We've known for a long time that outdoor air pollution can have a variety of adverse health effects, and now we're becoming increasingly aware of indoor air pollution.
We spend most of our time indoors, and much of that at home, where our everyday activities (such as spraying aerosols) and even the things that we own, all contribute to concentrations of potentially harmful indoor pollution.
Read on to find out which products can help improve the quality of your air at home, when to consider buying one, and what to look for.
If you suffer from allergies, a good air purifier can help you by trapping pollutants such as dust and pollen particles. Some come with carbon filters, designed to also capture gases.
Air purifiers aren't a perfect or complete solution to the problem of air pollution, and it's a market that's still developing as more information comes to light. It's currently impossible, for example, to say which are most effective at tackling gases caused by traffic pollution coming in through an open window. However, you can use our to find one that does a great job of trapping dust, pollen and smoke particles.
Many air purifiers come with features that make them easier to use, such as smart connectivity. Smart functions let you control the air purifier from your smartphone and/or check pollution levels in your home, and auto settings, which prompt the air purifier to spring into action when a pollution levels rise (you've just sprayed deodorant, say).
The fact that an air purifier has lots of features, or comes from a famous brand, doesn't mean it will do a good job, as our testing as shown.
At the very least, though, look for one with a HEPA (high efficiency particulate absorbing) filter. Other filters - including ones with names like HEPA-type filter - aren't held to the same European Standards as HEPA filters.
Air purifiers aren't cheap, and some go up to £700.
You don't need to spend as much as that, though: a popular hi-tech model is the ElectriQ EAP500C (£250, pictured below), which has a HEPA filter, a carbon filter, four fan speeds, an automatic mode, a night mode (which reduces the noise and power so it doesn't disturb your sleep) and an LED indicator which changes colour depending on the air quality in the room. Read our review to see what we thought of it.
Very small (often cheap) air purifiers won't do much to purify your room. You might have seen some tiny plug-in air purifiers such as the , for sale and been tempted on the basis that they're cheap and probably better than nothing. Air purifiers need a fan to draw air in, and a tiny device like this can't house a fan big enough.
Unsurprisingly, given increasing public awareness of air pollution, we're seeing more air monitors on the market.
Some, such as the (£137) from manufacturer NotAnotherOne (pictured above), are designed to clip on to your bag or belt so you can take it out and about with you. Others, such as the (£79), are exclusively for the home.
An air monitor sends you real-time information about the pollution levels in your vicinity: harmful gases, volatile organic compounds (VOCs) such as acetone, methanol, benzene, ethanol, xylene and formaldehyde, and PM 1, 2.5 and 10 (particulate matter pollutants), in the case of the Atmotube Pro.
It sends all this data to the Atmotube app on your phone via Bluetooth. You can then review your data to see when in the day you were exposed to pollution and adapt your routines accordingly: walking through a park rather than via a busy road, for example.
We think they're a great concept, but obviously the more flexibility you have to change your lifestyle habits (often tied to how well off you are), the more benefit you'll get from an air monitor.
If you know someone with an air monitor, try borrowing theirs for a few weeks rather than buying your own.
If you're buying an air monitor, consider weight (the heavier it is, the more of a burden it'll be to have it clipped to your bag) and how often it needs charging (especially if you already have a million other devices to charge each day).
Portable air monitors cost in the region of £100 to £200. You can buy cheaper home air monitors, such as the Airthings Wave Mini (but if you're buying a home air monitor, you may want to save that money for a purifier for your home instead).
If there are water stains on your walls or ceiling, mould spores in your bathroom or condensation on your windows, or your home feels musty or smells humid, it's time to buy a dehumidifier.
Indoor dampness can lead to asthma and other respiratory problems, make it harder for you to dry your clothes in winter, and provide a perfect breeding ground for clothes moths, dust mites, fleas and cockroaches. A dehumidifier can stop damp in its tracks.
If you've got a serious damp problem, however, call in a professional. The longer you leave it, the more expensive it will be for you to deal with.
There are two types of dehumidifier - refrigerant (sometimes called compressor) and desiccant - and these work differently.
If your damp problem is in a room that's generally heated, a refrigerant model will often be best, although we have found some desiccants that work just as well.
If your damp problem is in a cold room, such as an unheated garage, go for a desiccant.
If you're short on space, look for one that's compact and lightweight (but bear in mind that you'll need to empty the tank more often). The (£200, below) is smaller and lighter than many dehumidifiers we've tested: find out whether or it's any good.
You don't need to specifically look out for one with a clothes-drying feature, as all dehumidifiers can be used for this.
Dehumidifiers start at about £70 and go up to more than £300. No model costing less than £130 is currently a Best Buy.
If your damp problem is very mild (you've noticed a bit of condensation and think it can't hurt to remove it, say) you can buy moisture absorbers, aka damp traps, from places like Poundland. These are little trays containing crystals that draw moisture in and eventually turn into a salty liquid. They can't help with big damp problems, though.
While air purifiers and air monitors are nice-to-haves, and we'd recommend buying one if you feel concerned about the air in your home, a carbon monoxide (CO) alarm is essential.
CO poisoning can be deadly: it stops your blood carrying oxygen, causing the body's cells and tissue to fail and die.
It has no smell or taste, and its symptoms (dizziness, shortness of breath, tiredness and confusion and feeling sick) can easily be mistaken for flu or food poisoning. The NHS says that 60 people a year in England and Wales die from CO poisoning.
If you own a fuel-burning boiler (eg gas, LPG, oil, wood), you must have a CO alarm in every room where fuel is burned.
If you live in a house that's powered entirely by electricity, you won't need a CO alarm.
Very worryingly, there are plenty of CO alarms on sale that just don't work. We've had to label a fifth of those we've tested Don't Buys.
It's definitely worth spending more for a safety product. You can pick up a CO alarm cheaply online for £10 or less - but the chances are it won't work. You're much more likely to get one that works if you pay at least £20.
Only buy from a brand that's widely available in shops such as Argos, B&Q, Currys PC World, John Lewis, Homebase, Screwfix and Wickes. Reputable firms like these only stock alarms from well-known companies.
We'd also recommend avoiding patch CO detectors, which simply change colour. You could pick up a pack of two for a fiver - which sounds temptingly cheap - but unless you're going to be looking at it all day (and night), you'll have no idea when there's a problem. Buy one that sets off an alarm you can hear instead.
Vacuuming often helps keep your home clean from dropped food and shed skin cells, as well as moths, fleas, firebrats, fleas, beetle grubs, bed bugs and other insects that love undisturbed carpets and rugs (lovely!).
It's important to buy one with good allergen retention or you risk all the allergens you've just vacuumed up leaking back out again. That can happen when the internal system is poorly sealed or the dust filters aren't working as they should do.
Our reviews can also point you towards one that's easy to manoeuvre and which glides easily over a range of surfaces. If it's too cumbersome, you're not going to want to vacuum often.
And, of course, you'll need one that's good at its basic job of sucking up dirt. Our reviews can also help you find one that's great at picking up small items that you can barely see, such as fine dust, and larger items, such as rice.
The Dyson Light Ball Multi Floor vacuum cleaner (£199, below) is a really popular model and has a redesigned floor-head that should tackle large and small household debris. It comes with a long extendable wand for reaching hard-to-vacuum places like ceilings and lampshades too.
Some of the easiest ways to reduce air pollution in your home won't cost you any money.