Table 1.
Individual-Metal Toxicity Data for Metal Concentrations and Ion Activities (M2+ + MOH+) for Cd, Cu, Ni, and Zna
| metal | metal concentration
|
ion activity
|
n | ||
|---|---|---|---|---|---|
| EC50 (M) (95% CI) | slope (95% CI) | EC50 (M) (95% CI) | slope (95% CI) | ||
| Cd | 8.36 × 10−7 A (5.80–10.91 × 10−7) | 1.68 A (1.21–2.15) | 2.98 × 10−7 A (2.67–3.30 × 10−7) | 1.47 A (1.34–1.59) | 8 |
| Cu | 1.41 × 10−6 B (1.21–1.70 × 10−6) | 6.29 B (3.44–9.15) | 1.74 × 10−8 B (1.40–2.09 × 10−8) | 3.92 B (2.99–4.85) | 5 |
| Ni | 3.14 × 10−5 C (2.34–3.95 × 10−5) | 2.85 C (2.30–3.40) | 9.92 × 10−6 C (8.92 × 10−6–1.09 × 10−5) | 3.04 B (2.77–3.31) | 8 |
| Zn | 1.21 × 10−5 D (0.69–1.74 × 10−5) | 1.70 A (1.25–2.16) | 3.65 × 10−6 D (3.12–4.19 × 10−6) | 1.38 A (1.26–1.50) | 5 |
a
The average 48 h median effect concentration (EC50), slope of log–logistic concentration–response curve, and number of toxicity tests conducted (n) is reported for the immobilization of Daphnia magna neonates exposed to each of the metals in repeated static, non-renewal lethality tests. Numbers in parentheses are the 95% confidence interval (CI) on the EC50 or slope. Different capital letters within a column indicate statistically significant (p ≤ 0.05) differences among the metals.