Recently, Borm and Driscoll published a commentary discussing grouping of Poorly Soluble particles of Low Toxicity (PSLTs) and the use of rats as an animal model for human hazard assessment of PSLTs (Particle and Fibre Toxicology (2019) 16(1):11). The commentary was based on the scientific opinion of several international experts on these topics. The general conclusion from the authors was a cautious approach towards using chronic inhalation studies in rats for human hazard assessment of PSLTs. This was based on evidence of inhibition of particle clearance leading to overload in the rats after high dose exposure, and a suggested over reactivity of rat lung cancer responses compared to human risk. As a response to the commentary, we here discuss evidence from the scientific literature showing that a) diesel exhaust particles, carbon black nanoparticles and TiO2 nanoparticles have similar carcinogenic potential in rats, and induce lung cancer at air concentrations below the air concentrations that inhibit particle clearance in rats, and b) chronic inhalation studies of diesel exhaust particles are less sensitive than epidemiological studies, leading to higher risk estimates for lung cancer. Thus, evidence suggests that the chronic inhalation study in rats can be used for assessing lung cancer risk insoluble nanomaterials.

中文翻译：

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评论：在大鼠中进行的长期吸入性评估肺癌风险的研究可能比其声誉更好。

最近，Borm和Driscoll发表了一篇评论，讨论低毒性低溶解度（PSLTs）的分组以及使用大鼠作为动物模型评估PSLTs的人类危害性的研究（Particle and Fiber Toxicology（2019）16（1）：11） 。该评论基于几位国际专家对这些话题的科学见解。作者的总体结论是对大鼠进行长期吸入研究以评估PSLT的人类危害性时的谨慎方法。这是基于高剂量暴露后抑制颗粒清除导致大鼠超负荷的证据，以及与人类风险相比，大鼠肺癌反应的过度反应性。作为对评论的回应，我们在这里讨论来自科学文献的证据，这些证据表明：炭黑纳米颗粒和TiO2纳米颗粒在大鼠中具有相似的致癌潜力，并且在空气浓度低于抑制大鼠颗粒清除的空气浓度下会诱发肺癌，并且b）柴油机排气颗粒的长期吸入研究不像流行病学研究那么敏感，从而导致较高的肺癌风险估计值。因此，有证据表明，在大鼠中进行的长期吸入研究可用于评估不具肺癌风险的不溶性纳米材料。