Effectiveness of hand washing on the removal of iron oxide nanoparticles from human skin ex vivo

Abstract

In this study, the effectiveness of washing with soap and water in removing nanoparticles from exposed skin was investigated. Dry, nanoscale hematite (α-FeO) or maghemite (γ-FeO) powder, with primary particle diameters between 20-30 nm, were applied to two samples each of fresh and frozen ex vivo human skin in two independent experiments. The permeation of nanoparticles through skin, and the removal of nanoparticles after washing with soap and water were investigated. Bare iron oxide nanoparticles remained primarily on the surface of the skin, without penetrating beyond the stratum corneum. Skin exposed to iron oxide nanoparticles for 1 and 20 hr resulted in removal of 85% and 90%, respectively, of the original dose after washing. In the event of dermal exposure to chemicals, removal is essential to avoid potential local irritation or permeation across skin. Although manufactured at an industrial scale and used extensively in laboratory experiments, limited data are available on the removal of engineered nanoparticles after skin contact. Our finding raises questions about the potential consequences of nanoparticles remaining on the skin and whether alternative washing methods should be proposed. Further studies on skin decontamination beyond use of soap and water are needed to improve the understanding of the potential health consequences of dermal exposure to nanoparticles.

A Case Study of Brass Foundry Workers’ Estimated Lead (Pb) Body Burden from Different Exposure Routes

“…A recently published study show that workers’ glove use did not affect the amount on cobalt deposited on skin in a hard metal facility due to the factors mentioned above ( Kettelarij et al , 2018b ). Furthermore, the efficiency of washing off metals from the skin has been investigated in some studies, showing that cobalt, chromium, iron, nickel, and lead, remain on the skin surface even after thorough cleaning ( Linnainmaa and Kiilunen, 1997 ; Sato and Yano, 2006 ; Liden et al , 2008 ; Lewinski et al , 2017 ). In addition, it is well known that repeated and intensive hand washing can damage the skin’s barrier function through dehydration, friction and the influence of chemicals in the soaps used ( Hamnerius et al , 2018 ).…”

Numerical Computation of Hydrodynamic Characteristics of an Automated Hand-Washing System

“…The volume fractions of NCGs within steam sterilizers, according to many indexes such as fluid flow, temperature, and heat transfer, are separated in time and space. Lewinski et al [16] studied the effectiveness of iron oxide nanoparticles to remove the bacteria from human skin. The research indicated γ − Fe 2 O 3 , ZnO nanoparticles have a remarkable ability to remove pathogens attached to the surface of human skin.…”