Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China.
Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China; Synergy Innovation Institute of GDUT, Shantou, 515041, China.
Environ Pollut. 2020 Oct;265(Pt B):115070. doi: 10.1016/j.envpol.2020.115070. Epub 2020 Jun 23.
Particle-bound pollutants can pose a health risk to humans. Inhalation exposure evaluated by total contaminant concentrations significantly overestimates the potential risk. To assess the risk more accurately, bioavailability, which is the fraction that enters into the systemic circulation, should be considered. Researchers have replaced bioavailability by bioaccessibility due to the rapid and cost-efficient measurement for the latter, especially for assessment by oral ingestion. However, contaminants in particulates have different behavior when inhaled than when orally ingested. Some of the contaminants are exhaled along with exhalation, and others are deposited in the lung with the particulates. In addition, a fraction of the contaminants is released into the lung fluid and absorbed by the lung, and another fraction enters systemic circulation under the action of cell phagocytosis on particulates. Even if the release fraction, i.e., release bioaccessibility, is considered, the measurement faces many challenges. The present study highlights the factors influencing release bioaccessibility and the incorporation of inhalation bioaccessibility into the risk assessment of inhaled contaminants. Currently, there are three types of extraction techniques for simulated human lung fluids, including simple chemical solutions, sequential extraction techniques, and physiologically based techniques. The last technique generally uses three kinds of solution: Gamble's solution, Hatch's solution, and artificial lysosomal fluid, which are the most widely used physiologically based simulated human lung fluids. External factors such as simulated lung fluid composition, pH, extraction time, and sorption sinks can affect release bioaccessibility, whereas particle size and contaminant properties are important internal factors. Overall, release bioaccessibility is less used than bioaccessibility considering the deposition fraction when assessing the risk of contaminants in inhaled particulates. The release bioaccessibility measurement poses two main challenges: developing a unified, accurate, stable, simple, and systematic biologically based method, and validating the method through in-vivo assays.
颗粒物结合态污染物会对人体健康造成危害。采用总污染物浓度进行吸入暴露评估会显著高估潜在风险。为了更准确地评估风险，应考虑生物利用率，即进入体循环的部分。由于后者（生物可给性）的测量快速且经济高效，研究人员用其替代了生物利用率，尤其是在口服摄入评估方面。然而，颗粒物中的污染物在吸入时的行为与口服摄入时不同。部分污染物随呼气排出，其余部分则与颗粒物一起沉积在肺部。此外，部分污染物会释放到肺部液体中并被肺部吸收，还有一部分在颗粒物被细胞吞噬作用下进入体循环。即使考虑了释放部分（即释放生物可给性），测量仍面临诸多挑战。本研究强调了影响释放生物可给性的因素，并将吸入生物可给性纳入吸入污染物风险评估中。目前，模拟人体肺液有三种提取技术，包括简单的化学溶液、顺序提取技术和基于生理的技术。最后一种技术通常使用三种溶液：Gamble 溶液、Hatch 溶液和人工溶酶体液，它们是最广泛使用的基于生理的模拟人体肺液。模拟肺液组成、pH 值、提取时间和吸附阱等外部因素会影响释放生物可给性，而粒径和污染物特性是重要的内部因素。总体而言，在评估吸入颗粒物中污染物的风险时，考虑到沉积部分，释放生物可给性的使用不如生物可给性广泛。释放生物可给性测量面临两个主要挑战：开发一种统一、准确、稳定、简单和系统的基于生物学的方法，并通过体内试验验证该方法。
