Sagai Masaru
Tsukuba Institute for Healthy Life (Former Head of Research Team on Health Effects of Air Pollutants in National Institute for Environmental Studies, NIES).
Nihon Eiseigaku Zasshi. 2019;74(0). doi: 10.1265/jjh.19004.
Recently, the main air pollutant has been fine particulate matter (PM), which is taken up by the whole body with severe adverse health effects. The main chemical components of PM are salts of sulfate (and nitrate) and carbons. However, it remains unknown which components are toxic. Here, the author reviewed the literatures to determine which components are toxic and the main mechanisms underlying their toxicity. Many epidemiological studies have shown that sulfate concentration is strongly related to mortality. However, there is no experimental evidence showing that sulfate at environmental concentrations of PM causes cardiovascular disease or other disease. On the other hand, carbon components such as elementary carbon (EC) produces high concentrations of reactive oxygen species (ROS) via its phagocytosis by macrophages, and organic carbon (OC) also produces high concentrations of ROS during its metabolic processes, and the ROS cause acute and chronic inflammation. They cause many diseases including cardiovascular disease, asthma and cancer. Furthermore, there are many lines of evidence showing that epigenetic changes such as DNA methylation or microRNA expression induced by particulate matters also induce the development of many diseases such as those mentioned above. It has been reported that carbon components are incorporated into the brain and produce ROS, and that the ROS cause damage to brain cells and Alzheimer's disease and cognitive disorders in the elderly.From these lines of evidence, the author would like to emphasize that the main toxicity of PM is due to carbon components, and it is important to take countermeasures to decrease the concentration of carbon components in ambient air.
最近，主要的空气污染物一直是细颗粒物（PM），它会被全身吸收并对健康产生严重的不良影响。PM的主要化学成分是硫酸盐（和硝酸盐）盐类以及碳。然而，哪些成分具有毒性仍然未知。在此，作者回顾了相关文献，以确定哪些成分具有毒性以及其毒性的主要潜在机制。许多流行病学研究表明，硫酸盐浓度与死亡率密切相关。然而，没有实验证据表明环境浓度的PM中的硫酸盐会导致心血管疾病或其他疾病。另一方面，诸如元素碳（EC）等碳成分通过被巨噬细胞吞噬会产生高浓度的活性氧（ROS），有机碳（OC）在其代谢过程中也会产生高浓度的ROS，而这些ROS会引发急性和慢性炎症。它们会引发包括心血管疾病、哮喘和癌症在内的多种疾病。此外，有许多证据表明，颗粒物诱导的DNA甲基化或微小RNA表达等表观遗传变化也会诱发上述多种疾病的发生。据报道，碳成分会进入大脑并产生ROS，而这些ROS会损害脑细胞，并导致老年人患阿尔茨海默病和认知障碍。基于这些证据，作者想强调的是，PM的主要毒性归因于碳成分，采取对策降低环境空气中碳成分的浓度非常重要。
