American Journal of Applied Chemistry,
Год журнала:
2024,
Номер
12(6), С. 173 - 183
Опубликована: Дек. 30, 2024
Indoor
air
quality
(IAQ)
is
crucial
for
human
health,
especially
in
urban
areas
where
people
spend
most
of
their
time
indoors.
In
cities
like
Antananarivo
and
Mahajanga,
Madagascar,
various
factors
contribute
to
poor
IAQ,
posing
significant
health
risks.
A
total
26
samples
were
collected,
comprising
16
from
10
Mahajanga.
The
concentrations
PM<sub>2.5</sub>
metallic
trace
elements
(Aluminum
(Al),
Titanium
(Ti),
Chromium
(Cr),
Manganese
(Mn),
Iron
(Fe),
Nickel
(Ni),
Copper
(Cu),
Zinc
(Zn),
Lead
(Pb))
analyzed
using
descriptive
statistics.
Statistical
methods,
including
the
Shapiro-Wilk
test
normality,
independent
t-tests
comparing
means
between
cities,
one-way
ANOVA
analyzing
site-to-site
variation
within
applied
assess
data.
analysis
revealed
a
PM<sub>2.5
</sub>concentration
ranging
4.80
µg/m³
58.45
µg/m³,
with
mean
24.39
across
all
sampling
sites,
68.75%
50.00%
Mahajanga
exceeding
World
Health
Organization
(WHO)
guideline
15
µg/m³.
average
aluminium,
titanium,
chromium,
manganese,
iron,
nickel,
copper,
zinc
lead
0.6797
0.0382
0.0015
0.0176
0.4045
0.0001
0.0021
0.0076
0.0023
respectively.
showed
no
statistically
difference
</sub>concentrations
two
cities.
However,
indicated
variability
</sub>levels
among
different
sites
each
city,
highlighting
spatial
heterogeneity
indoor
pollutant
concentrations.
This
study
emphasizes
need
targeted,
localized
interventions
address
disparities
mitigate
risks
associated
elevated
environment.
findings
suggest
that
further
research
policy
efforts
should
focus
on
developing
strategies
improve
IAQ
Madagascar's
safeguard
public
health.
Nanomaterials,
Год журнала:
2024,
Номер
14(15), С. 1258 - 1258
Опубликована: Июль 27, 2024
The
upcoming
Euro
7
vehicle
exhaust
emissions
regulation
includes
particle
number
(PN)
limits
for
all
vehicles,
not
only
those
with
direct
fuel
injection.
It
also
sets
the
lower
detection
size
of
PN
methodology
to
10
nm
from
23
nm.
Recently,
a
commercial
diffusion
charger-based
PEMS
added
possibility
switching
between
and
In
this
study,
we
assessed
dual
in
calibration
laboratory
using
flame
soot
or
spark
discharge
graphite
particles
following
regulated
procedures.
Furthermore,
compared
grade
system
(LABS)
soot,
graphite,
particles.
To
put
results
into
perspective,
comparisons
(validations)
two
additional
PEMSs
LABSs
over
three-year
period.
showed
that
differences
remained
same
(around
35%
underestimation)
years
were
similar
PEMS.
This
difference
is
still
well
within
permissible
tolerance
(50%).
We
argued
reason
material
used
by
manufacturer
(spark
graphite).
demonstrated
calibrating
combustion
could
reduce
differences.
gave
but
much
smaller
differences,
indicating
less
importance
step.
measurement
uncertainty
has
increased
rather
decreased
specific
Processes,
Год журнала:
2025,
Номер
13(4), С. 1075 - 1075
Опубликована: Апрель 3, 2025
Ultra-high-efficiency
filter
media
ensure
high
air
cleanliness
but
need
periodic
replacement
due
to
pressure
drop
increase.
Adding
a
pre-filter
can
extend
the
filtration
system’s
service
lifetime,
yet
and
main-filter
matching
lacks
systematic
study.
This
research
explored
how
different
combinations
affected
two-stage
ultra-high-efficiency
performance.
study
focused
on
five
grades
(F7–F9,
H10,
H11)
two
types
of
media,
fiberglass
composite.
It
was
found
that
F8
had
best
effect
extending
lifetime
BX
+
PTFE.
The
lifetimes
were
extended
from
44
min
70
231
326
min,
respectively,
reaching
5.25
times
4.65
original
lifetime.
Moreover,
optimal
grade
less
by
initial
resistance
main
filter.
Meanwhile,
PTFE
system
always
showed
longer
dust
holding
capacity
compared
system.
provides
guidance
for
design
combination
filters
in
context
high-cleanliness
applications
as
well
improvement
multi-stage
performance
building
ventilation.
IntechOpen eBooks,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 22, 2025
Aerosols
significantly
influence
climate
and
public
health.
They
exhibit
diverse
physical
chemical
properties
originate
from
various
sources,
including
natural
anthropogenic
activities.
interact
with
solar
radiation
clouds,
affecting
Earth’s
energy
balance.
However,
their
complex
behavior
interactions
pose
challenges
for
accurate
quantification
prediction.
Health
risks
associated
aerosols,
particularly
PM2.5,
include
respiratory
cardiovascular
diseases.
Addressing
these
impacts
requires
a
multifaceted
approach,
combining
technological
innovation,
robust
air
quality
regulations,
international
collaboration.
Electrical
engineers
play
crucial
role
in
developing
advanced
sensors
monitoring
systems.
Future
research
priorities
refining
aerosol
characterization,
understanding
interactions,
assessing
long-term
health
impacts.
Socio-economic
considerations
are
effective
mitigation
strategies,
especially
resource-limited
settings.
Advancing
interdisciplinary
integrating
policies
essential
managing
creating
sustainable
future.
PLoS ONE,
Год журнала:
2025,
Номер
20(4), С. e0320405 - e0320405
Опубликована: Апрель 24, 2025
This
study
examines
the
distribution,
origins,
and
health
hazards
of
polycyclic
aromatic
hydrocarbons
(PAHs)
across
six
particle
size
fractions
obtained
from
an
urban
rooftop
location
in
Bangkok,
Thailand.
We
collected
PM
samples
using
a
six-stage
cascade
impactor
at
canal
boat
port,
trapping
PAHs
sizes
ranging
ultrafine
(PM
0.65–1.1
)
to
coarse
7.0
beyond
over
11-week
period.
utilized
gas
chromatography-mass
spectrometry
quantify
twelve
PAH
congeners.
Results
indicated
that
primarily
concentrate
fine
particles
2.1–3.3
),
with
traffic
emissions
gasoline
cars
being
principal
sources,
augmented
by
diesel
boats
industrial
activities.
The
risk
assessment
showed
lifetime
lung
cancer
(LLCR)
values
for
all
were
less
than
1×10
−6
.
means
exposure
this
area
has
very
low
risk.
Principal
Component
Analysis
(PCA)
Positive
Matrix
Factorization
(PMF)
found
as
primary
sources
PAHs,
accounting
5%
total.
These
findings
highlight
necessity
specific
emission
control
regulations
advocate
implementation
cleaner
fuel
alternatives
electric
propulsion
transit
enhance
air
quality
Bangkok.
Sensors,
Год журнала:
2024,
Номер
24(20), С. 6509 - 6509
Опубликована: Окт. 10, 2024
Thousands
of
particle
number
(PN)
counters
have
been
introduced
to
the
European
market,
following
implementation
PN
tests
during
periodic
technical
inspection
(PTI)
diesel
vehicles
equipped
with
particulate
filters.
Expanding
PN-PTI
test
gasoline
may
face
several
challenges
due
different
exhaust
aerosol
characteristics.
In
this
study,
two
instruments,
type-examined
for
vehicles,
measured
fifteen
petrol
passenger
cars
protocols:
low
and
high
idling,
or
without
additional
load,
sharp
accelerations.
The
one
based
on
diffusion
charging
other
condensation
counting,
demonstrated
good
linearity
compared
reference
instrumentation
R-squared
values
0.93
0.92,
respectively.
However,
in
a
considerable
tests,
they
registered
higher
concentrations
presence
below
their
theoretical
23
nm
cut-off
size.
evaluation
protocols
showed
that
direct
injection
engine
filters
(GPFs)
generally
emitted
an
order
magnitude
those
GPFs.
variations
concentration
levels
were
observed
each
vehicle.
Port-fuel
GPFs
mostly
near
lower
detection
limit
instruments.
