Toxicity of metal mixtures to the Pacific white shrimp Litopenaeus vannamei postlarvae.
According to the literature, the safe level of a toxic substance for any given organism may be calculated from its median lethal concentration multiplied by a suitable application factor (AF: usually 0.1 and 0.01). The medial lethal concentrations for Litopenaeus vannamei postlarvae exposed to the mixtures in equitoxic proportions of Cd-Hg, Hg-Zn and Hg-Pb were close to one order of magnitude lower than the values calculated from individual toxicity tests, indicating a synergistic effect, while the mixture Cd-Zn showed an antagonistic effect. Exposure to the mixture of Cu, Fe, Mn, Zn, Cd, Hg and Pb caused 63.3% and 100% mortality after 21 and 13 days for 0.05 and 0.1 AF, showing that environmental safe concentrations of toxicants should not be calculated from individual toxicity tests.
Frías-Espericueta
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MG
Autonomous University of Sinaloa, Faculty of Marine Science, Environmental Studies Laboratory, P.O. Box 1132, Mazatlán, Sinaloa 82000, Mexico.
Voltolina
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Osuna-López
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Izaguirre-Fierro
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D000818:Animals; D017756:Aquaculture; D004435:Eating / Q000187:drug effects; D019216:Metals, Heavy / Q000633:toxicity*; D018978:Molting / Q000187:drug effects; D010140:Pacific Ocean; D033561:Penaeidae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D012623:Seawater / Q000737:chemistry*; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D019216:Metals, Heavy; D014874:Water Pollutants, Chemical