Journal of Waste Management

Research Article

Chromium Distribution and Spatial Variations in the Finer Sediment Grain Size Fraction and Unfractioned Surficial Sediments on Nyanza Gulf, of Lake Victoria (East Africa)

Table 2

Evaluation of sediment quality using the available threshold, mid-range, and extreme effect values (values given as % of samples exceeding the value for Cr).

(a) Threshold effect sediment quality guideline values (mg/kg)


	Unfractioned sediments ()	<63 µm grain size fraction ()

TEL (37.3)	20.7%	7.1%
ERL (80)	6.9%	0%
MET (55)	14%	3.6%
LEL (26)	51.7%	21.4%
CB-TEC (43.4)	17.2%	7.1%

(b) Mid-range effect sediment quality guideline values (mg/kg)


	Unfractioned sediments	<63 µm grain size fraction

PEL (90)	6.9%	0%
ERM (145)	0%	0%
EC (PEL) (160)	0%	0%

(c) Extreme effect sediment quality guideline values (mg/kg)


	Unfractioned sediments	<63 µm grain size fraction

TET (100)	0%	0%
SEL (110)	0%	0%
CB (PEC) (111)	0%	0%

TEL: threshold effect level; ERL/M: effects range low/medium; LEL: lowest effect level; CB: consensus based; MET: minimal effect level; SQAV: sediment quality advisory value (36 mg/kg threshold value); ISQG: interim sediment quality guideline (80 mg/kg threshold value); PEC: probable effect concentration; PEL: probable effect level; SEL: severe effect level; TET: toxic effect threshold; [57]: Australian and New Zealand Environment and Conservation Council (81 mg/kg threshold value); EC-TEL (52.3 mg/kg threshold value); NOAA-ERL (81 mg/kg threshold value); (a: [58]; b: [59]; c: [60]; d: [61]).