air.
O3
is
an
undesirable
component
of
indoor
air
because
health
impacts
from
acute
chronic
exposure
and
its
ability
degrade
quality
through
oxidation
chemistry.
In
seven
4
h
experiments,
we
measured
the
production
single
filtered
GUV222
lamp
31.5
m3
stainless
steel
chamber.
Using
model,
determined
generation
rate
19.4
ppbv
h–1
±
0.3
(equivalent
1.22
mg
0.02
h–1).
We
estimated
fluence
using
two
methods:
(1)
chemical
actinometry
tetrachloroethylene
(actinometry)
(2)
geometric
projection
irradiance
field
radial
angular
distribution
measurements
(irradiance).
rates
2.2
μW
cm–2
3.2
(irradiance),
predicted
our
chamber
within
20%
average
mixing
ratio.
Future
studies
should
evaluate
technologies.
ACS ES&T Air,
Год журнала:
2024,
Номер
1(7), С. 725 - 733
Опубликована: Май 4, 2024
Since
the
1930s,
germicidal
ultraviolet
(GUV)
irradiation
has
been
used
indoors
to
prevent
transmission
of
airborne
diseases,
such
as
tuberculosis
and
measles.
Recently,
it
received
renewed
attention
due
COVID-19
pandemic.
While
GUV
radiation
shown
be
effective
in
inactivating
bacteria
viruses,
few
studies
on
impact
indoor
air
quality
have
published.
In
this
work,
we
evaluate
effects
GUV222
(GUV
at
222
nm)
chemistry
a
common
volatile
organic
compound
(VOC),
limonene.
We
found
that
production
O3
by
lamps
caused
formation
particulate
matter
(PM)
oxygenated
compounds
(VOCs).
also
proceeds
through
ozonolysis
limonene
well
reaction
with
secondary
OH,
presence
light
led
observable
but
small
perturbations
chemistry.
Understanding
is
important
evaluating
safety
these
devices.
Environmental Health Perspectives,
Год журнала:
2024,
Номер
132(5)
Опубликована: Май 1, 2024
In
response
to
the
COVID-19
pandemic,
new
evidence-based
strategies
have
emerged
for
reducing
transmission
of
respiratory
infections
through
management
indoor
air.
Environmental Science Processes & Impacts,
Год журнала:
2024,
Номер
26(6), С. 1090 - 1106
Опубликована: Янв. 1, 2024
Devices
using
222
nm
germicidal
ultraviolet
light
(GUV222)
have
been
marketed
to
reduce
virus
transmission
indoors.
However,
GUV222
generates
ozone
which
can
react
with
gases
and
surfaces
create
undesirable
air
byproducts.
Health Security,
Год журнала:
2024,
Номер
22(2), С. 108 - 129
Опубликована: Апрель 1, 2024
In
2022,
the
Pentagon
Force
Protection
Agency
found
threat
agnostic
detection
of
novel
bioaerosol
threats
to
be
"not
feasible
for
daily
operations"
due
cost
reagents
used
metagenomics,
sequencing
instruments,
and
labor
subject
matter
experts
analyze
bioinformatics.
Similar
operational
difficulties
might
extend
many
280,000
buildings
(totaling
2.3
billion
square
feet)
at
5,000
secure
US
Department
Defense
military
sites,
250
Navy
ships,
as
well
civilian
buildings.
These
economic
barriers
can
still
addressed
in
a
manner
by
dynamically
pooling
samples
from
dry
filter
units,
called
spike-triggered
virtualization,
whereby
depth
are
automatically
modulated
based
on
biothreats
output.
By
running
high
average
factor,
annual
per
unit
reduced
10
100
times
depending
chosen
trigger
thresholds.
Artificial
intelligence
further
enhance
sensitivity
virtualization.
The
risk
infection
during
12-
24-hour
window
between
incident
its
remains,
but
some
cases
it
80%
or
more
with
high-speed
indoor
air
cleaning
exceeding
12
changes
hour,
which
is
similar
rate
passenger
airplanes
flight.
That
level
hour
higher
likely
cost-prohibitive
using
central
heating
ventilation
conditioning
systems,
achieved
economically
portable
filtration
rooms
typical
ceiling
heights
(less
than
approximately
$0.50
$1
foot
do-it-yourself
units
$2
$5
high-efficiency
particulate
filters.
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(18), С. 7916 - 7923
Опубликована: Апрель 29, 2024
In
response
to
the
COVID-19
pandemic,
air
cleaning
technologies
were
promoted
as
useful
tools
for
disinfecting
public
spaces
and
combating
airborne
pathogen
transmission.
However,
no
standard
method
exists
assess
potentially
harmful
byproduct
formation
from
cleaners.
Through
a
consensus
development
process,
draft
test
portable
cleaner
performance
was
developed,
suite
of
cleaners
employing
seven
different
tested.
The
quantifies
not
only
removal
efficiency
challenge
chemical
ultrafine
particulate
matter
but
also
formation.
Clean
delivery
rates
(CADRs)
are
used
quantify
particle
efficiencies,
an
emission
rate
framework
is
formaldehyde,
ozone,
other
volatile
organic
compounds.
We
find
that
tested
photocatalytic
oxidation
germicidal
ultraviolet
light
(GUV)
produced
highest
levels
aldehyde
byproducts
having
202
243
μg
h
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(27), С. 12051 - 12061
Опубликована: Июнь 26, 2024
Germicidal
ultraviolet
light
(GUV)
systems
are
designed
to
control
airborne
pathogen
transmission
in
buildings.
However,
it
is
important
acknowledge
that
certain
conditions
and
system
configurations
may
lead
GUV
produce
air
contaminants
including
oxidants
secondary
organic
aerosols
(SOA).
In
this
study,
we
modeled
the
formation
dispersion
of
generated
by
operation
employing
C
254
222
nm.
Using
a
three-dimensional
computational
fluid
dynamics
model,
examined
breathing
zone
concentrations
chemical
species
an
occupied
classroom.
Our
findings
indicate
operating
leads
approximate
increase
10
ppb
O3
concentration
5.2
μg·m–3
SOA
compared
condition
without
operation,
while
increases
about
1.2
μg·m–3,
with
minimal
impact
on
concentration.
Furthermore,
increasing
UV
fluence
rate
from
1
5
μW·cm–2
results
up
80%
concentrations.
For
254,
elevating
30
50
or
doubling
radiating
volume
50%
Note
indoor
airflow
patterns,
particularly
buoyancy-driven
(or
displacement
ventilation),
15–45%
lower
well-mixed
airflow.
The
also
reveal
when
ventilation
below
2
h–1,
has
smaller
human
exposure
than
222.
generate
more
at
high
levels
(>15
ppb).
These
suggest
design
should
consider
room
conditions.
Environmental Science & Technology,
Год журнала:
2024,
Номер
58(45), С. 20073 - 20080
Опубликована: Окт. 28, 2024
Germicidal
ultraviolet
lamps
with
a
peak
emission
at
222
nm
(GUV222)
are
gaining
prominence
as
safe
and
effective
solution
to
reduce
disease
transmission
in
occupied
indoor
environments.
While
previous
studies
have
reported
O