No, but it’s common that they do. Gravity furnaces weren’t terribly efficient so wrapping either the ductwork in asbestos, the furnace itself, or both, was something done regularly. This allowed the system to retain more heat. At the time, this greatly enhanced the efficiency of the furnaces but it wasn’t until later that we became aware of just how carcinogenic and dangerous asbestos could be.

While a professional can always help, there are some common plumbing culprits you can check yourself to see if you can find the sewer gas smell. For example, you should check your water traps, sometimes called P-traps and S-traps, which are located under sink, shower, and laundry drains. The wax ring beneath the base of your toilet, which creates a watertight seal with the plumbing, could also have gone bad.

A professional indoor air quality inspection takes anywhere from one to three hours, depending on the size of your home and the number of necessary samples. After the test, the specialist will discuss the findings, but you won’t get a full written report for 2 to 10 days, though you can ask your pro to expedite the process, if needed. 

Mold, VOCs, radon, carbon monoxide, and particulate matter are typically measured.