For someone living in a city with reasonably clean air and no smog problem, does filtering the air in their living space provide any long-term health benefits?
This is Thomas--founder of Smart Air. Interesting question. I've seen plenty of studies showing the effects of air pollution on people's health (the study showing pollution shrinks fetus size is particularly scary: http://www.news.qut.edu.au/cgi-bin/WebObjects/News.woa/wa/go...)
But I haven't seen experiments done with home air filters using health effects as the DV. I'd actually love to donate some filters to anyone in public health or medicine who wants to run that study!
Negative ionic air purifiers may help with SAD (seasonal depression) [1] similar to daylight bulbs. Research is somewhat inconclusive.
It also supposedly makes air have equivalent ionic levels to "country or mountain air". Apparently in the city/offices the ion levels in the air are quite lower than in rural areas which is harmful. This of course is the sales pitch from the companies selling them.
But at the same time the filters kill bacteria and pet dander (which is always good).
I found a HEPA air filter that contained negative ionizer for around ~$50 on Amazon which I use in my home office.
There is no "safe" threshold for particulate matter (PM) exposure. Our nose, mouth and throat are very inefficient at filtering particles less than 2.5 microns. As a consequence, a large proportion of these particles simply enter the respiratory tract (tracheobronchial and alveolar regions) relatively unimpeded.
Assessing indoor exposure to PM is challenging because it is highly dependent on location, the physical properties of the home, and human behaviour. Consequently, it can be difficult to clearly identify/quantify health benefits.
Even though you live in a reasonably clean city,
you can still further reduce your exposure to indoor PM by changing your behaviour, filtering your air and using existing equipment in your home properly.
1) In non-smoking homes, the biggest indoor source of PM is cooking (especially frying and broiling). You can reduce your exposure by a) keeping your range hood in good working order (change filters), b) using the range hood every time your cook, c) opening a window while cooking and d)stepping away from the stove whenever possible.
2) There are multiple other sources products that can produce shocking amounts of PM through direct emission and secondary reactions involving ozone. I would describe these exposures as completely unnecessary and can be eliminated by simply not using the products in the first place: a) candles, b) incense, and c)air fresheners and cleaning products with lemon & pine scents.
i don't have a study, but i live in santiago, which has smog in winter, and buying an air filter cured (or at least coincided with the cure of) my bronchitis.
