The case is different completely when it was exposed in indoor, as raw rubber can be used in indoor exposure 5 years or more after.

For example, indoor radon exposure was estimated to cause between 3-14 % of all lung cancers in 2004, the second most important cause of lung cancer in many countries.

Certain immediate effects are similar to those from colds or other viral diseases, so it is often difficult to determine if the symptoms are a result of exposure to indoor air pollution.