Table 2.
Summary of trace metals concentrations in surface sediments of the ZMNNR.
| Time of sampling | Number of samplings | Concentrations (mg/kg) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Cu | Cd | Pb | Cr | Zn | As | Hg | |||
| This study | 2013 | 17a | 21.47 ± 2.23 | 0.064 ± 0.034 | 41.97 ± 4.09 | 38.11 ± 26.26 | 140.78 ± 10.25 | 24.73 ± 1.67 | 0.019 ± 0.019 |
| 12b | 19.41 ± 3.73 | 0.076 ± 0.046 | 46.93 ± 7.10 | 19.55 ± 7.74 | 133.16 ± 8.61 | 25.55 ± 4.44 | 0.026 ± 0.019 | ||
| Previous survey | 2007 | 17 | 21.04 ± 6.13 | 0.336 ± 0.055 | 63.20 ± 3.04 | 61.50 ± 18.03 | 127.65 ± 4.74 | 14.29 ± 1.00 | 0.034 ± 0.026 |
| Jingchun et al., 2010 [35] | 2004 | 7c | 30.28 ± 4.70 | 0.21 ± 0.03 | 53.91 ± 4.83 | — | 127.51 ± 13.92 | — | — |
| 7d | 28.79 ± 5.59 | 0.30 ± 0.01 | 62.81 ± 9.44 | — | 143.96 ± 12.37 | — | — | ||
| 7e | 36.42 ± 5.74 | 0.36 ± 0.08 | 70.09 ± 3.96 | — | 159.56 ± 9.88 | — | — | ||
| Backgroundf | 5.40 | 0.03 | 16.20 | — | 33.90 | — | — | ||
| ISQG low | 65 | 1.5 | 50 | 80 | 200 | 20 | 21 | ||
| ISQG high | 270 | 10 | 218 | 370 | 410 | 70 | 100 | ||
Data are means ± standard deviation of sites.
ISQG, Interim Sediment Quality Guidelines. The guidelines define the ISQG-high and ISQG-low values, which represent the lower 10th percentile and 50th percentile of chemical concentrations associated with adverse biological effects, based on the results of sediment toxicity testing [37].
aThe sampling sites in the intertidal zone.
bThe sampling sites in the subtidal zone.
cThe sampling sites in the mudflat.
dThe sampling sites in the forest edge.
eThe sampling sites in the forest.
fThe background levels of trace metals obtained from a subsample of 41 surface sediments in a location in continental shelf area of south Taiwan Strait.