It is particularly important to contact your city, county, or state health department if you suspect that you have a serious building-related illness, such as multiple cases of building-related asthma or infectious diseases.

Even if available government agencies do not have the manpower or skills to assist in solving your IAQ problem they may be able to direct you to reputable firms in your area with the necessary experience.  Note that even certified professionals from disciplines closely related to IAQ (such as industrial hygienists, ventilation engineers, and toxicologists) may not have the specific expertise needed to investigate and resolve your problems.  Individuals or groups that offer services in this evolving field should be questioned closely about their related experience and their proposed approach to your concerns.