Skip Navigation

Healthy Indoor Air

Americans spend a lot of time indoors: in our houses, at work and in school. It is just as important to care about the quality of our air while indoors as it is when we are outside.

According to the U.S Environmental Protection Agency (EPA), a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities. There is a wide variety of indoor air pollutants and an even larger variety of sources for these pollutants.


Image of a house with radon leaks.

Click to download (PDF, 200KB)


Suggestions for Improving Your Indoor Air

  • Properly ventilate your home. Increase the amount of fresh air by opening windows and doors or running air conditions and fans that exhaust to the outdoors.

  • Change heating and air conditioner filters regularly. Follow manufacturer recommendations. 

  • Adjust humidity. The EPA recommends a humidity level of between 30-50%. Too much humidity could potentially lead to mold.

  • Learn about potential indoor air pollutants and how to combat them. Click on the indoor air links below.

The EPA Publication "The Inside Story; A Guide to Indoor Air Quality" gives an overview of common indoor air quality problems and solutions.

EPA has a number of other publications related to indoor air quality on their Indoor Air Website.


Guides to Common Indoor Pollutants
 Asbestos ► Mold ► Radon ► CO2 ► Indoor Paint ► Lead


Finding an Indoor Air Quality Professional

In some cases, identifying and resolving an indoor air quality issue may require the services of an indoor air quality professional. These individuals and the companies that employ them have the necessary training, experience, and equipment to address a variety of indoor air quality concerns.

There are two principal categories of indoor air quality professionals:

  • Consultants diagnose and develop remediation plans for indoor air quality problems. Included in this category are industrial hygienists, indoor air quality specialists, asbestos and lead inspectors, and radon specialists.
  • Professionals perform the actual remediation services to address indoor air quality problems. Many firms provide both diagnostic and remediation services.

Image of vent Cleaning


Air Quality Certifications

There are several non-profit organizations that certify indoor air quality professionals. Although DEP cannot recommend the services of any particular individual or company, choosing a professional that has received the proper training and certification should help ensure you receive quality services. When selecting an indoor air quality professional, it is important to compare the services (and prices) of different professionals, check references, etc. just as you would for any other product or service.

Each of the organizations listed below has an on-line search feature that allows you to find professionals that provide the appropriate services in Montgomery County.