Regulatory interest in assessing the health effects of vanadium compounds is hindered by the limited chronic toxicity data available. The National Toxicology Program (NTP) conducted a robust chronic inhalation bioassay of crystalline vanadium pentoxide (V2O5), but this study has noteworthy limitations. Multiple dose range-finding studies were conducted at two separate laboratories that showed cross-laboratory differences in lung pathology (inflammation) in both species and likely complicated dose-selection. In mice, the only tissue pathology (inflammation and tumors) was at the site of entry, the respiratory system. Although significantly different from control, because lung tumor incidences were at a maximal level across all concentrations tested, the ability to extrapolate risks to the public is problematic. In rats, lung inflammation and vanadium lung burdens were comparable to those of mice, but lung tumorigenicity was not substantiated, further raising questions about appropriate species extrapolation. Open questions also exist regarding test material chemical characterization, as the laboratory relied on vanadium measurement in test chambers as a surrogate for V2O5. In sum, the NTP V2O5 study does not provide an appropriate dataset for purposes of classification and risk assessment. Additional repeat exposure studies of vanadium compounds are needed and recommendations for future studies are provided.

中文翻译：

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在风险评估中使用NTP慢性生物测定法对五氧化二钒的局限性。

由于可获得的有限的慢性毒性数据阻碍了评估钒化合物对健康影响的监管兴趣。美国国家毒理学计划（NTP）对五氧化二钒（V2O5）进行了稳健的慢性吸入生物测定，但该研究存在值得注意的局限性。在两个不同的实验室进行了多次剂量范围研究，结果表明这两种物种的肺病理学（炎症）跨实验室差异均存在，而且剂量选择可能很复杂。在小鼠中，唯一的组织病理学（炎症和肿瘤）是在进入部位即呼吸系统。尽管与对照有显着差异，但由于在所有测试浓度下肺肿瘤的发生率均处于最高水平，因此将风险推算给公众的能力存在问题。在大鼠中 肺部炎症和钒肺部负担与小鼠相当，但肺部致瘤性没有得到证实，这进一步引发了有关适当物种外推的问题。关于测试材料化学特性的问题也存在悬而未决的问题，因为实验室依赖于测试室中的钒测量作为V2O5的替代物。总之，NTP V2O5研究没有提供用于分类和风险评估的适当数据集。需要对钒化合物进行其他重复暴露研究，并提供有关未来研究的建议。因为实验室依赖于测试室中的钒测量作为V2O5的替代物。总之，NTP V2O5研究没有提供用于分类和风险评估的适当数据集。需要对钒化合物进行其他重复暴露研究，并提供有关未来研究的建议。因为实验室依赖于测试室中的钒测量作为V2O5的替代物。总之，NTP V2O5研究没有提供用于分类和风险评估的适当数据集。需要对钒化合物进行其他重复暴露研究，并提供有关未来研究的建议。