While carpets are comfortable and soft, most are made of synthetic fibers and can out-gas a lot of harmful chemicals. There are certainly better and worse options.
- For example, wool would be a relatively healthy choice.
- But, all carpets have the same problem in that they accumulate dust, so constant maintenance is necessary.
If you are not attached to installing a carpet, I would suggest considering a cork or rubber floor, which is relatively soft and probably much safer in terms of air quality.
For more information:
Read "I want low VOC carpet to replace my old carpeting. What are the best -- and least toxic -- conventional choices?" a Q&A answered by William Janhonen.