Ultrafine Particles Emitted through Routine Operation of a Hairdryer.

Particulate matter is a large concern for human health. Fine and ultrafine particulate matter has been shown to negatively impact human health; for example, it causes cardiopulmonary diseases. Current regulation targets the size of the particles, but composition also impacts toxicity. Indoor sources of air pollution pose unique challenges for human health due to the potential for human exposure to high concentrations in confined spaces. In this work, six hairdryers were each operated within a plexiglass chamber, and their emissions were analyzed with transmission electron microscopy and energy-dispersive spectroscopy. All hairdryers were found to emit ultrafine iron, carbon, and copper. In addition, emissions from two hairdryers primarily contained silver nanoparticles in the ultrafine range (<100 nm). The ultrafine particle emission rates for the hairdryers that did not contain silver were measured and found to be lower than ultrafine particle emissions by gas stoves and electric burners. Based on their size, these particles can either remain in the lung or enter the bloodstream after inhalation and potentially cause long-term health effects.