Epidemiologic studies of miners have established a causal association
between radon exposure and development of lung cancer. During the past
decade the focus of attention has turned to the potential risk from e
xposure to radon in indoor air. Governmental involvement thus far has
primarily been aimed at gathering further data and issuing voluntary g
uidelines for radon control in the indoor environment. The federal gov
ernment's most recent risk assessment for exposure to indoor radon pub
lished in 1992 concluded that exposure to indoor radon results in 13,6
00 radon-induced lung cancer deaths in the United States each year. As
public awareness of such environmental issues continues to grow, phys
icians will be faced with the need to respond to inquiries regarding p
otential health effects. Man-made vitreous fibers are silicate glass t
hat have a noncrystalline structure. They have been in production for
more than 100 years and are used in numerous applications in residenti
al and commercial settings. The health risk from man-made vitreous fib
ers that are used in residential and commercial settings are limited t
o skin and occasional respiratory tract irritation under circumstances
of improper installation or maintenance. When glass fiber contaminate
s an indoor environment, proper repair measures and thorough cleaning
of the indoor environment will lead to resolution of any resultant irr
itant symptoms.