by Mike Fallarino, Contributing Editor
While the green community focuses on manufacturing methodology, the chemicals and raw materials that make up building products, and the seemingly endless avenues that comprise ways to save energy, there remains a largely hidden world that is a vital part of the indoor air quality equation. Chalk this view up to my background in complementary and alternative medicine, but our lungs are woefully under appreciated work horses of IAQ conditioning and purification.
In this March's issue of GBPD, I wrote about the vital role that optimal levels of relative humidity play in our structures, and why I think it's a good idea to accurately monitor indoor RH and condition it accordingly. This column looks at IAQ from another perspective: the ubiquitous world of dust.
Frankly, I've been freaked out about dust and particulate matter for the several years that I've inhabited my current digs. There was a large uptick in the sheer volume of dust that I've had to contend with as I migrated from my previous house to my current one. An increase that cannot be attributed to any change in personal functioning. Worrisome amounts of particulates settle on every surface in the house, vertical included. And the quantity that resettles on my laboriously dusted surfaces just a week after I've expended the effort to remove it is an ongoing cause for concern.
What is this damn stuff exactly, where does it come from, and how does it get here? I'm sure that the fact that I live in a leaky rental house next to a dog kennel, just 700 feet from a major state highway, and directly across from the county airport has something to do with the sheer volume of dust in my home.
Last night I watched the Hartmut Bitomsy film Dust (www.icarusfilms.com - 2007, Icarus Films). The film is in some ways an equivalent video analog to a book that made the Amazon editor's top picks of the year list a few years back, Hannah Holmes The Secret Life of Dust.
Dust is a German film with English subtitles. At 90 minutes it succinctly meanders through the multifarious pathways of dust generation, accumulation, examination, and elimination. For me, the strongest highlight in the film is one scientist's concise explanation of what particulates actually are and how they affect us:
“The particulate matter in our town is quite a mixture. There are very tiny particles we call ultra-small. They're tinier than 100 nanometers: you can't see them under a microscope; they're the same size as the molecules in our body. We now know that not all of these particles remain in the lungs; a small percentage enter the bloodstream. These ultra-small particles are emitted during combustion, and once in outdoor air, they grow into larger particles.
“So particulate matter in town includes larger particles which consist of groups of ultra-small particles mixed with gas-like substances which include oils, transition metals, and lots of heavy metals. So there is a range of between 100 nanometers and one micrometer – where we begin to see the larger particles which are stable and visible. They are relatively well-distributed in our cities and can be carried from 4,000 km (2,485 miles) away. When we inhale them, the lung's macrophages tend to recognize them as bacteria. The problem is that the particles are actually inorganic, so when the macrophages attack them, infectious reactions of the lung can result, sometimes leading to cardiac harm....”
This underpins a point that building science specialist Mark LaLiberte made in a recent article Clearing the Air, when he wrote that visible particulate matter in our structures accounts for less than 2 percent of the 500,000 to one million particles floating around in every cubic foot of air.
Wowie zowie! And I was worried about the dust I could actually see settling on my wooden buddha head! Man, I really need a life.
Add to all this the concept of the “personal cloud” which is covered in both Bitomsy's film and Holmes' book. The idea is that all of us move around with a somewhat nondescript cloud of particulate matter which is comprised of hundreds of thousands of our own skin flakes along with all a particulate-sized array of all the things we repeatedly come into contact with through our respective occupations.
So where does all this leave us? Well, if you're thinking active filtration you're on the right track. Portable and room-based air filtration units are probably better than nothing, but the best whole-house solutions will likely be found with up-to-date HVAC equipment that is designed to protect human health. There is a new market here for manufacturers, engineers, and contractors who deal with whole house IAQ.
As for me and my rental house, I guess there's a reason I intuitively painted the ceiling of my bedroom dusty rose.
Archived Content:
Collaborative Efforts • 9-10/2009
Archived Content:
The Case for Sill Pans
Archived Content:
The Greening of Home Electronics
Archived Content:
Air Washers
Archived Content:
Moisture Meters 2
Archived Content:
Panasonic's IAQ initiatives
