After reading this article, I may
have an answer for why a routine chest X ray indicated prominent scar tissue on my lungs
even though I have never been a smoker during my 61 years. For the past 15 years, since a
heart attack, I have jogged or ridden a bicycle for approximately an hour a day, 5 days a week,
in Southern California. From now on, I’ll confine my exercise to indoors.
From the Nature Index
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