Developmental effects on Daphnia magna induced by titanium dioxide and iron oxide mixtures

Abstract

Developmental effects of a binary mixture of nanoparticles (NPs) composed of Titanium dioxide (TiO _2 ) and iron oxide (Fe _2 O _3 ) were identified in Daphnia magna using a chronic toxicity test. Survival, growth, reproduction, and age at first brood were measured throughout 21 days of exposure. Results from this study demonstrated that mixture exposure to NPs (TiO _2 and Fe _2 O3) significantly affects the development of D. magna to maturation and disturbs the reproductive performance in a dose-dependent manner and beginning from the lower dose. Mortality recorded in control group (1 ± 0.365) was significantly lower than in experimental groups (6.94 ± 0.193, 7.19 ± 0.188, 7.62 ± 0.125, 7.62 ± 0.155 individual, in C1, C2, C3, and C4, respectively). Moreover, swimming performances (F _4, 35 = 112.9, df = 4, p < 0.0001) and heart rate (F _4, 25 = 19.37, df = 4, p < 0.0001) were also affected. In conclusion, the interaction of binary mixtures can exacerbate toxicological effects that have significant implications for appropriately assessing the ecotoxicological effects of emerging pollutants. Further investigation and the results reported in the present study will be useful in environmental policies.

Keywords

• behavior
• chronic toxicity
• Daphnia magna
• iron oxide
• titanium dioxide
• mixtures