Indoor Air Environments

Indoor air qualityIndoor environments have opportunities to use Compression Thinking. Indoors is where we live, where the EPA estimates that we spend 90% of our time  – not counting time in vehicles. Inside most buildings, air is more polluted than outside.Hazards are serious enough that the EPA has an Indoor Environments Division. A host of associations, companies, and government agencies address indoor air quality in some way. All the rest of an indoor environment influences air quality. To get ideas, bone up well beyond this short piece, and think imaginatively and holistically.

If you’ve lived in a cabin burning wood, coal, or dung in an open fire, polluting crud is in your face. In developing regions, this contributes to 1-2 million deaths per year. Could air pollution in modern new buildings be less visible, but just as bad? Like 50,000 American deaths per year (sometimes claimed)? If so, why?
To put this in perspective, global deaths from all causes are about 58 million per year. About 400,000 perish from AIDS, over a million in traffic accidents, and 200,000 in fires. But chains of causality are hard to trace. Bad environments attack health in multiple ways over time, so mortality statistics based on final cause of death don’t reveal the stories leading up to them.

One reason air in newer buildings is polluted is that they are tightly built to reduce energy losses. If windows are never opened, air has to be circulated and filtered, which takes energy, but does not clean out everything. The list of known pollutants is long: Volatiles, molds, dust mites, animal and human dander, bacteria, viruses, etc., plus a lot of unknowns.

Competent cleaning, maintenance, and filtration will only diminish pollutants. Industrial clean room technology is beyond offices and domiciles. “Zero particulates” is impossible, so strive for a healthy indoor environment using very little to get it.

Much is unknown. For example, a hypothesis is that an environment can be too clean; living in one weakens immunity to attack when exposed to a dirtier one. And it was recently discovered that “secondary organic aerosols” persist in the air much longer than was thought. This is bad news, but whether we should tighten indoor and outdoor air standards is indeterminate. Sensors keep detecting particles not seen before. How they affect health is untested. To get novel ideas, follow a moving science, but bear in mind that one substance may present multiple hazards.

For example, volatiles in building materials and polymer-based furnishings both pollute indoor air and increase fire risks. A smoldering fire takes off quicker with most synthetics. Underwriters Laboratories recently tested the difference between a room furnished as in 1975 with a room more typical of today’s synthetic materials. Both were lit off with a candle in a sofa. The 1975 mock up flashed over in 29.5 minutes; the modern mock up flashed over in 3.5 minutes. The decrease in exit time is why they urge us to hang more and more smoke detectors everywhere.

None of us can anticipate this many interacting effects in depth without having a system for it. We assume that companies selling products do. However, few companies can do more than test one item at a time. No one can foresee the effects of a total living environment without addressing whole systems rather than pieces of them. But that’s where the opportunities are.

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