The rate at which that carpet you specified off-gasses
Off-gassing (AKA outgassing) means any chemicals in a material or product can and will release those chemicals into the air (chemicals with a high rate of off-gassing are considered volatile organic compounds). It is an important part of maintaining healthy interior air quality (see description from LEED). Problems with interior air quality can sometimes warrant the use of the term ‘Sick Building Syndrome‘, indicating that being in a particular building can have an adverse affect on your health.
The good news about carpet is that it has gone out of style. The bad news is other flooring has their own off-gassing issues, along with more acoustical problems (carpet does do a good job absorbing impacts). With any material, building codes, local laws and green building standards have made it easier to check and reduce off-gassing issues.