Table 2.

Heavy metal risk reference slope factors (SFs) and reference doses (RfDs; mg/(kg·d)).

Metal	RfDing	RfDderm	RfDinh	SFderm
Cu	4 × 10−2	4 × 10−2	1.2 × 10−2
Cr	3 × 10−3	2.86 × 10−5	6 × 10−5
Ni	2 × 10−2	2.06 × 10−2	5.4 × 10−3	8.4 × 10−1
Zn	0.3	0.3	0.06
Pb	3.5 × 10−3	3.52 × 10−3	5.25 × 10−3
Cd	1 × 10−3	1 × 10−3	5 × 10−5	6.4
As	3 × 10−4	3.01 × 10−4	1.23 × 10−4	1.5
Hg	3 × 10−4	8.57 × 10−5	2.1 × 10−5
Mn	4.6 × 10−2	1.43 × 10−5	1.84 × 10−3
Co	2 × 10−2	5.71 × 10−6	1.60 × 10−2	9.8