Table 5. Hazard quotient (HQ), dermal permeability coefficient (Kp), and reference dose (RfD) for dissolved heavy metals in the Zhujiang River.
| HQingestion | HQdermal | HI = ΣHQs | Kpa cm h−1 | RfDingestionb,c μg kg−1day−1 | RfDdermalb,c μg kg−1day−1 | ||||
|---|---|---|---|---|---|---|---|---|---|
| Adult | Children | Adult | Children | Adult | Children | ||||
| Low flow season | |||||||||
| V | 5.83 × 10−2 | 8.70 × 10−2 | 6.08 × 10−2 | 1.80 × 10−1 | 1.19 × 10−1 | 2.67 × 10−1 | 2.00 × 10−3 | 1 | 0.01 |
| Cr | 6.26 × 10−2 | 9.34 × 10−2 | 1.31 × 10−2 | 3.85 × 10−2 | 7.56 × 10−2 | 1.32 × 10−1 | 1.00 × 10−3 | 3 | 0.075 |
| Mn | 5.10 × 10−4 | 7.62 × 10−4 | 6.66 × 10−5 | 1.96 × 10−4 | 5.77 × 10−4 | 9.58 × 10−4 | 1.00 × 10−3 | 24 | 0.96 |
| Co | 1.02 × 10−2 | 1.53 × 10−2 | 1.07 × 10−4 | 3.15 × 10−4 | 1.03 × 10−2 | 1.56 × 10−2 | 4.00 × 10−4 | 0.3 | 0.06 |
| Ni | 3.27 × 10−3 | 4.89 × 10−3 | 8.55 × 10−5 | 2.52 × 10−4 | 3.36 × 10−3 | 5.14 × 10−3 | 2.00 × 10−4 | 20 | 0.8 |
| Cu | 6.16 × 10−4 | 9.19 × 10−4 | 1.61 × 10−5 | 4.74 × 10−5 | 6.32 × 10−4 | 9.67 × 10−4 | 1.00 × 10−3 | 40 | 8 |
| Mo | 3.45 × 10−3 | 5.15 × 10−3 | 9.47 × 10−5 | 2.79 × 10−4 | 3.54 × 10−3 | 5.43 × 10−3 | 2.00 × 10−3 | 5 | 1.9 |
| Cd | 2.40 × 10−3 | 3.58 × 10−3 | 2.51 × 10−4 | 7.39 × 10−4 | 2.65 × 10−3 | 4.32 × 10−3 | 1.00 × 10−3 | 0.5 | 0.025 |
| Ba | 2.02 × 10−3 | 3.01 × 10−3 | 1.50 × 10−4 | 4.44 × 10−4 | 2.17 × 10−3 | 3.46 × 10−3 | 1.00 × 10−3 | 200 | 14 |
| Pb | 1.10 × 10−3 | 1.65 × 10−3 | 1.92 × 10−6 | 5.66 × 10−6 | 1.10 × 10−3 | 1.65 × 10−3 | 1.00 × 10−4 | 1.4 | 0.42 |
| High flow season | |||||||||
| V | 7.09 × 10−2 | 1.06 × 10−1 | 7.40 × 10−2 | 2.18 × 10−1 | 1.45 × 10−1 | 3.24 × 10−1 | 2.00 × 10−3 | 1 | 0.01 |
| Cr | 6.87 × 10−2 | 1.03 × 10−1 | 1.43 × 10−2 | 4.23 × 10−2 | 8.30 × 10−2 | 1.45 × 10−1 | 1.00 × 10−3 | 3 | 0.075 |
| Mn | 4.54 × 10−4 | 6.78 × 10−4 | 5.93 × 10−5 | 1.75 × 10−4 | 5.13 × 10−4 | 8.53 × 10−4 | 1.00 × 10−3 | 24 | 0.96 |
| Co | 9.86 × 10−3 | 1.47 × 10−2 | 1.03 × 10−4 | 3.04 × 10−4 | 9.96 × 10−3 | 1.50 × 10−2 | 4.00 × 10−4 | 0.3 | 0.06 |
| Ni | 2.84 × 10−3 | 4.25 × 10−3 | 7.43 × 10−5 | 2.19 × 10−4 | 2.92 × 10−3 | 4.47 × 10−3 | 2.00 × 10−4 | 20 | 0.8 |
| Cu | 5.27 × 10−4 | 7.87 × 10−4 | 1.38 × 10−5 | 4.06 × 10−5 | 5.41 × 10−4 | 8.28 × 10−4 | 1.00 × 10−3 | 40 | 8 |
| Mo | 2.41 × 10−3 | 3.60 × 10−3 | 6.63 × 10−5 | 1.95 × 10−4 | 2.48 × 10−3 | 3.80 × 10−3 | 2.00 × 10−3 | 5 | 1.9 |
| Cd | 1.80 × 10−3 | 2.69 × 10−3 | 1.88 × 10−4 | 5.55 × 10−4 | 1.99 × 10−3 | 3.24 × 10−3 | 1.00 × 10−3 | 0.5 | 0.025 |
| Ba | 1.71 × 10−3 | 2.56 × 10−3 | 1.28 × 10−4 | 3.77 × 10−4 | 1.84 × 10−3 | 2.93 × 10−3 | 1.00 × 10−3 | 200 | 14 |
| Pb | 8.50 × 10−4 | 1.27 × 10−3 | 1.48 × 10−6 | 4.37 × 10−6 | 8.52 × 10−4 | 1.27 × 10−3 | 1.00 × 10−4 | 1.4 | 0.42 |
| Low flow season, calculated by the maximal concentrations | |||||||||
| Mn | 3.05 × 10−1 | 4.56 × 10−1 | 3.98 × 10−2 | 1.17 × 10−1 | 3.45 × 10−1 | 5.73 × 10−1 | 1.00 × 10−3 | 24 | 0.96 |
| Mo | 5.25 × 10−1 | 7.84 × 10−1 | 1.44 × 10−2 | 4.25 × 10−2 | 5.39 × 10−1 | 8.26 × 10−1 | 2.00 × 10−3 | 5 | 1.9 |