Table 5 Comparison of the concentrations of six heavy metals in rice grain (mg kg−1) in this research with the data from some previous studies.
Cd (mg kg−1) | Pb (mg kg−1) | Ni (mg kg−1) | Cr (mg kg−1) | Zn (mg kg−1) | Cu (mg kg−1) | |
|---|---|---|---|---|---|---|
Data (n = 86) | ||||||
Max | 1.094 | 0.483 | 14.55 | 1.34 | 58.67 | 6.75 |
Min | 0.028 | 0.048 | 0.28 | 0.05 | 19.22 | 2.33 |
Median | 0.233 | 0.175 | 1.14 | 0.38 | 29.64 | 4.17 |
Statistics | ||||||
Mean | 0.163 | 0.148 | 0.88 | 0.31 | 27.67 | 4.04 |
SD | 0.206 | 0.094 | 1.57 | 0.25 | 7.89 | 0.91 |
CV | 88.1% | 53.5% | 137.8% | 66.9% | 26.6% | 21.8% |
References | ||||||
Guidelines a | 0.2 | 0.2 | –b | 1.0 | – | – |
Exceeding | 34% | 30% | – | 6% | – | – |
Mean values and range of other areas | ||||||
Zhejiang Provincec (n = 248) | 0.037 | 0.060 | – | – | – | – |
LOD-0.112 | 0.005–0.220 | – | – | – | – | |
Wenling (n = 219) | 0.132 | – | 0.223 | – | 17.4 | 2.46 |
0.011–2.50 | – | 0.014–0.959 | – | 10.3–31.4 | 0.580–5.05 | |
Changshu (n = 155) | 0.019 | 0.171 | – | 0.292 | 19.1 | 3.84 |
LOD-0.201 | LOD-0.957 | – | 0.024–0.742 | 9.10–28.3 | 0.87–7.77 | |
