the times | Tuesday April 5 2022 7
health
that nobody neglects managing their
condition in the usual, mundane ways.
It’s the same for people with seasonal
allergies, Lewis says. No air purifier
will remove allergens and bacteria that
have settled on surfaces, so you’ll still
need to remove them with a vacuum
cleaner and to use an antibacterial
cleaning product to get rid of bacteria
lurking on door handles and phones.Are air purifiers essential in the city?
Urbanites should consider buying a
purifier if they live near a busy road
or train station, but don’t expect
miracles. Studies on them are often
carried out in very highly polluted
cities such as Beijing but, Lewis says,
“In most UK cities, even in central
London, the concentration of fine
particles that cause the biggest health
effects are typically ten times lower.
That doesn’t mean a purifier won’t
have benefits, but the gains will be
less significant.”Does a facemask provide some
protection for seasonal allergies?
As well as acting as a barrier that
entraps small particles such as
pollen, a facemask might also help
to reduce allergic rhinitis symptoms
by increasing the temperature and
humidity of the air breathed, says
Allergy UK. A PPE-grade mask such
as an FFP2 (called an N95 in the US)
that conforms to relevant standards
in the UK will filter more than 94-95
per cent of tiny particles and it has a
closer fit for added protection. A 2020
study from Israel showed that almost
half (42 per cent) of 301 nurses with
hay fever reported less sneezing and
other moderate symptoms when they
wore these types of facemasks for
a week.Will houseplants help to purify air?
Scientists have found little evidence
that they improve indoor air quality.
After a review of 12 studies that tested
196 plants over the past decade,
researchers at Drexel University in
Philadelphia concluded that while
plants will technically remove a tiny
amount of airborne toxins, you need
an “unfeasibly large number” of them
to make a difference.
“There is a tiny nugget of truth in
the belief that plants will help to clean
air,” Lewis says, but “the benefits have
been blown out of all proportion”.How to get cleaner air in your home
“The air quality in our homes is far
more variable than outdoor air,” Lewis
says. By far the biggest source of
pollutants in UK homes are aerosol
sprays and we should all aim to cut the
number of bottles and sprays in our
kitchen and bathroom cupboards by
half. “The chlorine released from the
bleach in strong cleaning products can
take your breath away,” he says. “But
almost all bottles and sprays produce
some chemicals that linger indoors.”Shouldn’t we just open a window?
On the advice of Allergy UK, windows
should be kept closed if you have hay
fever, particularly in the mornings,
when pollen is being released. If you
don’t suffer, Lewis says the best thing
most people can do to circulate fresh
air is to open a window.
“Because our outdoor air is mostly
pretty clean in the UK, unless you
live in an inner city, the air coming in
through a window is much cleaner
than the air inside your home. Just
opening a window by a tiny fraction
will improve air flow indoors.”New gadgets promise to clean the air that you breathe, both indoors and
outside. But is living in a bubble a good idea? Peta Bee asks the experts
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thetimes.co.uk/mensfitnessThere may be unforeseen downsides
to the technology. “People who use air
purifiers tend to seal up their windows
to ensure the filter works really well,”
Lewis says. “They then end up with a
home that is very low in particles,
which is a good thing, but with no
escape for other home irritants such as
the volatile organic compounds from
paint, furniture and cleaning products.”
He also questions whether the
home filters that collect the
chemicals are environmentally
sound. “When they are put in
the bin and dumped in landfill,
are we shifting a problem from
the air that will eventually
leach into soil and water?
We don’t know yet.
“For people with allergies,
those who live in highly
polluted areas and even the
rest of us during a pandemic
there are absolutely good reasons
to have cleaner air inside,” Lewis
says. “But the jury is still out on
whether it’s a good idea for all of us
to live in permanently air-filtered
homes and there’s the concern that
you emerge from your bubble into a
world that’s not filtered, presenting
an entirely new set of problems.”
Our microbiome defences develop
through a lifetime exposure to
airborne biological materials. “If you
asked me whether I’d bring up my
children from the age of zero to 18
years in a purified, high-filtered
environment, then I suspect I would
not. I don’t think I would be doing
them any favours in the long term.”An air purifier isn’t enough
According to Asthma UK, the benefits
of air purifiers come with a provisoBelow: the Zone
headphones by DysonThe mini version big enough only for
a bedroom or home office costs £449;
the Air Pro model for larger spaces
(up to 93 sq m) is more than £1,000.
Squeaky clean air will benefit those
with seasonal allergies, says Alastair
Lewis, professor of atmospheric
chemistry at the University of York
and chairman of the Defra Air Quality
Expert Group, because the avoidance
of airborne triggers such as pollen are
paramount in reducing symptoms.
“The ability to filter out pollen at
its height is of absolute benefit to
these people and, similarly, if
you suffer from very high
sensitivity to respiratory
irritants I suspect using a
Hepa-type filter will provide a
transformative improvement
to your quality of life.” But, he
warns, what’s sensible in some
environments can be turned
into “a marketing opportunity to
sell purifiers to 50 million people”.
For the rest of us the benefits are
less clear cut. Professor Alastair Hay,
a researcher in the University of
Bristol’s health protection research
unit, is investigating the usefulness of
air filters and purifiers in everyday life.
In some environments he suspects
they might have their uses — he and
his team are running a study in care
homes to find out if they reduce the
spread of infections — but a review of
evidence by his team produced mixed
results for use in the home, he says.
“A study we published last year in
the journal PLOS One showed that
there is good evidence they do clean
the air, but no evidence, one way or
the other, that this cleaning results in
generally improved human health at
least from an infection perspective.”N
ever have we been
more aware of the
air we breathe.
Sadiq Khan, the
mayor of London,
recently issued a
high air pollution
warning for the
capital and last week health chiefs
urged people to “take precautions”
such as wearing facemasks in shops
and on public transport in the wake
of the latest coronavirus wave.
These concerns coincide with the
increasing commodification of clean air
— the newest invention from Dyson is
a space-age set of headphones called
the Zone, which also purify the air by
filtering out “99 per cent of pollutants”.
Given that Allergy UK says most
of us spend 90 per cent of our lives
indoors, you may prefer to invest
in a high-end indoor air purifier.
Those using Hepa (high-efficiency
particulate air) technology have been
shown in tests by Nasa to capture
more than 99.97 per cent of tiny 0.3
micron particles the size of (or smaller
than) pollen, allergens, pollution and
smoke — and even some viruses. They
work by pushing air through a mesh
filter to get rid of airborne nasties and
are available at a range of price points,
from under £200 to more than £750.
If you have more to spend the
cutting-edge Molekule air purifiers,
newly launched in the UK, use a
patented Peco (photo-electrochemical
oxidation) technology that it is
claimed will not only collect but
destroy a wider range of tiny
pollutants including allergens, mould,
bacteria and viruses. With this device
you can control and track the air flow
in your home via an app — at a price.
Breathe in: here’s how to
improve your air quality