Acute toxicity of 31 different nanoparticles to zebrafish (Danio rerio) tested in adulthood and in early life stages – comparative study

At present, nanoparticles are beginning to influence our lives in many ways and understanding the environmental health and safety aspect of nanomaterials has become a crucial issue. The aim of the work was to assess and compare the acute toxicity of 31 different nanomaterials to fish mature individuals Danio rerio with that to fish early life stages on using evaluation of the 48- and 96- hour LC₅₀ values. A further aim was to evaluate teratogenicity of the nanoparticles tested to fish eggs. The nanoparticles tested were: 8 pure metals, 10 metal oxides, 5 other metal compounds and their mixtures, 2 silicon compounds, 3 calcium compounds, and 3 carbon compounds. Using 48-h and 96-h tests of acute toxicity (according to OECD 203), we evaluated mortality data, LC₅₀ values, occurrence of malformations, as well as hatching time. In our study, 6 kinds of nanoparticles - calcium oxide, copper, copper in the form of oxide and CuZnFe₄O₄, magnesium oxide, and nickel - caused cumulative mortality. Two kinds of nanoparticles - copper and silver - were toxic for fish with LC₅₀ values of approximately 3 mg/L. We did not observe marked differences between the 48-hour and 96-hour acute toxicity LC₅₀ values, yet the possibility to evaluate hatching time in the 96-h acute fish toxicity test seems to be an advantage against that of the 48-hour toxicity.