Heavy Metal Contamination in Soil and Brown Rice and Human Health Risk Assessment near Three Mining Areas in Central China

Table 1

Reference doses () and slope factors () of five heavy metals.

Elements	Classification; by IARC^a	RfD (mg/(kg/day))	Source	SF; (mg/(kg/day)^−1)	Source
Cd	1	0.001	IRIS^b	15	CALEPA^c
As	1	0.003	IRIS	1.5	IRIS
Pb	2B	0.0036	WHO^d	—
Mn	—	0.14	IRIS	—
Sb	2B	0.004	IRIS	—

Note. ^aThe International Agency for Research on Cancer defines human carcinogens as class 1 and possible human carcinogens as class 2B. ^bIntegrated Risk Information System, USEPA. ^cCalifornia Environmental Protection Agency, US. ^dWorld Health Organization.