Abstract.
To
reduce
the
uncertainties
in
identifying
key
volatile
organic
compounds
(VOCs)
species
influencing
ozone
(O3)
formation
based
on
observed
VOCs
concentrations,
this
study
proposed
identification
from
initial
concentrations.
The
concentrations
during
daytime
and
nighttime
were
calculated
using
reaction
rates
hourly
measured
99
at
Deyang,
Chengdu,
Meishan,
southwest
China
summer.
of
alkenes
aromatics
higher
than
ones.
largest
differences
between
1.04
ppbv
for
cis-2-butene
0.86
isoprene
1.98
respectively.
Due
to
secondary
production,
oxygenated
lower
-0.54
acetone
-0.58
acetaldehyde
-0.5
Based
top
three
contributing
O3
potential
cis-2-butene,
isoprene,
m,p-xylene
Deyang;
m,p-xylene,
Chengdu;
ethylene,
These
results
differed
those
Comprehensively
calculating
helps
accurately
identify
VOC
formation.
Atmosphere,
Год журнала:
2024,
Номер
15(4), С. 401 - 401
Опубликована: Март 25, 2024
Arizona,
a
rapidly
growing
state
in
the
southwestern
U.S.,
faces
ozone
pollution
challenges,
including
nonattainment
areas
Yuma
and
Maricopa
counties
influenced
by
neighboring
transport.
In
this
study,
we
use
five-year
(2017–2021)
hourly
back-trajectories
O3
concentration
data
for
concentration-weighted
trajectory
(CWT)
analysis
to
identify
transport
pathways
potential
source
regions
of
at
six
monitoring
sites
Arizona.
We
divide
into
five
seasons
(winter,
spring,
dry
summer,
monsoon
fall)
examine
variations
across
seasons.
The
highest
mean
concentrations
occur
during
spring
(37–49
ppb),
summer
(39–51
(34–49
while
winter
(19–41
ppb)
exhibits
lowest
seasonal
mean.
CWT
results
reveal
that
high
(≥40
with
exception
Phoenix
Tucson
sites,
are
significantly
regional
international
transport,
especially
(14.9–35.4%)
(12.7–26.9%).
major
(excluding
sites)
predominantly
located
outside
This
study
highlights
critical
role
influencing
variability
within
Arizona
will
be
valuable
shaping
control
strategies
future.
Atmospheric chemistry and physics,
Год журнала:
2025,
Номер
25(6), С. 3807 - 3820
Опубликована: Апрель 1, 2025
Abstract.
The
emissions
and
secondary
transformations
of
volatile
organic
compounds
(VOCs)
play
a
significant
role
in
ozone
(O3)
formation.
Previous
studies
have
often
relied
on
ambient
VOC
concentrations
to
identify
key
species.
However,
represent
the
residual
after
emitted
VOCs
been
consumed,
which
can
introduce
substantial
uncertainties.
To
address
this
issue,
study
proposes
novel
method
species
both
anthropogenic
biogenic
emissions.
are
calculated
during
nighttime
daytime
summer
using
nitrate
radical,
O3,
hydroxyl
radical
reaction
rates
99
measured
at
Deyang,
Chengdu,
Meishan,
China.
alkenes
aromatics
higher
than
concentrations.
largest
differences
between
1.04
ppbv
for
cis-2-butene
0.81
isoprene
1.79
Meishan.
In
contrast,
due
production,
oxygenated
lower
−0.54
acetone
−0.58
acetaldehyde
−0.5
Based
concentrations,
is
one
top
three
contributing
O3
formation
all
sites,
may
be
overlooked
observed
Comprehensive
calculation
enables
accurately
identified.
Journal of Geophysical Research Atmospheres,
Год журнала:
2025,
Номер
130(9)
Опубликована: Май 8, 2025
Abstract
The
proportion
of
more
active
volatile
organic
compounds
(VOCs)
species
decreases
with
altitude,
whereas
radiation
increases
vertically
due
to
aerosol
scattering
near
the
surface,
exerting
opposite
effects
on
vertical
O
3
generation.
Using
observation‐based
model
(OBM)
constrained
by
profiles,
we
identified
that
effect
(ARE)
has
a
stronger
impact
photochemical
characteristics
and
‐NOx‐VOC
sensitivity
than
VOCs
reactivity
(VRE).
ARE
is
dominant
factor,
promoting
formation
·OH
(increases
36.7%
106.3%),
enhancing
high‐altitude
oxidation,
shifting
parts
VOC‐limited
regimes
NOx‐limited
(VOCs/NOx
ratio
21.1%).
Additionally,
rapid
NOx
depletion
altitude
leads
limitation
aloft,
amplifying
ARE's
(ratio
28.1%).
These
findings
improve
understanding
ozone
generation
conditions
suggest
attention
should
be
paid
environments
in
surface
management.
Atmosphere,
Год журнала:
2024,
Номер
15(2), С. 232 - 232
Опубликована: Фев. 15, 2024
Simultaneous
measurements
of
atmospheric
volatile
organic
compounds
(VOCs),
conventional
gases
and
meteorological
parameters
were
performed
at
an
urban
site
in
Jinan,
East
China,
June
2021
to
explore
the
formation
evolution
mechanisms
summertime
ozone
(O3)
pollution
events.
O3
Episode
Ⅰ,
II,
non-O3
episodes
identified
based
on
China
Ambient
Air
Quality
Standards
differences
precursor
concentrations.
The
concentrations
I
II
145.4
μg/m3
166.4
μg/m3,
respectively,
which
significantly
higher
than
that
episode
(90
μg/m3).
For
precursors,
VOCs
NOx
increased
by
48%
34%
I,
decreased
21%
27%
compared
days.
analysis
m,p-xylene
ethylbenzene
ratio
(X/E)
OH
exposure
demonstrated
aging
air
masses
was
other
two
episodes,
could
not
be
explained
localized
photochemical
consumption.
Therefore,
we
speculate
high
driven
regional
transport
its
precursors.
Backward
trajectory
simulations
indicated
during
concentrated
from
south.
In
contrast,
combination
favorable
conditions
(high
temperatures
low
humidity)
led
excess
I.
Positive
matrix
factorization
(PMF)
model
results
emissions
combustion
gasoline
vehicle
exhausts
contributed
elevated
solvent
usage
may
important
contributor
formation.
this
study
emphasize
importance
strengthening
joint
control
precursors
with
neighboring
cities,
especially
south,
is
crucial
for
Jinan
mitigate
pollution.
Toxics,
Год журнала:
2024,
Номер
12(12), С. 868 - 868
Опубликована: Ноя. 29, 2024
This
study
investigates
the
chemical
complexity
and
toxicity
of
volatile
organic
compounds
(VOCs)
emitted
from
national
petrochemical
industrial
parks
their
effects
on
air
quality
in
an
area
Nanjing,
China.
Field
measurements
were
conducted
1
December
2022,
to
17
April
2023,
focusing
VOC
concentrations
speciations,
diurnal
variations,
ozone
formation
potential
(OFP),
source
identification,
associated
health
risks.
The
results
revealed
average
total
(TVOC)
concentration
15.9
±
12.9
ppb
OFP
90.1
109.5
μg
m−3.
Alkanes
constituted
largest
fraction
VOCs,
accounting
for
44.1%,
while
alkenes
emerged
as
primary
contributors
OFP,
comprising
52.8%.
TVOC
peaked
before
dawn,
a
pattern
attributed
early
morning
activities
nighttime
heavy
vehicle
operations.
During
periods
classified
clean,
when
levels
below
160
m−3,
both
(15.9
ppb)
(90.4
110.0
m−3)
higher
than
those
during
polluted
hours.
analysis
identified
key
sources
emissions,
including
automobile
exhaust,
oil
gas
evaporation,
discharges,
with
additional
pollution
adjacent
regions.
Health
risk
assessments
indicated
that
acrolein
exceeded
non-carcinogenic
threshold
at
specific
times.
Moreover,
trichloromethane,
1,3-butadiene,
1,2-dichloroethane,
benzene
found
surpass
acceptable
lifetime
carcinogenic
level
(1
×
10−6)
certain
periods.
These
findings
highlight
urgent
need
enhanced
monitoring
regulatory
measures
aimed
mitigating
emissions
protecting
public
areas.
In
context
complex
urban
areas,
policymakers
should
focus
controlling
which
can
not
only
reduce
secondary
pollution,
but
also
inhibit
harm
toxic
substances
human
health.
