| Medium | Mercury (Hg) | Arsenic (As) |
| Soil | 0.0001 mg/g THg (US EPA, 2011 & Buchman, 2008) | 0.0004 mg/g (USEPA, 2011) |
| Plant | 0.0005 mg/g MeHg (FAO, 2013/WHO) | 0.0001 mg/g (FAO, 2013) |
| Sediment | 0.00018 mg/g THg (USEPA, 2006) | 0.0098 mg/g (USEPA, 2006) |
| Water | 0.006 mg/L Inorg. Hg (WHO, 2011) | 0.0010 mg/g (WHO, 2011) |
| Fish | 0.0003 mg/g MeHg (USEPA, 2011) | |
| 0.0005 mg/g MeHg (FAO, 2013) | ||
| Tailings | 0.0001 mg/g THg (US EPA, 2011 & Buchman, 2008) |