As is commonly found in homes of this age, the supply air ducts have been fabricated from a cardboard material that often contains a*****estos fibers. The presence of a*****estos could not be verified, as laboratory testing is required.
A*****estos in general has been related to health and safety issues. While its use as insulation on heating system ductwork is common, this type of fabrication may allow the release of fibers into the home when the ductwork becomes damaged. Improvements to replace the ductwork may be desirable.
Further evaluation and testing by a specialist in the appropriate field is recommended.
