Dietary exposure to N-nitrosamines has recently been assessed by the European Food Safety Authority (EFSA) to result in margins of exposure that are conceived to indicate concern with respect to human health risk. However, evidence from more than half a century of international research shows that N-nitroso compounds (NOC) can also be formed endogenously. In this commentary of the Senate Commission on Food Safety (SKLM) of the German Research Foundation (DFG), the complex metabolic and physiological biokinetics network of nitrate, nitrite and reactive nitrogen species is discussed with emphasis on its influence on endogenous NOC formation. Pioneering approaches to monitor endogenous NOC have been based on steady-state levels of N-nitrosodimethylamine (NDMA) in human blood and on DNA adduct levels in blood cells. Further NOC have not been considered yet to a comparable extent, although their generation from endogenous or exogenous precursors is to be expected. The evidence available to date indicates that endogenous NDMA exposure could exceed dietary exposure by about 2–3 orders of magnitude. These findings require consolidation by refined toxicokinetics and DNA adduct monitoring data to achieve a credible and comprehensive human health risk assessment.

欧洲食品安全局 (EFSA) 最近对 N-亚硝胺的膳食暴露进行了评估，得出了暴露范围，旨在表明对人类健康风险的担忧。然而，半个多世纪的国际研究证据表明，N-亚硝基化合物（NOC）也可以内源形成。在德国研究基金会 (DFG) 参议院食品安全委员会 (SKLM) 的这篇评论中，讨论了硝酸盐、亚硝酸盐和活性氮的复杂代谢和生理生物动力学网络，重点讨论了其对内源性 NOC 形成的影响。监测内源性 NOC 的开创性方法基于人血液中N-亚硝基二甲胺 (NDMA) 的稳态水平和血细胞中 DNA 加合物的水平。尽管预计 NOC 是由内源或外源前体产生，但尚未在可比较的程度上考虑进一步的 NOC。迄今为止的证据表明，内源性 NDMA 暴露量可能比膳食暴露量高出约 2-3 个数量级。这些发现需要通过完善的毒代动力学和 DNA 加合物监测数据进行整合，以实现可靠且全面的人类健康风险评估。