. 2020 Feb 12;17(4):1156. doi: 10.3390/ijerph17041156
© 2020 by the authors.
Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Figure 2.
Study area and spatial distribution of sample.