Toxicity of Silver Nanoparticles at the Air-Liquid Interface

Amara L Holder,Linsey C Marr

doi:10.1155/2013/328934

Abstract

Silver nanoparticles are one of the most prevalent nanomaterials in consumer products. Some of these products are likely to be aerosolized, making silver nanoparticles a high priority for inhalation toxicity assessment. To study the inhalation toxicity of silver nanoparticles, we have exposed cultured lung cells to them at the air-liquid interface. Cells were exposed to suspensions of silver or nickel oxide (positive control) nanoparticles at concentrations of 2.6, 6.6, and 13.2 μg cm−2 (volume concentrations of 10, 25, and 50 μg ml−1) and to 0.7 μg cm−2 silver or 2.1 μg cm−2 nickel oxide aerosol at the air-liquid interface. Unlike a number of in vitro studies employing suspensions of silver nanoparticles, which have shown strong toxic effects, both suspensions and aerosolized nanoparticles caused negligible cytotoxicity and only a mild inflammatory response, in agreement with animal exposures. Additionally, we have developed a novel method using a differential mobility analyzer to select aerosolized nanoparticles of a single diameter to assess the size-dependent toxicity of silver nanoparticles.

Highlights

As the number of nanotechnology-based consumer products in the marketplace grows, so too does the potential for inhalation exposures to nanomaterials
Experimental studies have shown that engineered nanoparticles released by sprays and powders can potentially deposit in the respiratory system [8,9,10,11]
Characterizing the hazard associated with inhaling silver nanoparticles is urgently needed because of their widespread prevalence in consumer products and the high likelihood of their aerosolization during product use. e American Conference of Governmental Industrial Hygienists (ACGIH) has set a threshold limit value of 0.01 mg m−3 for soluble silver and 0.1 mg m−3 for insoluble silver. ese values were determined from epidemiology studies on workers exposed to silver dust, where few adverse health effects were observed apart from the development of argyria [46]

Summary

Introduction

As the number of nanotechnology-based consumer products in the marketplace grows, so too does the potential for inhalation exposures to nanomaterials. Experimental studies have shown that engineered nanoparticles released by sprays and powders can potentially deposit in the respiratory system [8,9,10,11]. Due to their antibacterial qualities, silver nanoparticles are widely used in consumer products. Inhalation exposures are likely to occur with personal hygiene and cleaning products that are intended to be sprayed. Because these consumer products release silver nanoparticles into the breathing zone of consumers, it is imperative to determine the potential hazards associated with inhaling silver nanoparticles

Methods

Results

Conclusion