Water,
Journal Year:
2024,
Volume and Issue:
16(2), P. 348 - 348
Published: Jan. 20, 2024
Plastic
debris
is
a
growing
threat
in
freshwater
ecosystems
and
transport
models
predict
that
many
plastics
will
sink
to
the
benthos.
Among
most
common
found
Laurentian
Great
Lakes
sediments
are
polyethylene
terephthalate
(especially
fibers;
PET),
polyvinylchloride
(particles;
PVC),
styrene-butadiene
rubber
resulting
from
tire
wear
(“crumb
rubber”;
SBR).
These
materials
vary
substantially
physical
chemical
properties,
their
impacts
on
benthic
biogeochemistry
microbial
community
structure
function
largely
unknown.
We
used
microcosm
approach
evaluate
impact
of
these
three
benthic-pelagic
coupling,
sediment
using
Irondequoit
Bay,
major
embayment
Lake
Ontario
Rochester,
New
York,
USA.
Benthic
metabolism
nitrogen
phosphorous
cycling
were
all
uniquely
impacted
by
different
polymers.
PET
fibers
PVC
particles
demonstrated
unique
effects,
with
decreased
ecosystem
containing
greater
nutrient
uptake
PVC.
Microbial
diversity
was
reduced
treatments
plastic,
but
SBR
had
substantial
function,
increasing
relative
importance
metabolic
pathways
such
as
hydrocarbon
degradation
sulfur
metabolism.
Our
results
suggest
individual
polymers
have
benthos,
divergent
implications
for
function.
This
provides
deeper
insight
into
myriad
ways
plastic
pollution
may
aquatic
help
inform
risk
assessment
policy
interventions
highlighting
which
pose
greatest
risk.
Environmental Science & Technology,
Journal Year:
2023,
Volume and Issue:
57(14), P. 5621 - 5632
Published: March 30, 2023
6PPD,
a
tire
rubber
antioxidant,
poses
substantial
ecological
risks
because
it
can
form
highly
toxic
quinone
transformation
product
(TP),
6PPD-quinone
(6PPDQ),
during
exposure
to
gas-phase
ozone.
Important
data
gaps
exist
regarding
the
structures,
reaction
mechanisms,
and
environmental
occurrence
of
TPs
from
6PPD
ozonation.
To
address
these
gaps,
ozonation
was
conducted
over
24–168
h
were
characterized
using
high-resolution
mass
spectrometry.
The
probable
structures
proposed
for
23
with
5
subsequently
standard-verified.
Consistent
prior
findings,
6PPDQ
(C18H22N2O2)
one
major
in
(∼1
19%
yield).
Notably,
not
observed
6QDI
(N-(1,3-dimethylbutyl)-N′-phenyl-p-quinonediimine),
indicating
that
formation
does
proceed
through
or
associated
TPs.
Other
included
multiple
C18H22N2O
C18H22N2O2
isomers,
presumptive
N-oxide,
N,N′-dioxide,
orthoquinone
structures.
Standard-verified
quantified
roadway-impacted
samples,
total
concentrations
130
±
3.2
μg/g
methanol
extracts
tread
wear
particles
(TWPs),
34
4
μg/g-TWP
aqueous
TWP
leachates,
2700
1500
ng/L
roadway
runoff,
1900
1200
creeks.
These
demonstrate
are
likely
an
important
ubiquitous
class
contaminants
environments.
Environmental Chemistry Letters,
Journal Year:
2023,
Volume and Issue:
21(6), P. 3055 - 3062
Published: Aug. 14, 2023
Abstract
Microplastic
pollution
is
occurring
in
most
ecosystem,
yet
their
presence
high
altitude
clouds
and
influence
on
cloud
formation
climate
change
are
poorly
known.
Here
we
analyzed
microplastics
water
sampled
at
the
summits
of
Japan
mountains
1300–3776
m
by
attenuated
total
reflection
imaging
micro-Fourier
transform
infrared
spectroscopy.
We
observed
nine
including
polyethylene,
polypropylene,
polyethylene
terephthalate,
polymethyl
methacrylate,
polyamide
6,
polycarbonate,
ethylene–propylene
copolymer
or
polyethylene–polypropylene
alloy,
polyurethane,
epoxy
resin.
were
fragmented,
with
mean
concentrations
ranging
from
6.7
to
13.9
pieces
per
liter,
Feret
diameters
7.1
94.6
μm.
Microplastics
bearing
hydrophilic
groups
such
as
carbonyl
and/or
hydroxyl
abundant,
suggesting
that
they
might
have
acted
condensation
nuclei
ice
water.
Overall,
our
finding
suggest
high-altitude
and,
turn,
modify
climate.
Environmental Science & Technology,
Journal Year:
2023,
Volume and Issue:
57(36), P. 13429 - 13438
Published: Aug. 29, 2023
The
rubber
antioxidant
6PPD
has
gained
significant
attention
due
to
its
highly
toxic
transformation
product,
6PPD-quinone
(6PPDQ).
Despite
their
detection
in
urines
of
pregnant
women,
the
placental
transfer
and
developmental
toxicity
6PPDQ
are
unknown.
Here,
we
treated
C57Bl/6
mice
with
4
mg/kg
or
investigate
urine
excretion
transfer.
Female
male
exhibited
sex
difference
profiles
6PPDQ.
Urine
concentrations
were
one
order
magnitude
lower
than
those
6PPD,
suggesting
higher
bioaccumulation
In
from
embryonic
day
11.5
15.5,
showed
∼1.5–8
times
placenta,
embryo
body,
brain,
Using
vitro
dual-luciferase
reporter
assays,
revealed
that
activated
human
retinoic
acid
receptor
α
(RARα)
retinoid
X
(RXRα)
at
as
low
0.3
μM,
which
was
∼10-fold
detected
urines.
RXRα
1.2
μM.
These
results
demonstrate
exposure
risks
during
pregnancy
emphasize
need
for
further
toxicological
epidemiological
investigations.
