Health effects of silver nanoparticles and silver ions

Abstract

The health effects of silver nanoparticles (AgNPs) have not been well investigated, despite AgNPs now being widely used in consumer products. We introduce living environment, analysis, metabolic behavior, toxicity, and human health effect of AgNPs in comparison to silver nitrate (AgNO3). The American Conference of Governmental Industrial Hygienists (ACGIH) has established separate threshold limit values (TLV) for metallic silver (0.1 mg/m3) and soluble compounds of silver (0.01 mg/m3). Argyria and argyrosis are chronic disorders of skin microvessels and eyes in humans, and these disorders reportedly develop following extended oral and inhalational exposure to Ag. In mammals, AgNO3 and AgNPs increased the number of the total cells, neutrophils, and pro-inflammatory cytokine production "IL-1β," and these were distributed in the lung, kidney, and liver. The amount of Ag in the metallothionein (MT)-bound form was related in cellular behavior and toxicity of AgNPs and AgNO3. The cytotoxic effect of AgNPs is a simple function of neither the number nor total surface area. Although the effect may vary among the cell types and the culture conditions, AgNPs were transported to lysosomes and only gradually dissolved in mammals, causing milder inflammatory stimulation.