英语四级阅读材料(世界大城市正向大区域化发展) 本文关键词：英语四级，大城市，区域，材料，发展
英语四级阅读材料(世界大城市正向大区域化发展) 本文简介：青年人英语四级考试网:http://www.qnr.cn/waiyu/cet4/本篇阅读材料“孕妇暴露于受污染空气将增加孩子发胖几率”选自《时代》（原文标题为：ExposuretoAirPollutioninPregnancyMayBoostChancesofObesityinKids2012.4.
英语四级阅读材料(世界大城市正向大区域化发展) 本文内容：
青年人英语四级考试网:
http://www.qnr.cn/waiyu/cet4/
本篇阅读材料“孕妇暴露于受污染空气将增加孩子发胖几率”选自《时代》
（原文标题为：Exposure
to
Air
Pollution
in
Pregnancy
May
Boost
Chances
of
Obesity
in
Kids
2012.4.17）
It
s
easy
to
blame
parents
when
young
children
gain
too
much
weight,but
the
latest
research
suggests
that
certain
obesity
risk
factors
are
out
of
Mom
and
Dad
s
control.
In
a
study
published
this
week
in
the
American
Journal
of
Epidemiology,scientists
at
the
Mailman
School
of
Public
Health
at
Columbia
University
found
that
exposure
to
air
pollution
during
pregnancy
may
be
associated
with
a
greater
chance
of
having
heavier
kids.
Andrew
Rundle,an
associate
professor
of
epidemiology,decided
to
study
air
pollution
because
he
was
curious
about
the
role
that
environmental
chemicals
known
as
endocrine
disruptors
—
compounds
that
include
BPA,phthalates
and
parabens
—
play
in
determining
weight.
Endocrine
disruptors,which
mimic
naturally
occurring
hormones
like
estrogen
in
the
body
and
interfere
with
some
developmental
and
metabolic
functions,are
also
found
in
air
pollution;
animal
studies
have
shown
that
mice
exposed
to
estrogen-like
compounds
in
air
pollution
gain
more
weight
than
unexposed
mice.
Rundle
and
his
colleagues
set
about
tracking
air
pollution
exposure
in
702
women
in
their
third
trimester
of
pregnancy,by
equipping
them
with
air
monitors
tucked
into
backpacks.
The
women
wore
the
backpacks
for
48
hours,except
while
sleeping
or
showering,measuring
levels
of
polycyclic
aromatic
hydrocarbons
（PAHs）,endocrine-disrupting
chemicals
found
in
cigarette
smoke
and
car
exhaust.
The
women,who
were
recruited
from
the
university
hospital
s
New
York
City
clinics,lived
in
the
neighboring
area,including
the
Bronx
and
northern
Manhattan
—
areas
that
have
heavy
car
traffic
but
are
not
known
to
have
unusual
amounts
of
industry-related
pollution.
Children
born
to
mothers
with
the
highest
PAH
levels
during
their
third
trimester
had
a
79%
greater
risk
of
becoming
obese,compared
with
children
born
to
moms
with
the
lowest
PAH
levels.
By
age
7,the
risk
was
even
higher
—
more
than
2.25
times
greater.
Previous
studies
have
linked
air
pollution
to
increased
risk
of
heart
disease
and
stroke,and
Rundle
s
colleagues
have
shown
that
PAH
exposure
during
pregnancy
can
also
increase
the
risk
of
behavioral
problems
in
children
by
age
5
and
7,but
this
is
the
first
study
to
link
the
pollutant
to
obesity.
“It
s
a
fairly
big
effect,”
says
Rundle.
“Obesity
is
really,really
complicated,and
there
are
different
things
pushing
us
in
the
wrong
direction
in
terms
of
energy
consumption
and
physical
activity.
I
think
we
have
to
embrace
the
idea
that
the
obesity
epidemic
is
not
just
about
you
and
me
making
personal
choices
that
are
not
good
for
us,or
moms
making
bad
choices
for
kids.
It
s
a
far
more
complicated
problem
than
that,and
environmental
chemicals
may
play
a
role
as
one
piece
of
the
problem.”
Not
all
of
the
children
whose
moms
were
exposed
to
the
higher
levels
of
PAH
became
obese,but
a
significant
proportion
of
them
did,and
the
connection
between
PAH
exposure
and
obesity
remained
strong
even
after
Rundle
s
team
adjusted
for
other
factors
that
could
influencing
factors,including
the
mother
s
socioeconomic
status,her
income,and
the
median
household
income
of
the
neighborhood
in
which
the
mothers
lived.
“We
went
through
a
long
list
trying
to
imagine
all
the
reasons
that
could
bias
the
relationship
or
explain
it
away,”
says
Rundle.
“And
after
months
and
months
of
healthy
skepticism,we
came
to
the
point
of
realizing
that
the
data
looked
really
solid.”
To
ensure
that
the
obese
children
s
excess
weight
was
due
to
fat,not
added
bone
or
muscle,the
researchers
measured
body
fat
composition
in
a
subset
of
453
children;
they
found
that
fat
almost
exclusively
accounted
for
the
children
s
heavier
weight.
That
corresponded
to
animal
studies
as
well,and
could
hint
at
how
the
PAHs
are
contributing
to
obesity
—
by
disrupting
how
fat
cells
are
formed
and
develop
during
childhood.
Normally,most
of
the
fat
cells
adults
have
are
generated
during
the
first
year
of
life,beginning
in
utero;
weight
gain
results
when
these
existing
fat
cells
swell
in
size,not
in
number.
But
exposure
to
potential
endocrine
disruptors
like
PAHs
could
interfere
with
the
normal
development
of
fat
cells
in
infancy,and
lead
to
an
increase
in
fat
cells
from
an
early
age.
It
s
hard
to
avoid
air
pollution,particularly
for
expectant
mothers
living
in
densely
populated
cities.
But
it
is
possible
to
avoid
the
worst
sources
of
PAH
exposure,such
as
cigarette
smoke.
Avoiding
smoking
while
pregnant
and
asking
friends
and
family
to
refrain
from
lighting
up
can
help,but
Rundle
says
it
s
time
that
more
ubiquitous
sources
of
air
pollution
also
be
recognized
by
public
health
experts
and
mothers
as
potentially
long-term
health
hazards.
Although
Rundle
s
study
did
not
examine
whether
a
child
s
exposure
to
PAHs
in
his
first
five
years
of
life
could
have
been
the
driver
of
obesity
rather
than
the
mother
s
prenatal
exposure,the
findings
still
provide
hard-to-ignore
evidence
that
breathing
in
polluted
air
could
have
health
effects
that
may
last
a
lifetime.
【重点单词及短语】
be
associated
with
与……有关
be
curious
about
对……好奇的
endocrine
disruptors
环境激素
interfere
with
干扰，干涉；妨碍；触动或弄坏；乱动；与……抵触
set
about
着手；开始做
tuck
into
藏进
polycyclic
aromatic
hydrocarbons
（PAHs）
【化】多环芳香烃，分子中含有两个或两个以上苯环结构的化合物，是最早被认识的化学致癌物。
explain
sth.
away
为某事搪塞；把……解释过去
account
for
对…负有责任；对……做出解释；说明……的原因
correspond
to
符合；相当于
hint
at
暗示；对……暗示
health
hazards
健康危害
Question
time:
1.
What
kinds
of
research
did
people
do
up
to
now
according
to
the
introduction
in
the
passage?
2.
How
to
avoid
the
worst
sources
of
PAH
exposure?
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