Table 2.
Heavy metal levels in the soil, drinking water, and air
a, Number of samples (number of samples above detection limit); b, Not applicable; c, Maximum level.
*, p<0.05 by Student's t-test.
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.