Introduction
Materials and methods
Study area description
Sites | Stations | Latitude | Longitude | As | Hg | Pb | Cr | Ni |
---|---|---|---|---|---|---|---|---|
North | 1 | 4029710 | 727406 | 0.15 | ND | 0.83 | 0.415 | 1.22 |
2 | 4027701 | 728482 | 0.14 | ND | 0.415 | 0.565 | 0.9 | |
3 | 4025335 | 724454 | 0.12 | ND | 0.705 | 0.97 | 3.2 | |
4 | 4027198 | 721742 | 0.27 | ND | 1.065 | 6.03 | 1.225 | |
5 | 4025914 | 725243 | 0.15 | ND | 0.485 | 2.725 | 1.555 | |
6 | 4018132 | 735467 | 0.25 | ND | 0.705 | 3.65 | 1.885 | |
7 | 4018221 | 735984 | 0.20 | ND | 0.365 | 17.67 | 0.45 | |
South | 8 | 4017602 | 736047 | 0.17 | ND | 0.36 | 0.36 | 0.795 |
9 | 4014001 | 733598 | 0.09 | ND | 0.525 | 0.535 | 0.395 | |
10 | 4014963 | 733130 | 0.20 | ND | 0.485 | 3.825 | 1.09 | |
11 | 4016330 | 740638 | 0.21 | ND | 0.385 | 8.245 | 0.185 | |
12 | 4014951 | 743628 | 0.18 | ND | 0.31 | 8.265 | 1.27 | |
13 | 4023448 | 728776 | 0.14 | ND | 0.59 | 6.41 | 1.31 | |
14 | 4024096 | 731871 | 0.18 | ND | 0.395 | 10.21 | 0.36 | |
East | 15 | 4020529 | 737745 | 0.10 | ND | 0.33 | 0.68 | 0.28 |
16 | 4022731 | 739408 | 0.19 | ND | 0.515 | 11.17 | 0.23 | |
17 | 4023714 | 732412 | 0.12 | ND | 0.375 | 23.25 | 1.715 | |
18 | 4025587 | 735752 | 0.28 | ND | 0.625 | 0.47 | 1.815 | |
19 | 4025452 | 734910 | 0.21 | ND | 0.495 | 0.565 | 0.35 | |
20 | 402041 | 728081 | 0.15 | ND | 0.56 | 0.59 | 0.58 | |
21 | 4023401 | 721575 | 0.16 | ND | 0.75 | 4.16 | 0.86 | |
West | 22 | 4024240 | 723377 | 0.16 | 0.2 | 0.54 | 2.415 | 1.715 |
23 | 4021934 | 723688 | 0.39 | ND | 1.33 | 6.34 | 13.145 | |
24 | 4023475 | 726604 | 0.18 | ND | 0.31 | 7.51 | 0.4 | |
25 | 4021665 | 730176 | 0.18 | ND | 0.625 | 0.315 | 3.05 | |
26 | 4020791 | 733368 | 0.23 | ND | 0.53 | 1.185 | 2.96 | |
27 | 4019883 | 732363 | 0.24 | ND | 0.64 | 4.455 | 1.405 | |
28 | 4017836 | 732942 | 0.20 | ND | 0.745 | 5.56 | 2.47 | |
Center | 29 | 4016239 | 733048 | 0.23 | ND | 0.505 | 4.08 | 1.49 |
30 | 4019093 | 730563 | 0.20 | ND | 0.54 | 2.525 | 1.145 | |
31 | 4019123 | 734946 | 0.14 | ND | 0.56 | 1.59 | 1.515 | |
32 | 4017372 | 734784 | 0.16 | 0.2 | 0.575 | 7.875 | 0.95 | |
33 | 4019664 | 734467 | 0.13 | ND | 0.45 | 1.435 | 1.59 | |
34 | 4018134 | 734290 | 0.20 | 0.1 | 0.81 | 19.5 | 3.63 | |
35 | 4019632 | 735625 | 0.14 | ND | 0.635 | 0.4 | 1.19 | |
Mean | 0.18 | 0.01 | 0.58 | 4.94 | 1.69 | |||
Standard deviation | 0.05 | 0.048 | 0.206 | 5.53 | 2.15 | |||
*Asymp sig | 0.01 | < 0.001 | 0.02 | < 0.001 | 0.03 | |||
RfD via ingestion pathway (mg/kg/day) | 0.0003 | 0.0003 | 0.0035 | 0.003 | 0.02 | |||
RfD via dermal pathway (mg/kg/day) | 0.000285 | 0.0003 | 0.000525 | 0.000075 | 0.0003 |
Sampling, preservation, and transportation
Chemical analysis
Quality control and assurance
Health risk assessment
Problem formulation
Exposure assessment
Non-carcinogenic risks
Carcinogenic risks
Statistical analysis
Results and discussion
Heavy metal distribution
Heavy metals | As | Hg | Pb | Cr | Ni |
---|---|---|---|---|---|
In this study (n = 140) | |||||
North | 0.18 ± 0.058 | NA | 0.65 ± 0.25 | 4. 58 ± 6.11 | 1.49 ± 0.88 |
South | 0.17 ± 0.042 | NA | 0.65 ± 0.99 | 5.41 ± 3.91 | 0.77 ± 0.46 |
East | 0.17 ± 0.060 | NA | 0.52 ± 0.12 | 5.84 ± 8.61 | 0.83 ± 0.67 |
West | 0.23 ± 0.08 | 0.03 ± 0.08 | 0.67 ± 0.32 | 3.98 ± 2.72 | 3.59 ± 4.31 |
Center | 0.17 ± 0.045 | 0.04 ± 0.02 | 0.60 ± 0.12 | 4.91 ± 6.33 | 1.79 ± 0.915 |
Other cities | |||||
Ahvaz* [1] | 5.80 ± 1.63 | 2.8 ± 0.3 | 21.1 ± 4.4 | 5.3 ± 3.6 | – |
Tehran** [2] | 2.3 ± 0.76 | 0.52 ± 0.03 | 4.5 ± 0.49 | – | – |
Other countries | |||||
Australia [3] | 0.64 ± 0.1 | – | 5.21 ± 1.43 | 4.43 ± 1.21 | 7.93 ± 2.4 |
China [4] | – | 0.07 ± 0.25 | 5.06 ± 1.73 | 2.84 ± 0.76 | – |
1.06 ± 1.74 | 0.10 ± 0.13 | 16.7 ± 18.5 | 0.58 ± 0.52 | 6.13 ± 4.38 | |
India [7] | 32 ± 5.6 | 0.76 ± 0.32 | 46.2 ± 12.56 | 28.3 ± 4.9 | 34.6 ± 14.17 |
Malaysia [8] | 2.51 ± 0.65 | 0.11 ± 0.0.6 | 5.18 ± 1.04 | 2.19 ± 0.93 | 5.63 ± 1.67 |
Standards | |||||
WHO [9] | 10 | 6 | 10 | 50 | 70 |
EPA [6] | 10 | 2 | 15 | 100 | 20 |
Local standard in Irana [10] | 10 | 6 | 10 | 50 | 70 |
Health risk assessment
Average daily dose
Sites/stations (n = 140) | ADD of individuals heavy metals (μg kg−1 day−1) | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
As | Hg | Pb | Cr | Ni | |||||||
Adult | Child | Adult | Child | Adult | Child | Adult | Child | Adult | Child | ||
North | 1 | 0.005 | 0.017 | ND | ND | 0.030 | 0.093 | 0.015 | 0.047 | 0.044 | 0.137 |
2 | 0.005 | 0.016 | ND | ND | 0.015 | 0.047 | 0.020 | 0.064 | 0.032 | 0.101 | |
3 | 0.004 | 0.014 | ND | ND | 0.025 | 0.079 | 0.035 | 0.109 | 0.114 | 0.360 | |
4 | 0.010 | 0.030 | ND | ND | 0.038 | 0.120 | 0.215 | 0.678 | 0.044 | 0.138 | |
5 | 0.005 | 0.017 | ND | ND | 0.017 | 0.055 | 0.097 | 0.307 | 0.056 | 0.175 | |
6 | 0.009 | 0.028 | ND | ND | 0.025 | 0.079 | 0.130 | 0.411 | 0.067 | 0.212 | |
7 | 0.007 | 0.023 | ND | ND | 0.013 | 0.041 | 0.631 | 1.988 | 0.016 | 0.051 | |
South | 8 | 0.006 | 0.019 | ND | ND | 0.013 | 0.041 | 0.013 | 0.041 | 0.028 | 0.089 |
9 | 0.003 | 0.010 | ND | ND | 0.019 | 0.059 | 0.019 | 0.060 | 0.014 | 0.044 | |
10 | 0.007 | 0.023 | ND | ND | 0.017 | 0.055 | 0.137 | 0.430 | 0.039 | 0.123 | |
11 | 0.008 | 0.024 | ND | ND | 0.014 | 0.043 | 0.294 | 0.928 | 0.007 | 0.021 | |
12 | 0.006 | 0.020 | ND | ND | 0.011 | 0.035 | 0.295 | 0.930 | 0.045 | 0.143 | |
13 | 0.005 | 0.016 | ND | ND | 0.021 | 0.066 | 0.229 | 0.721 | 0.047 | 0.147 | |
14 | 0.006 | 0.020 | ND | ND | 0.014 | 0.044 | 0.365 | 1.149 | 0.013 | 0.041 | |
East | 15 | 0.004 | 0.011 | ND | ND | 0.012 | 0.037 | 0.024 | 0.077 | 0.010 | 0.032 |
16 | 0.007 | 0.021 | ND | ND | 0.018 | 0.058 | 0.399 | 1.257 | 0.008 | 0.026 | |
17 | 0.004 | 0.014 | ND | ND | 0.013 | 0.042 | 0.830 | 2.616 | 0.061 | 0.193 | |
18 | 0.010 | 0.032 | ND | ND | 0.022 | 0.070 | 0.017 | 0.053 | 0.065 | 0.204 | |
19 | 0.008 | 0.024 | ND | ND | 0.018 | 0.056 | 0.020 | 0.064 | 0.013 | 0.039 | |
20 | 0.005 | 0.017 | ND | ND | 0.020 | 0.063 | 0.021 | 0.066 | 0.021 | 0.065 | |
21 | 0.006 | 0.018 | ND | ND | 0.027 | 0.084 | 0.149 | 0.468 | 0.031 | 0.097 | |
West | 22 | 0.006 | 0.018 | 0.007 | 0.023 | 0.019 | 0.061 | 0.086 | 0.272 | 0.061 | 0.193 |
23 | 0.014 | 0.044 | ND | ND | 0.048 | 0.150 | 0.226 | 0.713 | 0.469 | 1.479 | |
24 | 0.006 | 0.020 | ND | ND | 0.011 | 0.035 | 0.268 | 0.845 | 0.014 | 0.045 | |
25 | 0.006 | 0.020 | ND | ND | 0.022 | 0.070 | 0.011 | 0.035 | 0.109 | 0.343 | |
26 | 0.008 | 0.026 | ND | ND | 0.019 | 0.060 | 0.042 | 0.133 | 0.106 | 0.333 | |
27 | 0.009 | 0.027 | ND | ND | 0.023 | 0.072 | 0.159 | 0.501 | 0.050 | 0.158 | |
28 | 0.007 | 0.023 | ND | ND | 0.027 | 0.084 | 0.199 | 0.626 | 0.088 | 0.278 | |
Center | 29 | 0.008 | 0.026 | ND | ND | 0.018 | 0.057 | 0.146 | 0.459 | 0.053 | 0.168 |
30 | 0.007 | 0.023 | ND | ND | 0.019 | 0.061 | 0.090 | 0.284 | 0.041 | 0.129 | |
31 | 0.005 | 0.016 | ND | ND | 0.020 | 0.063 | 0.057 | 0.179 | 0.054 | 0.170 | |
32 | 0.006 | 0.018 | 0.007 | 0.023 | 0.021 | 0.065 | 0.281 | 0.886 | 0.034 | 0.107 | |
33 | 0.005 | 0.015 | ND | ND | 0.016 | 0.051 | 0.051 | 0.161 | 0.057 | 0.179 | |
34 | 0.007 | 0.023 | 0.004 | 0.011 | 0.029 | 0.091 | 0.696 | 2.194 | 0.130 | 0.408 | |
35 | 0.005 | 0.016 | ND | ND | 0.023 | 0.071 | 0.014 | 0.045 | 0.043 | 0.134 | |
Mean | 0.007 | 0.021 | 0.001 | 0.002 | 0.020 | 0.064 | 0.180 | 0.566 | 0.060 | 0.187 | |
Standard deviation | 0.002 | 0.006 | 0.002 | 0.005 | 0.007 | 0.023 | 0.199 | 0.628 | 0.077 | 0.242 |
Sites/stations (n = 140) | ADD of individuals heavy metals (μg kg−1 day−1) | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
As | Hg | Pb | Cr | Ni | |||||||
Adult | Child | Adult | Child | Adult | Child | Adult | Child | Adult | Child | ||
North | 1 | 0.001 | 0.005 | ND | ND | 0.006 | 0.029 | 0.003 | 0.015 | 0.009 | 0.043 |
2 | 0.001 | 0.005 | ND | ND | 0.003 | 0.015 | 0.004 | 0.020 | 0.006 | 0.032 | |
3 | 0.001 | 0.004 | ND | ND | 0.005 | 0.025 | 0.007 | 0.034 | 0.023 | 0.112 | |
4 | 0.002 | 0.009 | ND | ND | 0.008 | 0.037 | 0.043 | 0.211 | 0.009 | 0.043 | |
5 | 0.001 | 0.005 | ND | ND | 0.003 | 0.017 | 0.019 | 0.095 | 0.011 | 0.054 | |
6 | 0.002 | 0.009 | ND | ND | 0.005 | 0.025 | 0.026 | 0.128 | 0.013 | 0.066 | |
7 | 0.001 | 0.007 | ND | ND | 0.003 | 0.013 | 0.126 | 0.618 | 0.003 | 0.016 | |
South | 8 | 0.001 | 0.006 | ND | ND | 0.003 | 0.013 | 0.003 | 0.013 | 0.006 | 0.028 |
9 | 0.001 | 0.003 | ND | ND | 0.004 | 0.018 | 0.004 | 0.019 | 0.003 | 0.014 | |
10 | 0.001 | 0.007 | ND | ND | 0.003 | 0.017 | 0.027 | 0.134 | 0.008 | 0.038 | |
11 | 0.002 | 0.007 | ND | ND | 0.003 | 0.013 | 0.059 | 0.289 | 0.001 | 0.006 | |
12 | 0.001 | 0.006 | ND | ND | 0.002 | 0.011 | 0.059 | 0.289 | 0.009 | 0.044 | |
13 | 0.001 | 0.005 | ND | ND | 0.004 | 0.021 | 0.046 | 0.224 | 0.009 | 0.046 | |
14 | 0.001 | 0.006 | ND | ND | 0.003 | 0.014 | 0.073 | 0.357 | 0.003 | 0.013 | |
East | 15 | 0.001 | 0.004 | ND | ND | 0.002 | 0.012 | 0.005 | 0.024 | 0.002 | 0.010 |
16 | 0.001 | 0.007 | ND | ND | 0.004 | 0.018 | 0.080 | 0.391 | 0.002 | 0.008 | |
17 | 0.001 | 0.004 | ND | ND | 0.003 | 0.013 | 0.166 | 0.814 | 0.012 | 0.060 | |
18 | 0.002 | 0.010 | ND | ND | 0.004 | 0.022 | 0.003 | 0.016 | 0.013 | 0.064 | |
19 | 0.002 | 0.007 | ND | ND | 0.004 | 0.017 | 0.004 | 0.020 | 0.002 | 0.012 | |
20 | 0.001 | 0.005 | ND | ND | 0.004 | 0.020 | 0.004 | 0.021 | 0.004 | 0.020 | |
21 | 0.001 | 0.006 | ND | ND | 0.005 | 0.026 | 0.030 | 0.146 | 0.006 | 0.030 | |
West | 22 | 0.001 | 0.006 | 0.001 | 0.007 | 0.004 | 0.019 | 0.017 | 0.085 | 0.012 | 0.060 |
23 | 0.003 | 0.014 | ND | ND | 0.009 | 0.047 | 0.045 | 0.222 | 0.094 | 0.460 | |
24 | 0.001 | 0.006 | ND | ND | 0.002 | 0.011 | 0.054 | 0.263 | 0.003 | 0.014 | |
25 | 0.001 | 0.006 | ND | ND | 0.004 | 0.022 | 0.002 | 0.011 | 0.022 | 0.107 | |
26 | 0.002 | 0.008 | ND | ND | 0.004 | 0.019 | 0.008 | 0.041 | 0.021 | 0.104 | |
27 | 0.002 | 0.008 | ND | ND | 0.005 | 0.022 | 0.032 | 0.156 | 0.010 | 0.049 | |
28 | 0.001 | 0.007 | ND | ND | 0.005 | 0.026 | 0.040 | 0.195 | 0.018 | 0.086 | |
Center | 29 | 0.002 | 0.008 | ND | ND | 0.004 | 0.018 | 0.029 | 0.143 | 0.011 | 0.052 |
30 | 0.001 | 0.007 | ND | ND | 0.004 | 0.019 | 0.018 | 0.088 | 0.008 | 0.040 | |
31 | 0.001 | 0.005 | ND | ND | 0.004 | 0.020 | 0.011 | 0.056 | 0.011 | 0.053 | |
32 | 0.001 | 0.006 | 0.001 | 0.007 | 0.004 | 0.020 | 0.056 | 0.276 | 0.007 | 0.033 | |
33 | 0.001 | 0.005 | ND | ND | 0.003 | 0.016 | 0.010 | 0.050 | 0.011 | 0.056 | |
34 | 0.001 | 0.007 | 0.001 | 0.004 | 0.006 | 0.028 | 0.139 | 0.683 | 0.026 | 0.127 | |
35 | 0.001 | 0.005 | ND | ND | 0.005 | 0.022 | 0.003 | 0.014 | 0.008 | 0.042 | |
Mean | 0.001 | 0.006 | 0.0009 | 0.001 | 0.004 | 0.020 | 0.036 | 0.176 | 0.012 | 0.058 | |
Standard deviation | 0.00021 | 0.002 | 0.00083 | 0.002 | 0.001 | 0.007 | 0.040 | 0.195 | 0.015 | 0.075 |
Non-carcinogenic risk
Sites/stations | THQ of individual heavy metals (n = 140) | ∑THQ | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
As | Hg | Pb | Cr | Ni | HI | ||||||||
Adult | Child | Adult | Child | Adult | Child | Adult | Child | Adult | Child | Adult | Child | ||
North | 1 | 0.018 | 0.056 | 0.000 | 0.000 | 0.021 | 0.067 | 0.005 | 0.016 | 0.002 | 0.007 | 0.046 | 0.145 |
2 | 0.017 | 0.053 | 0.000 | 0.000 | 0.011 | 0.033 | 0.007 | 0.021 | 0.002 | 0.005 | 0.036 | 0.112 | |
3 | 0.014 | 0.045 | 0.000 | 0.000 | 0.018 | 0.057 | 0.012 | 0.036 | 0.006 | 0.018 | 0.050 | 0.156 | |
4 | 0.032 | 0.101 | 0.000 | 0.000 | 0.027 | 0.086 | 0.072 | 0.226 | 0.002 | 0.007 | 0.133 | 0.420 | |
5 | 0.018 | 0.056 | 0.000 | 0.000 | 0.012 | 0.039 | 0.032 | 0.102 | 0.003 | 0.009 | 0.065 | 0.206 | |
6 | 0.030 | 0.094 | 0.000 | 0.000 | 0.018 | 0.057 | 0.043 | 0.137 | 0.003 | 0.011 | 0.095 | 0.298 | |
7 | 0.024 | 0.075 | 0.000 | 0.000 | 0.009 | 0.029 | 0.210 | 0.663 | 0.001 | 0.003 | 0.244 | 0.769 | |
South | 8 | 0.020 | 0.064 | 0.000 | 0.000 | 0.009 | 0.029 | 0.004 | 0.014 | 0.001 | 0.004 | 0.035 | 0.111 |
9 | 0.011 | 0.034 | 0.000 | 0.000 | 0.013 | 0.042 | 0.006 | 0.020 | 0.001 | 0.002 | 0.031 | 0.098 | |
10 | 0.024 | 0.075 | 0.000 | 0.000 | 0.012 | 0.039 | 0.046 | 0.143 | 0.002 | 0.006 | 0.084 | 0.264 | |
11 | 0.025 | 0.079 | 0.000 | 0.000 | 0.010 | 0.031 | 0.098 | 0.309 | 0.000 | 0.001 | 0.133 | 0.420 | |
12 | 0.021 | 0.068 | 0.000 | 0.000 | 0.008 | 0.025 | 0.098 | 0.310 | 0.002 | 0.007 | 0.130 | 0.409 | |
13 | 0.017 | 0.053 | 0.000 | 0.000 | 0.015 | 0.047 | 0.076 | 0.240 | 0.002 | 0.007 | 0.110 | 0.348 | |
14 | 0.021 | 0.068 | 0.000 | 0.000 | 0.010 | 0.032 | 0.122 | 0.383 | 0.001 | 0.002 | 0.154 | 0.484 | |
East | 15 | 0.012 | 0.038 | 0.000 | 0.000 | 0.008 | 0.027 | 0.008 | 0.026 | 0.001 | 0.002 | 0.029 | 0.091 |
16 | 0.023 | 0.071 | 0.000 | 0.000 | 0.013 | 0.041 | 0.133 | 0.419 | 0.000 | 0.001 | 0.169 | 0.533 | |
17 | 0.014 | 0.045 | 0.000 | 0.000 | 0.010 | 0.030 | 0.277 | 0.872 | 0.003 | 0.010 | 0.304 | 0.957 | |
18 | 0.033 | 0.105 | 0.000 | 0.000 | 0.016 | 0.050 | 0.006 | 0.018 | 0.003 | 0.010 | 0.058 | 0.183 | |
19 | 0.025 | 0.079 | 0.000 | 0.000 | 0.013 | 0.040 | 0.007 | 0.021 | 0.001 | 0.002 | 0.045 | 0.142 | |
20 | 0.018 | 0.056 | 0.000 | 0.000 | 0.014 | 0.045 | 0.007 | 0.022 | 0.001 | 0.003 | 0.040 | 0.127 | |
21 | 0.019 | 0.060 | 0.000 | 0.000 | 0.019 | 0.060 | 0.050 | 0.156 | 0.002 | 0.005 | 0.089 | 0.281 | |
West | 22 | 0.019 | 0.060 | 0.024 | 0.075 | 0.014 | 0.043 | 0.029 | 0.091 | 0.003 | 0.010 | 0.088 | 0.279 |
23 | 0.046 | 0.146 | 0.000 | 0.000 | 0.034 | 0.107 | 0.075 | 0.238 | 0.023 | 0.074 | 0.179 | 0.565 | |
24 | 0.021 | 0.068 | 0.000 | 0.000 | 0.008 | 0.025 | 0.089 | 0.282 | 0.001 | 0.002 | 0.119 | 0.376 | |
25 | 0.021 | 0.068 | 0.000 | 0.000 | 0.016 | 0.050 | 0.004 | 0.012 | 0.005 | 0.017 | 0.047 | 0.147 | |
26 | 0.027 | 0.086 | 0.000 | 0.000 | 0.014 | 0.043 | 0.014 | 0.044 | 0.005 | 0.017 | 0.060 | 0.190 | |
27 | 0.029 | 0.090 | 0.000 | 0.000 | 0.016 | 0.051 | 0.053 | 0.167 | 0.003 | 0.008 | 0.100 | 0.316 | |
28 | 0.024 | 0.075 | 0.000 | 0.000 | 0.019 | 0.060 | 0.066 | 0.209 | 0.004 | 0.014 | 0.113 | 0.357 | |
Center | 29 | 0.027 | 0.086 | 0.000 | 0.000 | 0.013 | 0.041 | 0.049 | 0.153 | 0.003 | 0.008 | 0.091 | 0.288 |
30 | 0.024 | 0.075 | 0.000 | 0.000 | 0.014 | 0.043 | 0.030 | 0.095 | 0.002 | 0.006 | 0.070 | 0.220 | |
31 | 0.017 | 0.053 | 0.000 | 0.000 | 0.014 | 0.045 | 0.019 | 0.060 | 0.003 | 0.009 | 0.053 | 0.166 | |
32 | 0.019 | 0.060 | 0.024 | 0.075 | 0.015 | 0.046 | 0.094 | 0.295 | 0.002 | 0.005 | 0.153 | 0.482 | |
33 | 0.015 | 0.049 | 0.000 | 0.000 | 0.011 | 0.036 | 0.017 | 0.054 | 0.003 | 0.009 | 0.047 | 0.148 | |
34 | 0.024 | 0.075 | 0.012 | 0.038 | 0.021 | 0.065 | 0.232 | 0.731 | 0.006 | 0.020 | 0.295 | 0.929 | |
35 | 0.017 | 0.053 | 0.000 | 0.000 | 0.016 | 0.051 | 0.005 | 0.015 | 0.002 | 0.007 | 0.040 | 0.125 | |
Mean | 0.022 | 0.069 | 0.002 | 0.005 | 0.015 | 0.046 | 0.060 | 0.189 | 0.003 | 0.009 | 0.101 | 0.318 | |
Standard deviation | 0.007 | 0.021 | 0.006 | 0.018 | 0.005 | 0.017 | 0.066 | 0.209 | 0.004 | 0.012 | 0.069 | 0.219 |
Sites/stations | THQ of individual heavy metals (n = 140) | ∑THQ | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
As | Hg | Pb | Cr | Ni | HI | ||||||||
Adult | Child | Adult | Child | Adult | Child | Adult | Child | Adult | Child | Adult | Child | ||
North | 1 | 0.004 | 0.019 | 0.000 | 0.000 | 0.011 | 0.055 | 0.004 | 0.194 | 0.011 | 0.053 | 0.030 | 0.321 |
2 | 0.004 | 0.018 | 0.000 | 0.000 | 0.006 | 0.028 | 0.005 | 0.026 | 0.008 | 0.039 | 0.023 | 0.111 | |
3 | 0.003 | 0.015 | 0.000 | 0.000 | 0.010 | 0.047 | 0.009 | 0.045 | 0.029 | 0.140 | 0.050 | 0.247 | |
4 | 0.007 | 0.034 | 0.000 | 0.000 | 0.014 | 0.071 | 0.057 | 0.281 | 0.011 | 0.054 | 0.090 | 0.440 | |
5 | 0.004 | 0.019 | 0.000 | 0.000 | 0.007 | 0.032 | 0.026 | 0.127 | 0.014 | 0.068 | 0.050 | 0.246 | |
6 | 0.006 | 0.031 | 0.000 | 0.000 | 0.010 | 0.047 | 0.035 | 0.170 | 0.017 | 0.082 | 0.067 | 0.331 | |
7 | 0.005 | 0.025 | 0.000 | 0.000 | 0.005 | 0.024 | 0.168 | 0.825 | 0.004 | 0.020 | 0.182 | 0.894 | |
South | 8 | 0.004 | 0.021 | 0.000 | 0.000 | 0.005 | 0.024 | 0.003 | 0.017 | 0.007 | 0.035 | 0.020 | 0.097 |
9 | 0.002 | 0.011 | 0.000 | 0.000 | 0.007 | 0.035 | 0.005 | 0.025 | 0.004 | 0.017 | 0.018 | 0.088 | |
10 | 0.005 | 0.025 | 0.000 | 0.000 | 0.007 | 0.032 | 0.036 | 0.179 | 0.010 | 0.048 | 0.058 | 0.284 | |
11 | 0.005 | 0.026 | 0.000 | 0.000 | 0.005 | 0.026 | 0.078 | 0.385 | 0.002 | 0.008 | 0.091 | 0.445 | |
12 | 0.005 | 0.023 | 0.000 | 0.000 | 0.004 | 0.021 | 0.079 | 0.386 | 0.011 | 0.056 | 0.099 | 0.484 | |
13 | 0.004 | 0.018 | 0.000 | 0.000 | 0.008 | 0.039 | 0.061 | 0.299 | 0.012 | 0.057 | 0.084 | 0.413 | |
14 | 0.005 | 0.023 | 0.000 | 0.000 | 0.005 | 0.026 | 0.097 | 0.476 | 0.003 | 0.016 | 0.110 | 0.541 | |
East | 15 | 0.003 | 0.013 | 0.000 | 0.000 | 0.004 | 0.022 | 0.006 | 0.032 | 0.002 | 0.012 | 0.016 | 0.078 |
16 | 0.005 | 0.024 | 0.000 | 0.000 | 0.007 | 0.034 | 0.106 | 0.521 | 0.002 | 0.010 | 0.120 | 0.589 | |
17 | 0.003 | 0.015 | 0.000 | 0.000 | 0.005 | 0.025 | 0.221 | 1.085 | 0.015 | 0.075 | 0.244 | 1.200 | |
18 | 0.007 | 0.035 | 0.000 | 0.000 | 0.008 | 0.042 | 0.004 | 0.022 | 0.016 | 0.079 | 0.036 | 0.178 | |
19 | 0.005 | 0.026 | 0.000 | 0.000 | 0.007 | 0.033 | 0.005 | 0.026 | 0.003 | 0.015 | 0.021 | 0.101 | |
20 | 0.004 | 0.019 | 0.000 | 0.000 | 0.008 | 0.037 | 0.006 | 0.028 | 0.005 | 0.025 | 0.022 | 0.109 | |
21 | 0.004 | 0.020 | 0.000 | 0.000 | 0.010 | 0.050 | 0.040 | 0.194 | 0.008 | 0.038 | 0.061 | 0.302 | |
West | 22 | 0.004 | 0.020 | 0.005 | 0.023 | 0.007 | 0.036 | 0.023 | 0.113 | 0.015 | 0.075 | 0.054 | 0.267 |
23 | 0.010 | 0.049 | 0.000 | 0.000 | 0.018 | 0.089 | 0.060 | 0.296 | 0.117 | 0.575 | 0.205 | 1.008 | |
24 | 0.005 | 0.023 | 0.000 | 0.000 | 0.004 | 0.021 | 0.071 | 0.350 | 0.004 | 0.018 | 0.084 | 0.411 | |
25 | 0.005 | 0.023 | 0.000 | 0.000 | 0.008 | 0.042 | 0.003 | 0.015 | 0.027 | 0.133 | 0.043 | 0.212 | |
26 | 0.006 | 0.029 | 0.000 | 0.000 | 0.007 | 0.035 | 0.011 | 0.055 | 0.026 | 0.130 | 0.051 | 0.249 | |
27 | 0.006 | 0.030 | 0.000 | 0.000 | 0.009 | 0.043 | 0.042 | 0.208 | 0.013 | 0.061 | 0.070 | 0.342 | |
28 | 0.005 | 0.025 | 0.000 | 0.000 | 0.010 | 0.050 | 0.053 | 0.259 | 0.022 | 0.108 | 0.090 | 0.442 | |
Center | 29 | 0.006 | 0.029 | 0.000 | 0.000 | 0.007 | 0.034 | 0.039 | 0.190 | 0.013 | 0.065 | 0.065 | 0.318 |
30 | 0.005 | 0.025 | 0.000 | 0.000 | 0.007 | 0.036 | 0.024 | 0.118 | 0.010 | 0.050 | 0.047 | 0.229 | |
31 | 0.004 | 0.018 | 0.000 | 0.000 | 0.008 | 0.037 | 0.015 | 0.074 | 0.013 | 0.066 | 0.040 | 0.195 | |
32 | 0.004 | 0.020 | 0.005 | 0.023 | 0.008 | 0.038 | 0.075 | 0.368 | 0.008 | 0.042 | 0.100 | 0.491 | |
33 | 0.003 | 0.016 | 0.000 | 0.000 | 0.006 | 0.030 | 0.014 | 0.067 | 0.014 | 0.070 | 0.037 | 0.183 | |
34 | 0.005 | 0.025 | 0.002 | 0.012 | 0.011 | 0.054 | 0.185 | 0.910 | 0.032 | 0.159 | 0.236 | 1.159 | |
35 | 0.004 | 0.018 | 0.000 | 0.000 | 0.009 | 0.042 | 0.004 | 0.019 | 0.011 | 0.052 | 0.027 | 0.131 | |
Mean | 0.005 | 0.023 | 0.000 | 0.002 | 0.008 | 0.038 | 0.048 | 0.240 | 0.015 | 0.073 | 0.075 | 0.375 | |
Standard deviation | 0.001 | 0.007 | 0.001 | 0.006 | 0.003 | 0.014 | 0.053 | 0.258 | 0.019 | 0.094 | 0.059 | 0.285 |
Carcinogenic risk
Sites/stations (n = 140) | Carcinogenic risk (CR) | ||||||||
---|---|---|---|---|---|---|---|---|---|
As | Pb | Cr | Total CR | ||||||
Adult | Child | Adult | Child | Adult | Child | Adult | Child | ||
North | 1 | 7.98E−06 | 1.71E−05 | 2.5E−05 | 4.03E−05 | 3.81E−06 | 6.63E−06 | 3.77E−05 | 6.41E−05 |
2 | 7.44E−06 | 1.60E−05 | 1.2E−05 | 2.29E−05 | 5.18E−06 | 9.02E−06 | 2.56E−05 | 4.79E−05 | |
3 | 6.38E−06 | 1.37E−05 | 2.2E−05 | 3.39E−05 | 8.90E−06 | 1.55E−05 | 3.73E−05 | 6.31E−05 | |
4 | 1.44E−05 | 3.09E−05 | 3.3E−05 | 5.50E−05 | 5.53E−05 | 9.63E−05 | 1.03E−04 | 1.82E−04 | |
5 | 7.98E−06 | 1.71E−05 | 1.5E−05 | 2.62E−05 | 2.50E−05 | 4.35E−05 | 4.81E−05 | 8.68E−05 | |
6 | 1.33E−05 | 2.46E−05 | 2.2E−05 | 3.04E−05 | 3.35E−05 | 5.03E−05 | 6.88E−05 | 1.26E−04 | |
7 | 1.06E−05 | 2.29E−05 | 1.1E−05 | 2.34E−05 | 1.62E−04 | 2.82E−04 | 1.84E−04 | 3.28E−04 | |
South | 8 | 9.04E−06 | 1.94E−05 | 1.1E−05 | 2.19E−05 | 3.30E−06 | 5.75E−06 | 2.36E−05 | 4.71E−05 |
9 | 4.79E−06 | 1.03E−05 | 1.6E−05 | 2.53E−05 | 4.91E−06 | 8.54E−06 | 2.61E−05 | 4.41E−05 | |
10 | 1.06E−05 | 2.29E−05 | 1.5E−05 | 2.03E−05 | 3.51E−05 | 5.11E−05 | 6.09E−05 | 1.12E−04 | |
11 | 1.12E−05 | 2.40E−05 | 1.2E−05 | 2.46E−05 | 7.57E−05 | 1.32E−04 | 9.88E−05 | 1.80E−04 | |
12 | 9.57E−06 | 2.06E−05 | 9.6E−06 | 2.03E−05 | 7.58E−05 | 1.32E−04 | 9.51E−05 | 1.73E−04 | |
13 | 7.44E−06 | 1.60E−05 | 1.8E−05 | 3.01E−05 | 5.88E−05 | 1.02E−04 | 8.47E−05 | 1.48E−04 | |
14 | 9.57E−06 | 2.06E−05 | 1.2E−05 | 2.37E−05 | 9.37E−05 | 1.63E−04 | 1.16E−04 | 2.07E−04 | |
East | 15 | 5.32E−06 | 1.14E−05 | 1.0E−05 | 1.77E−05 | 6.24E−06 | 1.09E−05 | 2.18E−05 | 4.00E−05 |
16 | 1.01E−05 | 2.17E−05 | 1.6E−05 | 2.91E−05 | 1.02E−04 | 1.78E−04 | 1.29E−04 | 2.29E−04 | |
17 | 6.38E−06 | 1.37E−05 | 1.1E−05 | 2.04E−05 | 2.13E−04 | 3.71E−04 | 2.31E−04 | 4.05E−04 | |
18 | 1.49E−05 | 3.20E−05 | 1.9E−05 | 3.74E−05 | 4.31E−06 | 7.50E−06 | 3.87E−05 | 7.69E−05 | |
19 | 1.12E−05 | 2.40E−05 | 1.5E−05 | 2.91E−05 | 5.18E−06 | 9.02E−06 | 3.18E−05 | 6.21E−05 | |
20 | 7.98E−06 | 1.71E−05 | 1.7E−05 | 2.93E−05 | 5.41E−06 | 9.42E−06 | 3.08E−05 | 5.58E−05 | |
21 | 8.51E−06 | 1.43E−05 | 2.3E−05 | 3.75E−05 | 3.52E−05 | 5.24E−05 | 7.01E−05 | 1.22E−04 | |
West | 22 | 8.51E−06 | 1.83E−05 | 1.6E−05 | 2.89E−05 | 2.22E−05 | 3.86E−05 | 4.75E−05 | 8.57E−05 |
23 | 2.07E−05 | 4.46E−05 | 4.1E−05 | 7.09E−05 | 5.82E−05 | 1.01E−04 | 1.20E−04 | 2.17E−04 | |
24 | 9.57E−06 | 2.06E−05 | 9.6E−06 | 2.03E−05 | 6.89E−05 | 5.20E−05 | 8.81E−05 | 1.61E−04 | |
25 | 9.57E−06 | 2.06E−05 | 1.9E−05 | 3.32E−05 | 2.89E−06 | 5.03E−06 | 3.19E−05 | 5.88E−05 | |
26 | 1.22E−05 | 2.63E−05 | 1.6E−05 | 3.14E−05 | 1.09E−05 | 1.89E−05 | 3.96E−05 | 7.66E−05 | |
27 | 1.28E−05 | 2.74E−05 | 2.0E−05 | 3.63E−05 | 4.09E−05 | 5.11E−05 | 7.36E−05 | 1.35E−04 | |
28 | 1.06E−05 | 2.29E−05 | 2.3E−05 | 3.89E−05 | 5.10E−05 | 6.88E−05 | 8.49E−05 | 1.51E−04 | |
Center | 29 | 1.22E−05 | 2.63E−05 | 1.5E−05 | 3.04E−05 | 3.74E−05 | 6.51E−05 | 6.54E−05 | 1.22E−04 |
30 | 1.06E−05 | 2.29E−05 | 1.6E−05 | 3.05E−05 | 2.32E−05 | 4.03E−05 | 5.06E−05 | 9.37E−05 | |
31 | 7.44E−06 | 1.60E−05 | 1.7E−05 | 2.88E−05 | 1.46E−05 | 2.54E−05 | 3.95E−05 | 7.02E−05 | |
32 | 8.51E−06 | 1.83E−05 | 1.7E−05 | 3.03E−05 | 7.23E−05 | 1.26E−04 | 9.87E−05 | 1.74E−04 | |
33 | 6.91E−06 | 1.49E−05 | 1.4E−05 | 2.39E−05 | 1.32E−05 | 2.29E−05 | 3.41E−05 | 6.17E−05 | |
34 | 1.06E−05 | 2.29E−05 | 2.5E−05 | 4.16E−05 | 1.79E−04 | 3.11E−04 | 2.15E−04 | 3.76E−04 | |
35 | 7.44E−06 | 1.60E−05 | 1.9E−05 | 3.19E−05 | 3.67E−06 | 6.39E−06 | 3.09E−05 | 5.43E−05 | |
Mean | 9.78E−06 | 2.10E−05 | 1.7E−05 | 3.12E−05 | 4.61E−05 | 8.03E−05 | 7.38E−05 | 1.33E−04 | |
Standard deviation | 3.07E−06 | 6.61E−06 | 6.5E−06 | 1.03E−05 | 5.20E−05 | 9.05E−05 | 5.25E−05 | 9.20E−05 |