Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Log plot of lung cancer mortality rate versus age among never, former and continuing (current) smokers who started smoking at age 18–22 years. •, ▴, ▪ and ◆ denote ex‐smokers who quit at ages 40–49, 50–59, 60–69 and 70–79 years, respectively.
