It’s easy to think about air purifiers as being something that people in other countries need. Cities like Delhi, where the air quality frequently gets as bad as 349 PM2.5, which is significantly worse than the WHO recommended 10. In comparison, the highest Melbourne got in the last 48 hours was 14.5 PM2.5, with the air quality normally staying well below 10.
So, with that in mind, do we really need air purifiers? The answer depends on a lot of factors.
Obviously, we need them during major bushfire events, like the horrible summer we just had. But outside that, a US study recently found that reducing the current US guidelines of 12 PM2.5 (which means 12 parts per million of particles roughly 3% the diameter of a human hair) to 10 PM2.5 would save more than 140,000 lives over a decade. That’s a difference of 2 particles per million, which shows how insidious these pollutants, usually caused by traffic, industrial burning and bushfires, can be.
A study out of the University of Sydney found there is no safe level of PM2.5, and that 90% of cardiac arrests that occurred outside hospitals happened on days when the air quality was under 25 PM2.5. An elevated amount of PM2.5 particles are particularly hazardous for people over 65 and asthma sufferers, who are really not having a great year when it comes to major risks to their health.
Now that we know that, the next thing is to work out how bad the air is in your home, which comes down to how often do you cook and/or burn things? Candles, toast, or anything, really. How effective is the rangehood over your stove (probably not very)? Do you suffer from hayfever? Do you live in the city or an industrial area, or in the middle of a paddock?
Dyson recently analysed the filter from my Pure Hot+Cool Link air purifier and discovered that while I thought the air in my home was super clean, it’s actually got a lot going on. My apartment is relatively small and in the middle of the city, so I don’t really do a lot of arts and crafts and certainly don’t spray pesticides. Yet my measurements for 1,4 Dichlorobenzene (disinfectants, pesticides, mothballs), Hexane (gasoline, stain removers, spray adhesives) and Stryene (packaging, plastic, latex) were a little higher than usual. The filter also showed evidence of mould and pet dander. We don’t have any pets. So that was disconcerting.
There’s been surprisingly little research done into indoor air quality, or the long-term health effects of many of the chemicals found indoors. But, according to the CSIRO, the adverse health and environmental effects of poor indoor air quality cost up to $12 billion in 1998.
If you’re concerned, but not quite concerned enough to get a purifier, Dyson had this advice on how to improve air quality in your home:
- Use natural cleaning products to reduce the amount of VOCs (volatile organic compounds) in the air.
- Keeping your surfaces free of dust and pet hair.
- Light candles and incense, and diffusing essential oils in moderation (or, preferably, not at all).
- Consider going outside to enjoy the “fresh air” if you live near a busy road, train line, or other pollutant, instead of letting the NO2 and SO2 gases into your home.
If you think you fall into a risk category, or know that there are some things around your home that might make your air a little less clean, then these are the things to look for when buying an air purifier:
- A machine with fully sealed filters, so the air is forced to be filtered, rather than giving it an escape route.
- Both a HEPA filter and an activated carbon filter so it can catch both particles and gas.
- A fan. Having clean air coming out of the purifier does nothing if you don’t eventually breathe it in. If the purifier has a fan it’ll be able to more evenly distribute the freshly clean air around the room.