Phytotoxicity tests with higher plants for environmental risk assessment

Phytotoxicity test were performed to evaluate their application in environmental monitoring on different substrates e.g. commercial detergents (D1, D2) and surface water from the dismissed Cu and Fe mine of Libiola (NW Italy), respectively. Seeds of Vicia faba were grown in 0, 10, 30, 60, 100 g/l of D1 and D2. Number of germinated seeds and root length, Germination iNDEX (G1) and growth inhibition (EC₅₀) were considered. The Vicia test showed no significant differences between D1 and D2, with an EC₅₀ of 13 g/l (11-15 95% C1) for D1 and 16 g/l (14-19 95% C1) for D2. These data were confirmed by G1<50% at 18, 26, 30, 60 and 100 g/l. Onion bulbs of Allium cepa, were tested at 0, 6 12, 25, 50 and 100% of mine water. Root length inhibition (EC₅₀) and Mitotic Index (MI) were evaluated. The Allium test showed a statistically significant inhibition of root growth at 50% and 100%. The root growth percentage decreased in a dose-related manner, with an EC₅₀ of 87%. The MI decreased significantly only at 100% (undiluited mine water). Both phytotoxicity tests should be considered as valid ecotoxicological indicators for health and environment.