19 October 2019 | New Scientist | 2725 years ago, New Scientist
was celebrating a milestone in
eradicating the scourge of polioIT WAS a rare example of a
straight-up good news story.
“Polio has been eradicated
in the western hemisphere,
officials at the Pan American
Health Organization declared
last week,” we wrote in our
8 October 1994 issue.
Polio is a viral disease that
is typically transmitted by the
ingestion of faecal matter, often through infected
water supplies. If the virus enters the central nervous
system, it can cause muscle weakness and paralysis,
and sometimes death or long-term disabilities.
Effective polio vaccines were first developed in
the 1950s, but a coordinated global fight to eradicate
the disease began in earnest in 1988. The disease was
officially eliminated in China, Australia and 34 other
western Pacific countries in 2000. Europe was declared
polio-free in 2002.
“The last known polio case in the Americas was a
Peruvian boy called Luis Fermin who contracted the
virus in August 1991,” we wrote. Models suggested
that if the virus were still circulating there, at least one
case of polio-induced paralysis would have occurred
in the following three years. There had been none.
Other animals can’t carry polio, so once the world’s
human population is finally purged of it, there will be
no reservoir from which the natural virus can emerge
to reinfect us. Afghanistan and Pakistan are the last
remaining regions with wild polio cases; there are
fewer than 100 a year.
Will the scourge of polio now vanish from
human memory? Probably not. For a start, there is an
attenuated strain present in the popular and effective
trivalent oral polio vaccine itself. This strain can persist
in the environment and regain the ability to cause polio.
Such a strain was probably responsible last month for
the first cases of polio recorded in the Philippines since
the virus was declared eradicated there in 2000.
We discussed one ingenious solution to this problem
in March 2017, when we reported on some nifty gene
editing that resulted in a live vaccine with a lower risk of
mutating into a virulent form. More worrying, perhaps,
is that a team of researchers in 2002 built the polio
virus from scratch in the lab, using nothing more than
genetic sequence information from public databases
and readily available technology. The price of liberty
from polio will be eternal vigilance. Simon IngsTo find more from the archives, visit
newscientist.com/old-scientistViews From the archives
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Send letters to New Scientist, 25 Bedford Street, London
WC2E 9ES or [email protected]; see terms at
newscientist.com/lettershide their vulnerability. One,
PM Consultants in Portland,
Oregon, closed suddenly in
July after an attack. Educating
management is necessary, but
we need a concomitant emphasis
on “you get what you pay for”.
It isn’t necessarily good
just because it is green
24 August, p 6
From Hugh McAdams,
Glasgow, UK
You report on CityTrees – moss
walls from Berlin-based firm
Green City Solutions. Glasgow
installed two on busy streets in
- I calculate that they removed
less than 0.02 per cent of the city’s
pollutants each year. They have
now disappeared.
As Scully notes, researchers at
the Netherlands Organisation for
Applied Scientific Research found
that eight moss walls installed in
Amsterdam failed to reduce the
concentration of pollutants. The
makers of the trees don’t make
any outlandish claims – so why
have 50 been installed in European
cities, costing about $60,000 each?
How well do wind tunnels
simulate mountain air?
14 September, p 14
From Sandy Henderson,
Dunblane, Stirling, UK
Chelsea Whyte reports that
wind-tunnel experiments on
bar-headed geese show their blood
cools in low-oxygen conditions,
simulating those they face
crossing the Himalayas. Cooler
blood can carry more oxygen.
Did the researchers recreate
the low pressure and temperature
that the birds would encounter
7000 metres up? At low pressure,
it is harder for the wings to
transfer heat to the passing air
and cool the blood. That might be
balanced in real life by the greater
temperature gradient at altitude.The editor writes:
The experiment didn’t mimic
pressure or temperature at high
altitudes, just oxygen levels. But
if the birds’ blood running cold
makes them more efficient at sea-
level pressures, the effect is likely
to be even stronger at altitude.I am not so happy with Ola
Rosling’s cheery statistics
7 September, p 46
From Arne Maus,
Nesoddtangen, Norway
I agree with Ola Rosling that we
should base our views on facts,
but I see problems with the
statistics he presents.
One graph shows the risk
of dying in a plane crash as one
per 10 billion passenger miles.
No flights are 1 mile long and
most of the risk is at take-off
and landing. It would be better
to give the risk per flight.
Another states that the fraction
of Earth’s surface in protected
reserves increased from 0.03 per
cent in 1900 to 14.7 per cent in- This says only that certain
nations are trying to save some
of their land.
Pristine forests and nature
are clearly suffering as the
Amazon, parts of Indonesia and
elsewhere are burned to make
way for farmland.^ ❚
For the record
❚ The photograph we used to
illustrate our report on climate
change increasing the risk of heavy
rainfall and storm surges in coastal
areas was of Mytholmroyd, West
Yorkshire, UK, which has flooded
but is around 90 metres above sea
level and a 70-kilometre walk from
the coast (28 September, p 18).