Multigenerational effects of ecotoxicological interaction between arsenic and silver nanoparticles

Despite arsenic being one of the most widely distributed toxicants over the world, its reported occurrence in Latin America is relatively low when compared to North America, Europe, and Asia. Regardless, it still requires proper assessment; especially considering its potential interaction with other new contaminants, such as nanomaterials. In the present study, a brief introduction to arsenic contamination in Latin America is made, its main methods of intake by humans are described, and concerns regarding its interaction with other contaminants, especially nanomaterials, are presented. A multigenerational approach through five generations of Caenorhabditis elegans was performed to assess, at ecotoxicological relevant concentrations, the toxic effects of arsenic/nanomaterial interaction through the measurement of biochemical and physiological parameters. The reactive oxygen species (ROS) and lipid peroxidation levels were assessed, levels of reduced glutathione (GSH) determined, and the enzyme activities of glutamate cysteine ligase (GCL), glutathione-S-transferase (GST), and catalase (CAT) were measured. Fertility, reproduction, and growth parameters were also assessed and compared. A nanomaterial modulatory effect was found to accentuate the toxicity of arsenic on some of the most important enzymes in the antioxidant defense system; deleterious effects were also found in the development and reproduction of the animals throughout the generations. This work shows that multigenerational approaches can unveil toxic effects that would remain cryptic when evaluated in only one generation.