We cannot recommend specific indoor air quality (IAQ) consultants or testing companies. You can find some guidance for selecting companies providing IAQ services at web sites listed below.
IAQ services are expensive, particularly for home owners, and we recommend that you first become informed about IAQ issues and possible remedial measures. This IAQScience website provides much useful information to help you learn about IAQ problems and solutions. Web based information from the US Environmental Protection Agency is another excellent source. Many states also have indoor air quality information on the web sites of their Health Departments or Environmental Agencies. A website of the California Air Resources Board provides much helpful information.