Inflammatory response of mice following inhalation exposure to iron and copper nanoparticles

Health hazard evaluation report: evaluation of instructor and range officer exposure to emissions from copper-based frangible ammunition at a military firing range.

“…The toxicity of nano-sized copper has been studied in cell cultures and in animals. These studies concluded that, because of the small size and increased surface area of the nano-sized particles, inhalation exposure could result in cellular uptake, formation of reactive oxidative species and subsequent inflammation and irritation [Pettibone et al 2008;Wang et al 2012]. This may explain why health symptoms were reported, yet no mass-based OEL was exceeded.…”

Kupfer und seine anorganischen Verbindungen [MAK Value Documentation in German language, 2014]

“…Jedoch werden unter den meisten Expositionsbedingungen Kupfer-Aerosole mit eher größeren Partikelgrößen (>1 μm) freigesetzt, die üblicherweise nicht zum typischen Metallrauchfieber führen. Metallrauchfieber wird bei Exposition gegen feinen Rauch (Partikelgröße <1 μm) von Metalloxiden hervorgerufen (Borak 2000 ( Kim et al 2011;Pettibone et al 2008). Da die Studien mit Nanopartikeln durchgeführt wurden, werden sie nicht zur Bewertung herangezogen.…”

Human inhalation exposure to iron oxide particles

“…Pettibone et al exposed mice 4 h per day for 2 weeks to γ-Fe 2 O 3 nanoparticle concentrations as high as 7.6 mg/m 3 and found increased cell counts in BAL fluid, which returned to baseline 3 weeks post exposure, with no acute toxicity or signs of pathology [75]. In a study by Zhou et al, rats exposed 6 h per day for 3 days to 90 µg/m 3 of γ-Fe 2 O 3 nanoparticles presented with mild respiratory effects measured by BAL (i.e., induction of ferritin, increased lavage protein, elevated oxidative stress and inflammatory markers) but no significant cytotoxicity [77].…”

“…No acute toxicity was reported in the studies that tested micron sized particles [72][73][74]. While oxidative stress and inflammation were reported in some nanoparticle inhalation studies, these experiments involved multiple exposures or very high (orders of magnitude above the current TLV) exposure concentrations [75][76][77]. Beyond acute toxicity, a comprehensive carcinogenicity evaluation of several types of iron oxides was conducted in rats by Steinhoff et al [78].…”