Health & Science NEWS 21
Two masks much better than one
Wearing two masks at the same time—or
just fitting a single mask more tightly—sub-
stantially reduces the risk of Covid-19 infec-
tion, reports The Wall Street Journal. In a
series of experiments using dummy heads
and aerosol-generating machines, research-
ers from the Centers for Disease Control
found that wearing a three-ply cloth mask
over a three-ply surgical mask blocked as
much as 92.5 percent of particles from a
cough. That’s more than double the pro-
tection offered by a surgical mask alone
(42 percent) or a cloth mask (44.3 per-
cent). In another experiment, two dummies
were placed 6 feet apart to test different
masking strategies. When one “breathing”
dummy didn’t wear a mask and the other
wore a tightly-fitted single surgical mask—
researchers tied knots in the ear loops and
tucked the sides into the face—the mask
wearer’s aerosol exposure was reduced by
64.5 percent. When the other dummy was
similarly masked, that number went up
to 95.9 percent. The researchers don’t yet
know whether the performance of single
or double masks is different against the
new, more contagious Covid variants now
spreading in the U.S. “It’s the same virus,
so the measures should work,” says John
Brooks, chief medical officer of the CDC’s
Covid-19 response. “What we don’t know
is how effectively they will work.”More warming, more pollen
If you think your pollen allergy is blowing
up earlier every year, you’re not mistaken—
and climate change might be to blame. A
new study has found that rising tempera-
tures have both worsened and lengthened
the pollen season across North America.
The researchers examined three decades’
worth of pollen-count data from 60 moni-
toring stations across the continent. They
found that pollen season now starts an aver-
age of 20 days earlier than in 1990, lasts 10
days longer, and involves 21 percent more
pollen. The biggest increases were recorded
in Texas and the Midwest, and from trees
rather than grasses and other plants. The
researchers calculated that climate change
accounts for about half the increased length
of pollen season and 8 percent of the higher
pollen count. Warmer temperatures keep
plants and trees producing pollen for a
longer period and increase pollen concen-
trations in the air. “Climate change isn’t
something far away,” lead author William
Anderegg, from the University of Utah,
tells USA Today. “It’s already here in every
spring breath we take.”Black coffee for the heart
Coffee may help reduce the risk of heart
failure, but only if it’s black. Researchers
examined data from three major long-term
health and diet studies involving a total
of 21,000 Americans. Across two of the
studies, people who drank at least one cup
of joe a day had a 5 percent to 12 percent
lower risk of suffering heart failure than
those who didn’t drink coffee at all. The
other study found no differences among
those drinking one cup a day, but a roughly
30 percent decreased risk for those drinking
two or more. The apparent benefits were
not seen among those who drank decaf-
feinated coffee; in fact, they had a higher
risk of heart failure. The studies were done
only for black coffee— adding dairy, sugar,
flavors, or nondairy creamer might negate
any possible heart benefits. “Coffee and
caffeine are often considered to be ‘bad’
for the heart,” senior author David Kao,
from the University of Colorado, tells
CNN.com. “The consistent relationship
between increasing caffeine consumption
and decreasing heart failure risk turns that
assumption on its head.”Ne
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Double masking doubles the protection.Scientists have discovered what they
think is the world’s smallest reptile:
a chameleon so minuscule it
can perch on a human fingertip.
Roughly the size of a sunflower seed,
Brookesia nana was spotted dur-
ing an expedition in northern
Madagascar. Researchers found
a male with a 0.53-inch-long
body; nose to tail, it was
0.85 inch. They also found
a female, a relative giant
with an overall length of
1.14 inches. A CT scan on the
female revealed that it was
carrying two eggs, confirm-ing it was an adult. The male’s genitals
were almost one-fifth of its body size—
possibly to enable it to mate with larger
females. Confirming that Brookesia nana
is indeed the smallest of the world’s
roughly 11,500 reptile species will
require more specimens to be
found. But spotting them is no
cakewalk. “You really have
to get down on your knees,”
lead author Frank Glaw,
from the Ba var ian State
Col lec tion of Zool ogy in
Munich, tells the Associated
Press. “They are obviously
camouflaged and they move
very slowly.” And, of course,
they’re very, very small.The world’s teensiest reptile?
While Covid-19 continues to infect tens
of thousands of Americans every day,
another usually rampant respiratory virus
is almost nowhere to be seen: influenza.
Since the fall, about 800,000 lab flu tests
have been reported to the Centers for
Disease Control and Prevention. Only
1,500 have come back positive, or 0.2 per-
cent, an infection rate 100 times lower
than it was 12 months ago. In a typical
year, hundreds of thousands of Americans
are hospitalized with the flu, but this sea-
son’s tally was only 155 as of last week.
And only one child has died from the flu
so far this year, compared with 78 at thispoint in 2020. Scientists say the radical
behavioral changes that Americans have
made during the pandemic—such as
social distancing, mask wearing, and con-
stant handwashing—are largely responsi-
ble for this unusually quiet flu season. “Flu
just tends to be a lot less transmissible
[than a coronavirus], which means it’s eas-
ier to suppress,” Shweta Bansal, a disease
ecologist at Georgetown University, tells
The Atlantic. Travel bans have also helped
quash influenza, which is often seeded in
the Northern Hemisphere in fall by travel-
ers from the Southern Hemisphere. But
influenza could still make a late-seasonreturn: There’s some evidence infections
are increasing in parts of Asia that have
eased anti-Covid precautions. “We may
not be out of the woods yet,” says Bansal.Missing: One flu season
Covid restrictions have quashed the flu virus.A miniature male