Assessment of Ecological Risk of Heavy Metals Using Probabilistic Risk Assessment Model (AQUARISK) in Surface Sediments from Wami Estuary, Tanzania

Table 6

AQUARISK estimates of species (%) likely to be affected by metals in sediment of Wami and the reductions required and median target concentrations required to achieve up to 5,10, or 25% species impact due to individual metal (95% confidence level).

Element	% of species affected			Required reduction (%)			Median target concentration (ngg^-1)
	HC5	HC10	HC25	HC5	HC10	HC25	HC5	HC10	HC25
As	3.4	3.4	3.4	NIL	NIL	NIL	1618.7	3066.4	8918.4
Cd	79.4	79.4	79.4	99.8	99.4	97.4	0.8	2.0	8.8
Cr	79.8	79.8	79.8	99.9	99.7	99.2	15.1	48.9	346.7
Cu	99.9	99.9	99.9	99.9	99.9	99.8	2.6	5.6	19.4
Pb	98.4	98.4	98.4	99.8	99.6	98.8	46.2	82.9	220.1
Zn	98.0	98.0	98.0	99.9	99.8	98.5	15.0	35.0	143.2