Table 2 Concentrations of total mercury (THg, mg/kg) in Houttuynia cordata Thunb. (HCT) reported in the literature.

Danzhai, Guizhou

Zhijin, Guizhou

0.127 ± 0.061

0.039 ± 0.020

0.246 ± 0.115

0.036 ± 0.007

This study

Kiayang Guizhou

0.081 ± 0.121

–

Our previous study Wang et al.¹²

Farmlands, Sichuan and Chongqing

0.02–0.03

0.03–0.05

Chen et al.⁵²

Wanshan mercury mining area, Guizhou

1.5 ± 0.81

1.8 ± 0.72

Qian et al.¹⁷

A coal mining area, China

0.009

0.003

Li et al.⁵³