10 | New Scientist | 24 August 2019Chemistry HealthChris Stokel-Walker Clare WilsonAN ARMY of tiny magnetic coils
could one day dissolve the
microplastics lurking in our
waterways and oceans.
Microplastics from cosmetics
and household products can end
up in the ocean, where they are
ingested by marine life. Fishing
the particles out of water is
difficult, because they are so small.
Now Xiaoguang Duan at the
University of Adelaide in Australia
and his colleagues have tested
a way to turn microplastics
into carbon dioxide and water.The method may help avoid some
of the damage plastic does to the
environment, but it would emit CO 2.
The team put microscopic
metal coils into water along
with peroxymonosulphate ions.
A chemical reaction between the
two creates compounds called
radicals that break down the plastic.
Because the coils are magnetic,
they can then be removed by
waving a larger magnet over the
water. “They can be used multiple
times without significantly losing
their reactability,” says Duan.
He and his team put 80 millilitres
of water containing microplastics
from cosmetic products in a
pressurised container along with
the coils and peroxymonosulphate,
and heated the water to 120°C.
After 8 hours, the mass of
microplastics had halved (Matter,
doi.org/c9hv).
Duan hopes the process could
clean the outflows from water
treatment plants. This would stop
microplastics entering the ocean. ❚Tiny magnets
dissolve away
microplasticsCOULD the health risks from
booze be overblown? A study
has found that drinking low
levels of alcohol doesn’t appear
to cause cancer, and even heavy
drinking doesn’t cause breast
cancer – contrary to official
UK warnings.
The question of how much
alcohol it is safe to drink has
long been debated. Heavy
drinkers are more prone to
mouth and throat cancers, and
cirrhosis, where the liver starts
failing, but it was thought that
light drinking was safe or
possibly even good for you.
A growing number of studies,
though, have suggested that
even low levels of alcohol
consumption are linked with a
higher risk of cancer, including
that of the breast, oesophagus
and colon. In 2016, the UK
updated its alcohol guidelines,
cutting the maximum that men
should drink from 21 units a
week to 14, the same as that for
women – equivalent to six pints
of beer or just under one and
a half bottles of wine.
At the time, the UK’s chief
medical officer, Sally Davies,warned that there was “no safe
level of drinking” and said
whenever women had a glass
of wine they should weigh
up whether it was worth the
raised risk of breast cancer.
But the studies that showed
these risks looked only atcorrelations between drinking
levels and cancer rates, and
couldn’t determine if alcohol is
the cause. Something else could
be responsible, because people
who drink more also tend to
smoke more, have lower
incomes and have unhealthy
lifestyles in various other ways.
Fotios Drenos at Brunel
University London and his
colleagues got around this
problem by analysing which
variants of genes people
have. This is determined
at conception and can’t be
affected by lifestyle and habits.
They focused on a gene
variant of an enzyme made in
the liver that leaves people sick
and dizzy after relatively little
alcohol. People can have two,
one or no copies of this variant.Those with more copies
unsurprisingly tend to
drink less.
Drenos’s team looked at
about 300,000 people taking
part in the UK Biobank study,
which has sequenced people’s
genes and periodically surveys
their health and behaviour.
It has now tracked participants
for up to 13 years.
Women who were genetically
predisposed to drink more,
because of a lower amount of
the liver enzyme, didn’t have
a higher rate of breast cancer.
In fact, there was no correlation
between genes and the
likelihood of cancer studied
when looking at those who
drink less than 14 units a week
(medRxiv, doi.org/c9j3). The
team studied breast cancer
in women and tumours of
the mouth, throat and the
rest of the digestive system.
It isn’t a clean bill of health:
in people who went over
the 14-unit threshold, those
genetically predisposed to
drink more did have a higher
rate of throat cancer. “It’s more
biologically plausible that heavy
drinking causes these tumours
as alcohol comes into contact
with the throat,” says Drenos.
The team also confirmed the
lack of a link to breast tumours
in another study of genes and
cancer, called COGS.
The findings aren’t the final
word, says Frank Dudbridge at
the University of Leicester, UK,
because cancer risks could be
too low to be revealed this way.
“It’s difficult to find a small
effect unless you have really
big data sets,” he says.
Emmert Roberts at King’s
College London points out that
drinking can cause harms apart
from cancer, such as increased
risk of depression and anxiety. ❚Alcohol may not increase
your risk of breast cancer
KLAUS VEDFELT/GETTYNews
Links between alcohol
and breast cancer may
be overturned“ Women genetically
predisposed to drink
more didn’t have higher
rates of breast cancer”Microplastic
particles are
much trickier
to remove from
water than larger
plastic pollutionANGEL FITOR/SCIENCE PHOTO LIBRARY