Assessment of side-effects by Ludox TMA silica nanoparticles following a dietary exposure on the bumblebee Bombus terrestris

AbstractWe assessed lethal and sublethal side-effects of Ludox TMA silica nanoparticles on a terrestrial pollinator, Bombus terrestris (Linnaeus), via a dietary exposure. Dynamic light scattering analysis confirmed that silica Ludox TMA nanoparticles remained in suspension in the drinking sugar water. Exposure of bumblebee microcolonies during 7 weeks to the different nanoparticle concentrations (high: 34, 170 and 340 mg/l and low: 34 and 340 μg/l) did not cause worker mortality compared to the controls. Also no effect on the worker foraging behavior was observed after exposure to nanoparticles concentrations up to 340 μg/l. In contrast, the high concentrations (≥34 mg/l) resulted in a total loss of reproduction. Using histological analysis we confirmed severe midgut epithelial injury in intoxicated workers (≥34 mg/l). Despite the fact that these concentrations are much higher than the predicted environmental concentrations, precaution is still needed as information regarding their fate in the terrestrial...