re: Think

Smog is the result of Volatile Organic Compounds with a lot of particulate – think tiny grains of dust and soot mixed with  the invisible gases of carbon dioxide, nitrous oxide, formaldehyde, sulphur, and many others. Standard air conditioners have filters on the intake that keep particulate out – but the invisible stuff can still pass through.

Generally this is a problem only if your air intake is near a busy road, in the parking garage, or near the loading dock. For the rest of us, the invisible stuff
accumulates from the inside of our homes – from the things that we bring inside like:

cabinetry / flat pack furniture

insulation, lumber, and other
building materials

fire retardants in the building, electronics, upholstery, and clothing

paint, carpet, sealants, and adhesives

electronics, especially some laser printers

we spend up to 90% of our time indoors, where allergens, pollutants, and VOCs can build up - often resulting in worse air quality than outside, and contributing to the rise in childhood asthma

re: Start simple steps to take today

Use HEPA air filters and ionic air cleaners

Be suspicious of glues and finish coating

Look for “Low VOC” or “No VOC” on paints and other coatings. Green Seal, Green Guard, Cal 1350, and other labels are also clues that the product meets strict voluntary standards for low VOCs.

use natural fiber area rugs pollutants most wall to wall carpet will off-gas for it's whole life

Go shoeless or provide a walk-off mat: 90% of indoor pollutants are tracked in on the bottom of shoes.Eight feet of walk-off mat is recommended to fully clean shoes as they walk across the surface.

re: Generate dig a little deeper

Establish a strategy to replace or encapsulate MDF and other high VOC emitters in your environment. MDF will continue to off-gas for the life of the product, though the actual amount will reduce over time. For newer items, look for ways to completely seal up any exposed MDF this may require additional glue and materials, but tests have shown that it is an effective way to trap the gases where they wont harm you or other breathing creatures

Vow to not bring any more indoors! To reduce or eliminate the invisibles, look for durable goods made only with non-synthetic materials like solid wood, sea grass, leather, metal (avoid chromed finishes)

Check your printers, computers, and other larger electronics on the EPA website to determine which, if any, could be replaced with a less polluting version

Green plants: there are conflicting reports as to the effectiveness of plants in cleaning indoor air. If no one has allergies or other sensitivities, indoor plants can be beneficial on many levels

Use natural cleaning products

Reduce / eliminate products with fragrance on the ingredient label. This generic term can hide a multitude of irritating and toxic chemicals

Choose low- or zero-VOC paint for interior projects. Look for the Greenguard label for low-VOC formulations... unfortunately, this measure does not take into account the colorants (which may contain their own VOCs). Benjamin Moore's Natura is truly zero-VOC

Open the windows often fresh air dilutes build up

Remove the source of odors instead of covering up with air fresheners (those open windows come in handy here as well)

Be cautious of conventional upholstery and cushions, and even some clothing; all can be made of petroleum-based synthetics and may be treated with stain resistors, antimicrobials / pesticides, and/or fire retardants. Look for materials that are inherently flame resistant and long wearing, like wool, mohair, natural latex or down (for cushions).

Stain resistors may be surface applied (Scotchgard) or chemically bonded to the fibers (GoreTex or Crypton) but all are molecularly similar to Teflon. Of special concern is nanotechnology, which is responsible for NanoTex - also a PFTE (polytetrafluoroethylene; see below for more). All these treatments will wear off onto your skin and into your environment,
and at least one component is a known carcinogen.

Antimicrobials are pesticides according to the EPA; if you really need this attribute, look for fabric with embedded silver or copper (such as Agion or Cupron branded fibers) - these metals are inherently antimicrobial and will not wear off or off-gas

Fire retardants are often required by law, so it may be difficult to find mattresses and furniture cushions that do not contain brominated fire retardants (also called PBBs and PBDEs; PCBs, the chlorinated version, were banned in the US in the '70s). Unfortunately there are few chemicals currently known that are without the "side effects" of being persistent (not breaking down in the environment), bioaccumulative (moving up the food chain, where these chemicals have been found in alarming amounts in women's breast milk), disruptive to hormone systems (all mammals), and disruptive to reproductive systems (again, including people). For a very thorough discussion of all the issues around fire retardants, see Environmental Building News "Flame Retardants Under Fire" (click here for an action checklist). Invest in an organic mattress cover (to encase the chemicals and reduce your exposure) until you are able to replace it completely with a chemical-free product.

Nanotechnology shows great promise in medicine, where it makes many medications more effective byalowing them to bypass the body's natural defenses. But imagine by-passing those defenses with chemicals known to be carcinogenic. Neither the FDA nor the EPA currently require any special labeling or testing of nano-ingredients found in consumer products. (Another thorough review of this topic by Environmental Building News).

re: Imagine now you're talkin' Sustainable

Prefer durable goods made of natural materials, and avoid plastic whenever possible

Quit smoking

Have your chimney professionally cleaned and install filters on other air exhausts to make sure what you are emitting is as clean as possible, and is legal in your area (many regions are banning wood burning due to pollution concerns)

When it comes time to replace flooring at your home or office, consider hardwoods or bamboo (look for the
FSC label to ensure it was sustainably harvested), linoleum (made from agricultural products - renewable resources;
I like Forbo brand), carpet tile (look for the CRI Green Label to ensure low VOCs - I recommend InterfaceFlor
residential or commercial), or cork (also a natural, renewable product). Be aware of polyurethane finishes on linoleum and cork: this is a chemical wear layer which may or may not be necessary for your needs.

Make your own non-toxic cleaners. I recommend Annie Berthold-Bond's Better Basics for the Home.
This book also has recipes for all sorts of home projects, including engine de-greasers, milk paint, furniture sealant, etc.

Improve the insulation in your home to reduce the need for wall to wall carpeting. These measures in concert with an attic fan or other whole-house ventilation system will help your house "breathe" properly while improving your heating and cooling costs.