The U.S. Environmental Protection Agency (EPA) states: "Standards for airborne concentrations of mold, or mold spores, have not been set. Currently, there are no EPA regulations or standards for airborne mold contaminants."
Therefore, Washtenaw County does not recommend testing for mold. Although visible mold can be tested by an environmental consultant, these tests can be very expensive and are considered unnecessary by environmental health professionals. There is also no easy or inexpensive way to sample for airborne mold spores. Further, since mold occurs everywhere, all testing results will indicate the presence of mold. Finally, even if you were to have your home tested, it is difficult to say at what levels mold may cause health effects.
Preventative action is best. Whenever you can see mold or smell mold odors, simply assume there is a problem and take measures to reduce the presence of mold in your home.