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.
Geological map of the study area located in Upper Northern Thailand. (A) Geographical coordinates in Chiang Mai, Thailand. (B) Map of the study area. (C) Incidence of new lung cancer cases in the total of 25 districts of Chiang Mai from the years 2013 to 2015. (D) Frequency distribution of sampling sites in the study area.
