Very few of the materials we use in construction these days are single material products. Most are amalgams, held together with glues and binders, or made from petro chemicals. Unfortunately many of these chemicals leach out of the products over time, and can offgass and build up in the indoor environment. In some cases this can effect health, especially for those who are more chemically sensitive, and lead to what is known in the industry as 'Sick Building Syndrome'. When you come into a new house, or buy a new car, the offgassing of chemicals is at its maximum, which is why you get that "new car smell". But, rather than being a good thing, that new car smell could be making you sick.
Unfortunately the science in this area is in its infancy. Though regulators put limits on the amounts many chemicals are allowed to offgas, these are usually based on short term exposure testing. Very few studies look at chemical effects with long term exposure. Added to that, these chemicals are not often inert, meaning they may be reacting and forming new chemistry with each other. Even less is known about that.
We certainly don't want to fear monger, but instead suggest taking a precautionary approach when specifying materials. There are 2 things to look for. Firstly, for paints, glues, waterproof membranes and other liquids, choose products that are either 'low VOC' or 'zero VOC'. VOC stands for Volatile Organic Compound, and is a measure of how much a product offgasses.
For cabinetry, particleboard, medium density fibreboard (mdf), and other timber laminates, look for 'E0' rating, or 'Super E0'. E0 is a measurement of how much formaldehyde offgassing a product has. And the Australian legislated standard is E1, containing a higher level of VOC. Most of the board products use a urea formaldehyde glue to bind together the small bits of wood fibre. Unfortunately formaldehyde can offgass, and formaldehyde is a known human carninagen. So, again, it is worth just taking a precautionary approach and swap to lower offgassing materials where practical.
The main rule of thumb is to address the big surface areas. So choose a zero VOC paint, and low voc floorings. Then look at any non-solid timber in your house (usually in the cabinetry and trims). We have developed a long list of preferred products over the years, and there are more appearing in hardware stores all the time. It should no longer cost extra to have a healthy environment in your new house.
The good news for those who have just built without considering this, is that VOC's have usually returned to background levels after the first 12-24months. If however you are in that period, you might want to open the windows a bit...
(Note: Another good thing about passive solar designed homes, is that they are likely to heat up more in winter, so you will be able to open windows more often and earlier in the shoulder seasons, bringing in fresh air.)