Tizia Thoma, Lan Ma-Hock, Steffen Schneider, Naveed Honarvar, Silke Treumann, Sibylle Groeters, Volker Strauss, Heike Marxfeld, Dorothee Funk-Weyer, Svenja Seiffert, Wendel Wohlleben, Martina Dammann, Karin Wiench, Noömi Lombaert, Christine Spirlet, Marie Vasquez, Nicole Dewhurst, Robert Landsiedel
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引用次数: 0
Abstract
Background: Significant variations exist in the forms of ZnO, making it impossible to test all forms in in vivo inhalation studies. Hence, grouping and read-across is a common approach under REACH to evaluate the toxicological profile of familiar substances. The objective of this paper is to investigate the potential role of dissolution, size, or coating in grouping ZnO (nano)forms for the purpose of hazard assessment. We performed a 90-day inhalation study (OECD test guideline no. (TG) 413) in rats combined with a reproduction/developmental (neuro)toxicity screening test (TG 421/424/426) with coated and uncoated ZnO nanoforms in comparison with microscale ZnO particles and soluble zinc sulfate. In addition, genotoxicity in the nasal cavity, lungs, liver, and bone marrow was examined via comet assay (TG 489) after 14-day inhalation exposure.
Results: ZnO nanoparticles caused local toxicity in the respiratory tract. Systemic effects that were not related to the local irritation were not observed. There was no indication of impaired fertility, developmental toxicity, or developmental neurotoxicity. No indication for genotoxicity of any of the test substances was observed. Local effects were similar across the different ZnO test substances and were reversible after the end of the exposure.
Conclusion: With exception of local toxicity, this study could not confirm the occasional findings in some of the previous studies regarding the above-mentioned toxicological endpoints. The two representative ZnO nanoforms and the microscale particles showed similar local effects. The ZnO nanoforms most likely exhibit their effects by zinc ions as no particles could be detected after the end of the exposure, and exposure to rapidly soluble zinc sulfate had similar effects. Obviously, material differences between the ZnO particles do not substantially alter their toxicokinetics and toxicodynamics. The grouping of ZnO nanoforms into a set of similar nanoforms is justified by these observations.
期刊介绍：
Particle and Fibre Toxicology is an online journal that is open access and peer-reviewed. It covers a range of disciplines such as material science, biomaterials, and nanomedicine, focusing on the toxicological effects of particles and fibres. The journal serves as a platform for scientific debate and communication among toxicologists and scientists from different fields who work with particle and fibre materials. The main objective of the journal is to deepen our understanding of the physico-chemical properties of particles, their potential for human exposure, and the resulting biological effects. It also addresses regulatory issues related to particle exposure in workplaces and the general environment. Moreover, the journal recognizes that there are various situations where particles can pose a toxicological threat, such as the use of old materials in new applications or the introduction of new materials altogether. By encompassing all these disciplines, Particle and Fibre Toxicology provides a comprehensive source for research in this field.
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