Table 3.

Qualitative classification of bottom sediments

Guidelines	Zn	Cd	Pb	Ni	Cu	Cr	Hg
Geochemical quality classesa (mg kg−1 d.m.)
Class I	125	0.7	30	16	20	50	0.2
Class II	300	3.5	100	40	100	100	0.7
Class III	1000	6	200	50	300	400	0.7
Class IV	>1000	>6	>200	>50	>300	>400	>0.7
Sediment quality guidelinesb (mg kg−1 d.m.)
TEC	121	0.99	35.8	22.7	31.6	43.3	0.18
PEC	459	4.98	128	48.6	149	111	1.06

^aBojakowska (2001)

²Macdonald et al. (2000)