Table 6. Reference doses (RfD) in (mg/kg/day) and cancer slope factors (CSF) for the different heavy metals
| Elements | Classification by IARC1) | RfD (ug/g.d) | Source | CSF (ug/g.d)–1 | Source |
| Zn | | 3.00 × 10–1 | a/EPA | - | - |
| Mn | - | 1.40 × 10–1 | a/IRIS | - | - |
| Cu | | 4.00 × 10–2 | a | 1.70 × 10–1 | - |
| Cd | 1 | 1.00 × 10–3 | IRIS2) | 3.80 × 10–1 | CALEPA3)/USDOE, 2011 |
| Cr | 1 | 3.00 × 10–3 | 19,24 | 5.00 × 10–1 | CALEPA3)/19, 24 |
| Pb | 2B | 4.00 × 10–3 | WHO4) | 8.50 × 10–1 | CALEPA3) 37 |
| Ni | 1 | 2.00 × 10–2 | IRIS | 9.10 × 10–1 | CAFEPA3) |
International Agency for Research on cancer, group 1 chemicals and definite human carcinogens, group 2B, chemicals are possible human carcinogens, and group 3 chemicals are non–carcinogenic.
Integrated Risk Information System, US EPA.
Califronia Environmental Protection Agency, USA.
World Health Organization.