Histopathological changes in zebrafish exposed to sublethal concentrations of 89 nm silver nanoparticles for application in environmental diagnostics

Abstract

The use of biomarkers as indicators of environmental contamination has been shown to be an excellent indicator of changes in biota. Histopathological lesions are commonly used in biomonitoring studies as they provide information regarding both acute and chronic exposure. The use of nanoparticle materials has been widespread in recent years. However, not much is known about their ecological effects on the natural environment. Thus, the aim of this study was to assess the sublethal effects of silver nanoparticles (AgNP) with mean diameters of 89 nm in the zebrafish Danio rerio by the determination of the LC50; 48 h and histopathological assays in gills. The obtained LC50; 48 h was 8.18 µgL−1. The histopathological gill assessment showed primary responses indicative of acute damage as aneurysms (32.76%), hyperplasia (20.69%) and partial (30.17%) and total lamellar fusion (6.9%) of secondary lamellae. No deposition of AgNP was observed in any tested sample gills, suggesting other organs target to absorption and detoxification. In fact, the AgNP causes sublethal damage in the gills of zebrafish but is not able to accumulate in this tissue. Finally, the data shown in this study contribute to the construction of a database on the AgNP exposure in aquatic organisms.