Metal content and distribution in surface sediments in
					an industrial region

SCHNEIDER, ISMAEL L.; TEIXEIRA, ELBA C.; RODRIGUES, MARIA LUCIA K.; ROLIM, SILVIA B.A.

doi:10.1590/0001-3765201420130137

ISMAEL L. SCHNEIDER

Programa de Pós-Graduação em Sensoriamento Remoto e Meteorologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre, RS, Brasil

ELBA C. TEIXEIRA

Programa de Pós-Graduação em Sensoriamento Remoto e Meteorologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre, RS, Brasil

Departamento de Pesquisa, Fundação Estadual de Proteção Ambiental Henrique Luis Roessler, Av. Borges de Medeiros, 261, 90020-023 Porto Alegre, RS, Brasil

MARIA LUCIA K. RODRIGUES

Fundação Estadual de Proteção Ambiental Henrique Luis Roessler, Rua Aurélio Porto, 37, 90620-090 Porto Alegre, RS, Brasil

SILVIA B.A. ROLIM

Programa de Pós-Graduação em Sensoriamento Remoto e Meteorologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre, RS, Brasil

Correspondence to: Ismael Luís Schneider E-mail: ismaelquimrs@yahoo.com.br

Figures (3)
Tables (8)

Thumbnail

Fig. 1
Study area with the sampling sites in the Sinos River basin.

Thumbnail

Fig. 2
Geochemical distribution of Ni, Zn, Cu, Cr, Pb, Mn, Al and Fe in the Sinos River basin sediments (Step 1 = available fraction, i.e., exchangeable and bound to carbonates; Step 2 = reducible fraction; Step 3 = oxidizable fraction; Step 4 = residual fraction).

Thumbnail

Fig. 3.
Correlation between the Zn concentration extracted from sediment samples with 0.5 mol/L HCl, and the sum of three labile phases extracted by sequential extraction procedure BCR (n = 10).

Thumbnail

TABLE I
Location of the sediment sampling sites.

Thumbnail

TABLE II
The BCR sequential extraction procedure.

Thumbnail

TABLE III
Additional parameters used for characterizing sediment samples from the Sinos River basin.

Thumbnail

Site Procedure analytical Cu mg/kg Zn mg/kg Ni mg/kg Cr mg/kg Pb mg/kg Al mg/g Fe mg/g Mn mg/g SI 188 Step 1 1.50 9.76 0.89 0.31 <2.0 0.19 0.28 0.55 Step 2 <0.60 13.2 0.98 1.32 8.24 2.19 6.57 0.13 Step 3 6.87 15.2 2.06 13.2 8.32 2.78 1.45 0.04 Step 4 60.9 94.1 35.2 106 10.6 91.2 77.6 0.34 0.5 M HCl - - - - - - - - Total 69.8 132 39.2 121 27.5 96.4 85.9 1.07 Rolante Step 1 0.87 4.55 1.11 0.39 <2.0 0.07 0.04 0.74 River Step 2 2.87 13.5 2.15 2.10 5.68 2.54 5.67 0.50 Step 3 4.71 10.9 2.91 13.3 5.74 2.32 0.99 0.09 Step 4 65.8 92.0 47.9 96.6 13.6 83.2 79.4 0.48 0.5 M HCl 16.2 13.8 2.37 1.84 7.02 - - - Total 74.2 121 54.1 112 25.4 88.1 86.1 1.81 SI 096 Step 1 0.77 1.17 0.73 0.18 <2.0 0.02 0.00 0.06 Step 2 4.59 2.77 1.38 1.84 5.22 1.73 3.02 0.36 Step 3 4.24 10.1 1.31 12.3 6.06 2.19 0.78 0.07 Step 4 59.6 97.6 38.1 101.6 16.0 92.9 77.4 0.66 0.5 M HCl 11.5 6.23 1.43 0.80 3.64 - - - Total 69.2 112 41.5 116 27.7 96.9 81.2 1.15 SI 066 Step 1 3.31 26.6 1.92 0.79 <2.0 0.07 0.19 1.02 Step 2 6.46 36.1 3.28 6.71 11.1 2.31 9.92 0.51 Step 3 7.29 12.5 3.73 25.2 4.16 1.90 1.10 0.05 Step 4 58.7 74.2 39.1 105 14.2 95.2 59.0 0.32 0.5 M HCl 29.1 48.4 3.74 5.95 11.3 - - - Total 75.8 149 48.0 138 29.9 99.4 70.2 1.90 Luiz Rau Step 1 25.1 120 8.23 1.14 <2.0 0.13 0.20 0.16 stream Step 2 28.8 66.6 7.98 10.6 19.4 1.60 4.75 0.05 Step 3 20.6 36.8 8.51 48.4 5.70 1.54 0.31 0.01 Step 4 46.6 66.3 10.2 68.1 34.0 113 47.2 0.18 0.5 M HCl 87.2 139.1 12.0 10.5 19.1 - - - Total 121 289.2 34.9 128 59.5 116 52.4 0.40 SI 048 Step 1 2.87 22.8 3.03 0.50 <2.0 0.03 0.01 0.44 Step 2 14.4 41.8 4.42 6.74 11.6 1.58 5.61 0.38 Step 3 9.88 22.6 3.79 43.6 8.04 1.69 0.85 0.08 Step 4 51.2 87.4 32.1 111 18.1 94.7 62.4 0.50 0.5 M HCl 32.9 48.8 5.68 5.16 11.6 - - - Total 78.3 175 43.4 162 38.1 98.0 68.9 1.39 Portão Step 1 1.62 66.5 11.0 5.91 <2.0 0.08 0.13 0.18 stream Step 2 7.63 61.6 13.4 87.9 16.5 2.20 7.95 0.10 Step 3 15.5 13.3 9.12 1038 9.48 2.51 1.54 0.02 Step 4 59.1 85.0 16.8 154 23.9 90.1 32.2 0.11

Site Procedure analytical Cu mg/kg Zn mg/kg Ni mg/kg Cr mg/kg Pb mg/kg Al mg/g Fe mg/g Mn mg/g 0.5 M HCl 45.6 91.9 20.9 117 18.9 - - - Total 83.9 226 50.3 1286 50.3 94.9 41.8 0.41 SI 036 Step 1 6.64 57.8 4.95 1.34 <2.0 0.05 0.32 0.53 Step 2 9.79 62.0 6.92 18.4 11.6 1.74 9.98 0.31 Step 3 16.2 20.7 4.81 76.2 5.43 1.77 1.24 0.05 Step 4 51.1 78.8 23.6 108 19.6 96.8 52.2 0.17 0.5 M HCl 45.1 92.8 9.41 18.6 12.7 - - - Total 83.7 219 40.2 204 37.1 100 63.8 1.07 SI 028 Step 1 8.49 52.4 5.15 1.07 <2.0 0.05 0.29 0.57 Step 2 11.4 59.6 6.78 14.7 10.9 1.79 10.6 0.33 Step 3 20.8 23.3 5.06 59.0 6.20 1.98 1.57 0.06 Step 4 55.5 79.0 30.5 108 18.4 96.2 53.3 0.19 0.5 M HCl 53.8 88.3 10.2 15.7 12.5 - - - Total 96.1 214 47.5 183 35.9 100 65.8 1.15 SI 019 Step 1 7.51 108 6.65 1.06 <2.0 0.07 0.55 0.32 Step 2 9.10 95.2 8.34 14.2 13.8 1.86 10.7 0.31 Step 3 29.1 29.4 5.76 64.2 7.46 2.01 2.34 0.06 Step 4 55.2 83.4 22.8 97.8 16.6 92.7 48.9 0.14 0.5 M HCl 59.5 154 11.9 16.1 15.6 - - - Total 101 316 43.5 177 38.2 96.7 62.4 0.82 SI 008 Step 1 11.9 124 7.83 1.10 <2.0 0.09 0.68 0.28 Step 2 15.8 93.7 9.40 16.8 14.7 2.31 11.0 0.26 Step 3 27.3 29.0 5.90 54.5 4.06 1.90 2.07 0.06 Step 4 54.4 67.0 17.9 96.0 17.7 90.4 46.7 0.14 0.5 M HCl 73.4 156 13.0 15.8 14.6 - - - Total 109 314 41.0 168 36.8 94.7 60.4 0.73

Thumbnail

TABLE V
Pearson correlation coefficient for metals in the sediments along the Sinos River and tributaries.

Thumbnail

TABLE VI
Best-fit regression models correlating concentrations of metals from sediments and extracted by 0.5 mol/L HCl, as well as the sum of the three labile phases extracted by sequential extraction procedure BCR (n = 10).

Thumbnail

TABLE VII
Metals concentration (mg/kg) in the study area (minimum-maximum) (average) compared with values from the literature.

Thumbnail

TABLE VIII
Comparison of average metal concentrations (mg/kg) in sediments of three stretches of the Sinos River basin with sediment quality guidelines (SQGs).

Site	Coordinates		Stretch of river
Site	X	Y	Stretch of river
SI 188	-50.263	-29.725	Upper
Rolante river	-50.470	-29.581	Upper
SI 096	-50.850	-29.686	Middle
SI 066	-51.046	-29.691	Lower
Luiz Rau stream	-51.126	-29.734	Lower
SI 048	-51.126	-29.737	Lower
Portão stream	-51.195	-29.778	Lower
SI 036	-51.194	-29.779	Lower
SI 028	-51.191	-29.796	Lower
SI 019	-51.188	-29.838	Lower
SI 008	-51.238	-29.875	Lower

STEPS	REAGENTS	PROCEDURE	SEDIMENT PHASES
1	Acetic acid 0.11 mol/L	1 g of sample + 40 mL of CH₃COOH stirred for 16 h at 30 rpm	Exchangeable – water soluble species and acid
2	0.10 mol/L hydroxylamine hydrochloride, pH 1.5	Residue of step 1 + 40 mL of NH₂OH. HCl stirred for 16 h at 30 rpm	Reducible – species bound to Fe and Mn oxides and hydroxides
3	1.0 mol/L ammonium acetate, after digestion with 8.8 mol/L hydrogen peroxide at pH 2	Residue of step 2 + 20 mL of H₂O₂ at 85°C almost until dry; 50 mL CH₃COONH₄ stirred for 16 h at 30 rpm	Oxidizable – species bound to organic matter and sulfides
4^* * Adopted herein.	Total concentration minus the sum of the previous three steps		Residual – species bound to the silicate matrix

Site	Particle size fraction (%)				Particle size classification	S (mg/kg)	OM (%)	Clay minerals
Site	gravel	sand	silt	clay	Particle size classification	S (mg/kg)	OM (%)	Clay minerals
SI 188	75.0	16.2	7.7	1.0	gravel and sand	764	16.8	smectite, illite, quartz, zeolite
Rolante river	12.8	84.6	1.9	0.8	sand	394	10.6	kaolinite, smectite, illite, k-feldspar, quartz
SI 096	0.0	48.8	34.5	16.7	mud with sand	224	8.7	kaolinite, smectite, k-feldspar, quartz
SI 066	0.0	46.0	41.6	12.4	mud with sand	511	12.1	kaolinite, smectite, k-feldspar, quartz
Luiz Rau stream	0.0	75.8	15.3	8.9	sand	267	11.1	kaolinite, smectite, illite, quartz
SI 048	0.0	71.3	19.5	9.2	sand with mud	286	10.0	kaolinite, smectite, k-feldspar, quartz
Portão stream	0.0	98.3	0.6	1.1	sand	922	15.8	barite, kaolinite smectite, quartz
SI 036	0.0	92.7	4.6	2.7	sand	637	9.8	kaolinite, smectite, illite, k-feldspar, quartz
SI 028	0.0	18.0	61.7	20.3	mud	729	11.5	kaolinite, smectite, quartz
SI 019	0.0	66.1	25.4	8.5	sand with mud	1301	12.0	kaolinite, smectite, k-feldspar, quartz
SI 008	0.0	52.2	37.4	10.3	sand with mud	1205	11.5	kaolinite, smectite, illite, quartz

Site	Procedure analytical	Cu mg/kg	Zn mg/kg	Ni mg/kg	Cr mg/kg	Pb mg/kg	Al mg/g	Fe mg/g	Mn mg/g
SI 188	Step 1	1.50	9.76	0.89	0.31	<2.0	0.19	0.28	0.55
	Step 2	<0.60	13.2	0.98	1.32	8.24	2.19	6.57	0.13
	Step 3	6.87	15.2	2.06	13.2	8.32	2.78	1.45	0.04
	Step 4	60.9	94.1	35.2	106	10.6	91.2	77.6	0.34
	0.5 M HCl	-	-	-	-	-	-	-	-
	Total	69.8	132	39.2	121	27.5	96.4	85.9	1.07
Rolante	Step 1	0.87	4.55	1.11	0.39	<2.0	0.07	0.04	0.74
River	Step 2	2.87	13.5	2.15	2.10	5.68	2.54	5.67	0.50
	Step 3	4.71	10.9	2.91	13.3	5.74	2.32	0.99	0.09
	Step 4	65.8	92.0	47.9	96.6	13.6	83.2	79.4	0.48
	0.5 M HCl	16.2	13.8	2.37	1.84	7.02	-	-	-
	Total	74.2	121	54.1	112	25.4	88.1	86.1	1.81
SI 096	Step 1	0.77	1.17	0.73	0.18	<2.0	0.02	0.00	0.06
	Step 2	4.59	2.77	1.38	1.84	5.22	1.73	3.02	0.36
	Step 3	4.24	10.1	1.31	12.3	6.06	2.19	0.78	0.07
	Step 4	59.6	97.6	38.1	101.6	16.0	92.9	77.4	0.66
	0.5 M HCl	11.5	6.23	1.43	0.80	3.64	-	-	-
	Total	69.2	112	41.5	116	27.7	96.9	81.2	1.15
SI 066	Step 1	3.31	26.6	1.92	0.79	<2.0	0.07	0.19	1.02
	Step 2	6.46	36.1	3.28	6.71	11.1	2.31	9.92	0.51
	Step 3	7.29	12.5	3.73	25.2	4.16	1.90	1.10	0.05
	Step 4	58.7	74.2	39.1	105	14.2	95.2	59.0	0.32
	0.5 M HCl	29.1	48.4	3.74	5.95	11.3	-	-	-
	Total	75.8	149	48.0	138	29.9	99.4	70.2	1.90
Luiz Rau	Step 1	25.1	120	8.23	1.14	<2.0	0.13	0.20	0.16
stream	Step 2	28.8	66.6	7.98	10.6	19.4	1.60	4.75	0.05
	Step 3	20.6	36.8	8.51	48.4	5.70	1.54	0.31	0.01
	Step 4	46.6	66.3	10.2	68.1	34.0	113	47.2	0.18
	0.5 M HCl	87.2	139.1	12.0	10.5	19.1	-	-	-
	Total	121	289.2	34.9	128	59.5	116	52.4	0.40
SI 048	Step 1	2.87	22.8	3.03	0.50	<2.0	0.03	0.01	0.44
	Step 2	14.4	41.8	4.42	6.74	11.6	1.58	5.61	0.38
	Step 3	9.88	22.6	3.79	43.6	8.04	1.69	0.85	0.08
	Step 4	51.2	87.4	32.1	111	18.1	94.7	62.4	0.50
	0.5 M HCl	32.9	48.8	5.68	5.16	11.6	-	-	-
	Total	78.3	175	43.4	162	38.1	98.0	68.9	1.39
Portão	Step 1	1.62	66.5	11.0	5.91	<2.0	0.08	0.13	0.18
stream	Step 2	7.63	61.6	13.4	87.9	16.5	2.20	7.95	0.10
	Step 3	15.5	13.3	9.12	1038	9.48	2.51	1.54	0.02
	Step 4	59.1	85.0	16.8	154	23.9	90.1	32.2	0.11

Site	Procedure analytical	Cu mg/kg	Zn mg/kg	Ni mg/kg	Cr mg/kg	Pb mg/kg	Al mg/g	Fe mg/g	Mn mg/g
	0.5 M HCl	45.6	91.9	20.9	117	18.9	-	-	-
	Total	83.9	226	50.3	1286	50.3	94.9	41.8	0.41
SI 036	Step 1	6.64	57.8	4.95	1.34	<2.0	0.05	0.32	0.53
	Step 2	9.79	62.0	6.92	18.4	11.6	1.74	9.98	0.31
	Step 3	16.2	20.7	4.81	76.2	5.43	1.77	1.24	0.05
	Step 4	51.1	78.8	23.6	108	19.6	96.8	52.2	0.17
	0.5 M HCl	45.1	92.8	9.41	18.6	12.7	-	-	-
	Total	83.7	219	40.2	204	37.1	100	63.8	1.07
SI 028	Step 1	8.49	52.4	5.15	1.07	<2.0	0.05	0.29	0.57
	Step 2	11.4	59.6	6.78	14.7	10.9	1.79	10.6	0.33
	Step 3	20.8	23.3	5.06	59.0	6.20	1.98	1.57	0.06
	Step 4	55.5	79.0	30.5	108	18.4	96.2	53.3	0.19
	0.5 M HCl	53.8	88.3	10.2	15.7	12.5	-	-	-
	Total	96.1	214	47.5	183	35.9	100	65.8	1.15
SI 019	Step 1	7.51	108	6.65	1.06	<2.0	0.07	0.55	0.32
	Step 2	9.10	95.2	8.34	14.2	13.8	1.86	10.7	0.31
	Step 3	29.1	29.4	5.76	64.2	7.46	2.01	2.34	0.06
	Step 4	55.2	83.4	22.8	97.8	16.6	92.7	48.9	0.14
	0.5 M HCl	59.5	154	11.9	16.1	15.6	-	-	-
	Total	101	316	43.5	177	38.2	96.7	62.4	0.82
SI 008	Step 1	11.9	124	7.83	1.10	<2.0	0.09	0.68	0.28
	Step 2	15.8	93.7	9.40	16.8	14.7	2.31	11.0	0.26
	Step 3	27.3	29.0	5.90	54.5	4.06	1.90	2.07	0.06
	Step 4	54.4	67.0	17.9	96.0	17.7	90.4	46.7	0.14
	0.5 M HCl	73.4	156	13.0	15.8	14.6	-	-	-
	Total	109	314	41.0	168	36.8	94.7	60.4	0.73

	Cr	Cu	Ni	Pb	Zn	Al	Fe	Mn	S	MO
Cr	1.000
Cu	0.040	1.000
Ni	0.370	0.421	1.000
Pb	0.450	0.727^* * Correlation is significant at the 0.05 level.	0.356	1.000
Zn	0.139	0.903^ Correlation is significant at the 0.01 level.	0.357	0.670^* * Correlation is significant at the 0.05 level.	1.000
Al	0.161	0.604^* * Correlation is significant at the 0.05 level.	0.687	0.710^* * Correlation is significant at the 0.05 level.	0.385	1.000
Fe	0.655^* * Correlation is significant at the 0.05 level.	0.644^* * Correlation is significant at the 0.05 level.	0.107	0.874^ Correlation is significant at the 0.01 level.	0.737^ Correlation is significant at the 0.01 level.	0.431	1.000
Mn	0.473	0.643^* * Correlation is significant at the 0.05 level.	0.505	0.777^ Correlation is significant at the 0.01 level.	0.700^* * Correlation is significant at the 0.05 level.	0.442	0.719^* * Correlation is significant at the 0.05 level.	1.000
S	0.280	0.346	0.059	0.054	0.638^* * Correlation is significant at the 0.05 level.	0.310	0.354	0.398	1.000
MO	0.555	0.098	0.058	0.126	0.053	0.144	0.197	0.357	0.492	1.000

Metal	Linear regression	r²
Cu	Σ₁₊₂₊₃ = 0.8483(HCl) − 5.0143	0.9587
Zn	Σ₁₊₂₊₃ = 1.5166(HCl) + 5.3756	0.9961
Ni	Σ₁₊₂₊₃ = 1.5554(HCl) + 2.4542	0.9762
Cr	Σ₁₊₂₊₃ = 0.2278(HCl) − 2.4881	0.9378
Pb	Σ₁₊₂₊₃ = 0.9854(HCl) + 6.1679	0.9049

Location	Cr	Cu	Ni	Zn	Pb	Mn	Reference
Sinos River	112 – 1,286	69.2 – 121	34.9 – 54.1	112 – 316	25.4 – 59.5	397 – 1,901	This study
Sinos River	254	87.5	44.0	206	37.0	1,081	This study
Lower part of the Sinos basin	20.0 – 1,200	20.0 – 1,175	20.0 – 325	50.0 – 5,300	20.0 – 200	^* * Not available.	Robaina et al. 2002Robaina LE, Formoso MLL and Pires CAF. 2002. Metais pesados nos sedimentos de corrente, como indicadores de risco ambiental – Vale do rio dos Sinos, RS. Rev I Geol 23: 35-47. Rodrigues MLK and Formoso MLL. 2006. Geochemical distribution of selected heavy metals in stream sediments affected by tannery activities. Water Air Soil Poll 169: 167-184.
Soil at two landfills near the Sinos river	205 – 1,744	35.0 – 94.0	13.0 – 44.0	57.0 – 355	23.0 – 70.0	200 – 900	Oliveira et al. 2008Oliveira MTG, Rolim SBA, Mello-Farias PC, Meneguzzi A and Lutckmeier C. 2008. Industrial pollution of environmental compartments in the Sinos River Valley, RS, Brazil: geochemical–biogeochemical characterization and remote sensing. Water Air Soil Poll 192: 183-198.
Cadeia River - Brazil	34.7 – 423	57.8 – 102	27.0 – 74.9	122 – 147	^* * Not available.	1,090 – 2,210	Rodrigues and Formoso 2006
Feitoria River - Brazil	169 – 1,031	93.8 – 106	71.2 – 91.1	136 – 145	^* * Not available.	1,080 – 2,230	Rodrigues and Formoso 2006
Estrela River - Brazil	8.44 – 100	10.0 – 74.5	26.0 – 95.9	42.5 – 351	45.8 – 121.4	164 – 811	Rangel et al. 2011Rangel CMA, Baptista Neto JA, Fonseca EM, McAlister J and Smith BJ. 2011. Study of heavy metal concentration and partitioning in the Estrela River: implications for the pollution in Guanabara Bay – SE Brazil. An Acad Bras Cienc 83: 801-815.
Sakarya river - Turkey	37.0	37.5	83.0	76.7	41.3	772	Dundar et al. 2012Dundar MS, Altundag H, Eyupoglu V, Keskin SC and Tutunoglu C. 2012. Determination of heavy metals in lower Sakarya River sediments using a BCR-sequential extraction procedure. Environ Monit Assess 184: 33-41.
Seyhan River - Turkey	46.3 – 122	3.68 – 57.2	82.2 – 215	34.2 – 146	11.3 – 74.7	144 – 638	Davutluoglu et al. 2011Davutluoglu OI, Seckin G, Ersu CB, Yilmaz T and Sari B. 2011. Heavy metal content and distribution in surface sediments of the Seyhan River, Turkey. J Environ Manage 92: 2250-2259.
Rivers in the Jiangsu Province - Eastern China	345 – 9,671	440 – 9,797	251 – 2,846	391 – 1,483	17.2 – 106	338 – 782	Hang et al. 2009Hang X, Wang H, Zhou J, Du C and Chen X. 2009. Characteristics and accumulation of heavy metals in sediments originated from an electroplating plant. J Hazard Mater 163: 922-930.
Brunette River - Canada	^* * Not available.	12.0 – 225	^* * Not available.	56.0 – 335	63.0 – 722	217 – 1,452	Li et al. 2009Li LY, Hall K, Yuan Y, Mattu G, McCallum D and Chen M. 2009. Mobility and bioavailability of trace metals in the water-sediment system of the highly urbanized Brunette watershed. Water Air Soil Poll 197: 249-266.
Deûle-canal - Northern France	^* * Not available.	^* * Not available.	^* * Not available.	149 – 12,895	26.8 – 10,079	^* * Not available.	Boughriet et al. 2007Boughriet A, Proix N, Billon G, Recourt P and Ouddane B. 2007. Environmental impacts of heavy metal discharges from a smelter in Deûle-canal sediments (Northern France): concentration levels and chemical fractionation. Water Air Soil Poll 180: 83-95.
Oka River - Spain	20.0 – 180	30.0 – 150	30.0 – 130	100 – 360	30 – 110	370 – 1,600	Irabien and Velasco 1999Irabien MJ and Velasco F. 1999. Heavy metals in Oka River sediments (Urdaibai National Biosphere Reserve, northern Spain): lithogenic and anthropogenic effects. Environ Geol 37: 54-63.
Background	80.3	39.4	50.5	82.4	42.0	^* * Not available.	Robaina et al. 2002Robaina LE, Formoso MLL and Pires CAF. 2002. Metais pesados nos sedimentos de corrente, como indicadores de risco ambiental – Vale do rio dos Sinos, RS. Rev I Geol 23: 35-47. Rodrigues MLK and Formoso MLL. 2006. Geochemical distribution of selected heavy metals in stream sediments affected by tannery activities. Water Air Soil Poll 169: 167-184.
Average shale	90.0	45.0	68.0	95.0	20.0	850	Turekian and Wedepohl 1961Turekian KK and Wedepohl KH. 1961. Distribution of elements in some major units of the earth's crusts. Geol Soc Am Bull 72: 175-192.

Metal	Canadian Sediment Quality Guidelines^a a CCME (1999),		Sediment quality guidelines^b b Long et al. (1995),				Average by stretch of the Sinos River basin
Metal	ISQG	PEL	TEL	PEL	ERL	ERM	Upper	Middle	Lower
Cu (mg/kg)	35.7	197	18.7	108.2	43	270	72.0	69.2	93.6
Zn (mg/kg)	123	315	124	271	150	410	127	112	238
Ni (mg/kg)	^* * Not available.	^* * Not available.	15.9	42.8	20.9	51.6	46.6	41.5	43.6
Cr (mg/kg)	37.3	90.0	52.3	160.4	81.0	370	116	116	306
Pb (mg/kg)	35.0	91.3	30.2	112.2	46.7	218	26.5	27.7	40.7
Al (mg/g)	^* * Not available.	^* * Not available.	^* * Not available.	^* * Not available.	^* * Not available.	^* * Not available.	92.2	96.9	100
Fe (mg/g)	^* * Not available.	^* * Not available.	^* * Not available.	^* * Not available.	^* * Not available.	^* * Not available.	86.0	81.2	60.7
Mn (mg/g)	^* * Not available.	^* * Not available.	^* * Not available.	^* * Not available.	^* * Not available.	^* * Not available.	1.44	1.15	0.98

[1] Correspondence to: Ismael Luís Schneider E-mail: ismaelquimrs@yahoo.com.br

Brasil

Brasil

Metal content and distribution in surface sediments in an industrial region