After
February
2020,
the
majority
of
world's
governments
decided
to
implement
a
lockdown
in
order
limit
spread
deadly
COVID-19
virus.This
restriction
improved
air
quality
by
reducing
emissions
particular
atmospheric
pollutants
from
industrial
and
vehicular
traffic.In
this
study,
we
look
at
how
shutdown
influenced
Lahore,
Pakistan.HAC
Agri
Limited,
Dawn
Food
Head
Office,
Phase
8-DHA,
Zeenat
Block
Lahore
were
chosen
give
historical
data
on
concentrations
many
pollutants,
including
PM2.5,
PM10
(particulate
matter),
NO2
(nitrogen
dioxide),
O3
(ozone)
(ozone).We
use
variety
models,
Decision
Tree,
SVR,
Random
Forest,
ARIMA,
CNN,
N-BEATS,
LSTM,
compare
forecast
quality.Using
machine
learning
methods,
looked
each
pollutant's
levels
changed
during
lockdown.It
has
been
shown
that
LSTM
estimates
amounts
pollutant
lockout
more
precisely
than
other
models.The
results
show
lockdown,
concentration
decreased,
index
around
20%.The
also
42%
drop
PM2.5
concentration,
72%
29%
an
increase
20%
concentration.The
models
are
assessed
using
RMSE,
MAE,
R-SQUARE
values.The
measures
4.35%,
8.2%,
4.46%,
8.58%
terms
MAE.It
is
observed
model
outperformed
with
fewest
errors
when
projected
values
compared
actual
values.
Journal of Geophysical Research Atmospheres,
Journal Year:
2025,
Volume and Issue:
130(2)
Published: Jan. 17, 2025
Abstract
Severe
haze
pollution
has
long
been
an
environmental
problem,
which
is
complicated
and
poorly
understood
in
the
Sichuan
Basin
(SCB).
In
this
study,
a
field
observation
was
carried
out
to
investigate
factors
driving
formation
urban
Chengdu,
typical
megacity
SCB.
It
found
that
accumulation
of
biomass
burning
organic
aerosol
(BBOA)
played
important
role
Chengdu.
The
average
mass
fraction
BBOA
PM
2.5
increased
from
∼1%
during
clear
days
∼10%
severe
episodes.
A
method
combining
backward
trajectory
analysis
with
fire
spot
distribution
used
evaluate
effects
regional
transport
(BB)
emissions.
results
showed
concentration
by
∼3
times
∼54%
when
BB
emissions
were
transported
adjacent
areas
Moreover,
parameter
f
60
(the
ratio
integrated
signal
at
m/z
total
component
spectrum),
indicated
impacts
emissions,
reassessed
be
0.54%
instead
widely
value
0.3%
previously.
Our
uncovered
importance
on
SCB
provided
new
insights
into
pollutant
mitigation
strategies
region.
PeerJ Computer Science,
Journal Year:
2023,
Volume and Issue:
9, P. e1270 - e1270
Published: March 31, 2023
After
February
2020,
the
majority
of
world's
governments
decided
to
implement
a
lockdown
in
order
limit
spread
deadly
COVID-19
virus.
This
restriction
improved
air
quality
by
reducing
emissions
particular
atmospheric
pollutants
from
industrial
and
vehicular
traffic.
In
this
study,
we
look
at
how
shutdown
influenced
Lahore,
Pakistan.
HAC
Agri
Limited,
Dawn
Food
Head
Office,
Phase
8-DHA,
Zeenat
Block
Lahore
were
chosen
give
historical
data
on
concentrations
many
pollutants,
including
PM2.5,
PM10
(particulate
matter),
NO2
(nitrogen
dioxide),
O3
(ozone).
We
use
variety
models,
decision
tree,
SVR,
random
forest,
ARIMA,
CNN,
N-BEATS,
LSTM,
compare
forecast
quality.
Using
machine
learning
methods,
looked
each
pollutant's
levels
changed
during
lockdown.
It
has
been
shown
that
LSTM
estimates
amounts
pollutant
lockout
more
precisely
than
other
models.
The
results
show
lockdown,
concentration
decreased,
index
around
20%.
also
42%
drop
PM2.5
concentration,
72%
29%
an
increase
20%
concentration.
models
are
assessed
using
RMSE,
MAE,
R-SQUARE
values.
measures
4.35%,
8.2%,
4.46%,
8.58%
terms
MAE.
is
observed
model
outperformed
with
fewest
errors
when
projected
values
compared
actual
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(17), P. 9733 - 9748
Published: Sept. 3, 2024
Abstract.
Black-carbon-containing
(BCc)
particles
are
ubiquitous
in
ambient
air,
significantly
contributing
to
particulate
matter
(PM)
pollution.
The
unexpected
outbreak
of
the
COVID-19
pandemic
summer
2021
prompted
a
localized
and
prolonged
lockdown
Yangzhou,
situated
Yangtze
River
Delta,
China.
This
led
significant
alteration
local
anthropogenic
emissions,
while
neighboring
cities
continued
regular
operations,
providing
unique
opportunity
for
investigation
BCc
particle
characteristics
influenced
by
varying
emission
conditions.
Single-particle
aerosol
mass
spectrometer
(SPA-MS)
analysis
revealed
notable
decrease
proportion
freshly
emitted
during
(LD)
period.
However,
PM2.5
concentrations
remained
relatively
unchanged,
with
an
observed
increase
aged
LD
compared
period
before
(BLD).
study
also
underscores
role
regional
transport
pollution
campaign.
Moreover,
reactive
trace
gases
(e.g.,
NOx,
SO2,
volatile
organic
compounds
–
VOCs)
could
form
thick
coatings
on
pre-existing
particles,
likely
via
enhanced
heterogeneous
hydrolysis
under
high
relative
humidity
(RH),
resulting
growth
(∼
600
nm),
as
well
concentration,
LD.
Our
highlights
that
short-term,
strict
controls
may
not
effectively
reduce
PM
due
complex
production
transmission
nonlinear
responses
its
precursors.
Achieving
further
effective
reduction
mandates
focus
nuanced
control
necessitates
comprehensive
extensive
approach
regionally
coordinated
balanced
strategy
through
joint
regulation.
Journal of the Air & Waste Management Association,
Journal Year:
2023,
Volume and Issue:
73(9), P. 649 - 678
Published: July 14, 2023
Clarifying
the
spatiotemporal
distribution
and
impact
mechanism
of
pollution
is
prerequisite
for
megacities
to
formulate
relevant
air
prevention
control
measures
achieve
carbon
neutrality
goals.
Chongqing
one
dual-core
key
in
Cheng-Yu
region
as
a
typical
mountain-city
China,
environmental
problems
are
complex
sensitive.
This
research
aims
investigate
exceeding
standard
levels
spatio-temporal
evolution
criteria
pollutants
between
2014
2020.
The
results
indicated
that
PM10,
PM2.5,
CO
SO2
were
decreased
significantly
by
45.91%,
52.86%,
38.89%
66.67%,
respectively.
Conversely,
concentration
pollutant
O3
present
fluctuating
growth
found
"seesaw"
phenomenon
it
PM.
Furthermore,
PM
highest
winter
summer,
SO2,
NO2,
CO,
showed
"U-shaped",
an
inverted
"U-shaped"
seasonal
variation.
concentrations
still
far
behind
WHO,
2021AQGs
standards.
Significant
spatial
heterogeneity
was
observed
distribution.
These
great
significance
"double
double
reduction"
PM2.5
pollution,
regional
peaking
roadmap
under
climate
coordination.
Besides,
can
provide
important
platform
exploring
terrain
around
world
references
related
epidemiological
research.Implication:
mountain
city,
Under
background
"14th
Five-Year
Plan",
construction
"Cheng-Yu
Dual-City
Economic
Circle"
"Dual-Carbon"
goal,
this
article
comprehensively
discussed
annual
excess
multiple
policy
newest
international
standards
(WHO,2021AQG)
backgrounds
from
2020
Chongqing.
suggestions
collaborative
management
discussed.
Finally,
limitations
recommendations
also
put
forward.Clarifying
cities
study
coordination
action
plan
sustained
improvement
quality.In
addition,
advanced
our
understanding
terrain.
promote
China
national
strategic
economic
circle
build
beautiful
west.
Moreover,
provides
scientific
insights
local
policymakers
guide
smart
urban
planning,
industrial
layout,
energy
structure,
transportation
planning
improve
quality
throughout
region.
conducive
future
other
regions
even
with
world.
Atmospheric chemistry and physics,
Journal Year:
2023,
Volume and Issue:
23(21), P. 13597 - 13611
Published: Nov. 1, 2023
Abstract.
Mixing
state
and
density
are
two
key
parameters
of
aerosol
particles
affecting
their
impacts
on
radiative
forcing
human
health.
Here
a
single-particle
mass
spectrometer
in
tandem
with
differential
mobility
analyzer
an
aerodynamic
classifier
was
deployed
during
the
Beijing
2022
Olympic
Winter
Games
(OWG)
to
investigate
emission
controls
particle
mixing
density.
Our
results
show
dominance
carbonaceous
comprising
mainly
total
elemental
carbon
(Total-EC,
13.4
%),
organic
(Total-OC,
10.5
%)
Total-ECOC
(47.1
%).
Particularly,
containing
sulfate
were
enhanced
significantly
OWG,
although
those
from
primary
emissions
decreased.
The
composition
also
changed
which
characterized
by
decreases
EC
mixed
nitrate
(EC-NS),
potassium
(KEC-N),
amine-containing
increase
ECOC
(ECOC-NS).
This
result
indicates
that
OWG
reduced
inorganic
species
amines
yet
increased
aerosol.
average
effective
(ρeff)
(150–300
nm)
1.15
g
cm−3
non-Olympic
(nOWG),
higher
values
(1.26
cm−3)
due
secondary
contribution.
In
addition,
ρeff
most
increases
pollution
levels
relative
humidity,
they
varied
differently
for
different
types
particles,
highlighting
aging
formation
processes
changes
state.
