When it is bitterly cold outside the temptation is to bunker down at home, block out any draughts and do everything possible to stop that expensive heat escaping.
But this means indoor air pollution tends to be particularly bad at this time of year; more than three times worse than outdoor air pollution, according to a 2019 study by the UK air pollution campaign, Clean Air Day.
One of the main sources of indoor air pollution is VOCs, volatile organic compounds, which are chemicals that leach out of cleaning products, furniture and paint.
They linger in the air and we breathe them in — this can lead to headaches, as well as irritation to our eyes, nose and throat.
If your house is poorly ventilated, there is also the risk of mould, which releases spores into the air that can trigger respiratory infections, allergies and asthma.
There is evidence that plant leaves can absorb indoor air pollution, while microbes in the soil also break down pollutants
if you have pets, poor ventilation puts you at risk from pet dander, which can also provoke allergic reactions
And if you have pets, poor ventilation puts you at risk from pet dander, which can also provoke allergic reactions (more on this later). The worst villain, however, is indoor fires.
A friend who has a log burner in her sitting room told me that buying one was the best thing she had ever done.
I didn’t have the heart to explain that even a modern log burner emits huge amounts of tiny carbon and tar particles, called PM (particulate matter), which are so small they get into our lungs, triggering inflammation, and into our brains where they’ve been linked to an increased risk of dementia.
According to the Department for Environment, Food & Rural Affairs, wood burners produce more of this dangerous form of air pollution than all of the UK’s road traffic put together.
Now a new study, by Manchester University and Imperial College London, will investigate just how bad PM is compared with other forms of indoor air pollution.
Researchers have recruited 13 brave volunteers, who will be monitored as they sit in a small, sealed lab breathing in a different air pollutant at a time, for an hour.
These include exhaust from a diesel engine, wood smoke, fumes from cleaning products and the fumes produced by frying pork chops (frying generates lots of PM).
Although there are only 13 people in this experiment, it is the biggest and most ambitious of its kind ever undertaken.
The researchers are interested in the impact air pollution has on the brain, so volunteers will do cognitive tests before and after; they’ll also have regular blood tests to check for signs of damage to brain cells.
I feel for the volunteers — a few years ago I did something similar, though in my case the researchers were interested in the impact of outdoor air pollution on my heart.
They put me in a room while a truck’s diesel engine pumped fumes into the room for an hour.
Breathing in those fumes made my blood pressure immediately shoot up, and the scientists told me something in the diesel (presumably PM) made my arteries stiffen and my blood thicken.
While my blood pressure returned to normal after two hours, it gave me a shocking insight into what invisible pollution can do.
Here are a few things you can do to reduce your own exposure to indoor air pollution.
OPEN WINDOWS — IF NOT NEAR BUSY ROAD
Opening windows to let in fresh air is generally a good idea — but if you live within a mile of a busy road then, according to the Building Engineering Services Association, opening a window can actually be counterproductive.
So you might want to check websites that give you information about local pollution levels — and avoid opening windows if you live near a busy road, particularly during the winter when air pollution from traffic is often trapped at ground level by cold air.
Avoid opening windows if you live near a busy road, particularly during the winter when air pollution from traffic is often trapped at ground level by cold air
SWITCH ON EXTRACTOR FANS WHEN COOKING
If you have an extractor fan or hood, use them when you are cooking — regardless of what you’re cooking or for how long. They’re a more effective way to get rid of cooking fumes than opening a window.
STEER CLEAR OF AIR FRESHENERS
It is a good idea to avoid using synthetic air fresheners and scented candles as these release lots of VOCs, which can irritate the eyes, nose and throat, and are particularly bad for those with asthma.
Try to find chemical-free products where possible, as these produce fewer VOCs.
INVEST IN A DEHUMIDIFIER
damp and mould are bad for your lungs, and they often appear at this time of year because of condensation and a lack of ventilation.
If you get a lot of damp, invest in a dehumidifier to reduce the humidity that encourages mould to flourish.
The best way to keep levels down is to vacuum frequently and give your pet a regular wash
CLEAN REGULARLY
CARPETS can trap dust and, if you have pets, lots of pet dander — tiny flecks of skin which come off cats and dogs that can trigger allergies.
The best way to keep levels down is to vacuum frequently and give your pet a regular wash.
BUY HOUSE PLANTS
There is evidence that plant leaves can absorb indoor air pollution, while microbes in the soil also break down pollutants. Dr Tijana Blanusa, a plant scientist at the University of Reading, advises going for hardy specimens, such as Snake plant, Spider plant or Peace lily.
And finally, if you do have a wood-burning stove or open fire, then it is best to use it sparingly.
You could also invest in smokeless fuel, which emits up to 75 per cent less PM.
One of the key roles of our gut microbiome, the trillions of microbes that live inside us, is to protect us from dangerous invading microbes. Now we know how they do it: in lab-based experiments, researchers at Oxford University showed that the main way our microbiome protects us is with ‘nutrient blocking’ — i.e. starving out any invaders. This seems to be a collaborative effort between different microbes, and could explain why having a diverse microbiome is so important for our health. So keep eating those greens!
All of us have secrets — and generally keep them to ourselves because we fear being judged harshly.
But a new study suggests such fears are overblown. Researchers at the McCombs School of Business in the U.S. looked at the results of a series of experiments where people were encouraged to tell strangers, friends and family some potentially shameful secrets, such as having had an affair.
While the volunteers assumed that revealing their secrets would make them seem less trustworthy, this study found the opposite: it made them appear more honest and open; and others were more charitable than expected. So perhaps it’s time to confess all…
Could being hypnotised help banish chronic pain?
Most of us think of hypnosis as a bit of fun (‘look into my eyes, into my eyes’). But there is evidence that hypnosis can be effective for treating medical conditions, including pain, irritable bowel syndrome and insomnia.
The trouble is, it only works in some people — research suggests just 15 per cent of us are ‘highly hypnotisable’.
A few years ago I was ‘hypnotised’ by a trained professional and then, under his guidance, I tried pushing a needle through the fleshy part of my hand. ‘Imagine it is sliding through your flesh,’ he intoned, ‘and yet you feel no pain.’ He was wrong, it hurt like hell. Hypnosis also hasn’t improved my insomnia. So wouldn’t it be great if I could be made more suggestible?
Scientists are now looking at how to prolong this effect, to make hypnosis a viable treatment for chronic pain
Now a study by Stanford University in the U.S. has shown that you can make people more hypnotisable — and it takes just 90 seconds, with a technique called transcranial magnetic stimulation.
With this, high-tech paddles (that look like table tennis bats) are applied to your scalp to deliver electrical pulses to your brain. The Stanford researchers, who had previously used this approach to treat depression, recruited 80 volunteers who did not respond to hypnotism — one group had 90 seconds of the brain stimulation, while the others received a sham treatment.
Results showed that patients given the real treatment were far more hypnotisable, though the effect wore off after a couple of hours. The scientists are now looking at how to prolong this effect, to make hypnosis a viable treatment for chronic pain.
Hypnotherapy is not routinely available on the NHS: your best bet is to find a practitioner through the National Hypnotherapy Society.