Toxicity of silver nanoparticles to green algae M. aeruginosa and alleviation by organic matter.

Silver nanoparticles (AgNPs) have been increasingly used in a wide range of consumer products over the last decade. The release of AgNPs into aquatic ecosystems raises concerns about their safety and environmental toxicity, which have been the subject of recent studies. Herein, we assess the toxicity of AgNPs to the common algae Microcystis. aeruginosa. A toxicological response by M. aeruginosa was exhibited at an early stage of exposure to AgNPs, which were also toxic to its growth, photosynthetic, and membrane systems. The attachment of AgNPs to microalgae is likely the main mechanism by which it damages cell membranes. Dissolved Ag ions, originating from internalized AgNPs, seem to directly target the photosynthetic system. We also found that several humus-related indicators of water quality (HIX and β/α) were related to reduced AgNPs toxicity. Graphical abstract.