NPR's Tavis Smiley talks to health commentator Dr. Ian Smith about whether genetic and environmental factors play key roles in why people suffer from asthma.
Copyright 2004 NPR
NHPR is nonprofit and independent. We rely on readers like you to support the local, national, and international coverage on this website. Your support makes this news available to everyone.
Give today. A monthly donation of $5 makes a real difference.