Ng Jack C, Juhasz Albert, Smith Euan, Naidu Ravi
The University of Queensland, National Research Centre for Environmental Toxicology (Entox), Brisbane, Queensland, 4108, Australia,
Environ Sci Pollut Res Int. 2015 Jun;22(12):8802-25. doi: 10.1007/s11356-013-1820-9. Epub 2013 Jun 14.
Bioavailability (BA) determines the potential harm of a contaminant that exerts on the receptor. However, environmental guidelines for site contamination assessment are often set assuming the contaminant is 100 % bioavailable. This conservative approach to assessing site risk may result in the unnecessary and expensive remediation of a contaminated site. The National Environmental Protection Measures in Australia has undergone a statutory 5-year review that recommended that contaminant bioavailability and bioaccessibility (BAC) measures be adopted as part of the contaminated site risk assessment process by the National Environment Protection Council. We undertook a critical review of the current bioavailability and bioaccessibility approaches, methods and their respective limitations. The 'gold' standard to estimate the portion of a contaminant that reaches the system circulatory system (BA) of its receptor is to determine BA in an in vivo system. Various animal models have been utilised for this purpose. Because of animal ethics issues, and the expenses associated with performing in vivo studies, several in vitro methods have been developed to determine BAC as a surrogate model for the estimation of BA. However, few in vitro BAC studies have been calibrated against a reliable animal model, such as immature swine. In this review, we have identified suitable methods for assessing arsenic and lead BAC and proposed a decision tree for the determination of contaminant bioavailability and bioaccessibility for health risk assessment.
生物利用度（BA）决定了污染物对受体产生的潜在危害。然而，场地污染评估的环境准则通常是在假设污染物100%具有生物利用度的情况下制定的。这种评估场地风险的保守方法可能会导致对污染场地进行不必要且昂贵的修复。澳大利亚的《国家环境保护措施》已历经法定的五年审查，审查建议将污染物生物利用度和生物可及性（BAC）测量方法作为国家环境保护委员会污染场地风险评估过程的一部分予以采用。我们对当前的生物利用度和生物可及性方法、手段及其各自的局限性进行了批判性审查。估计污染物到达其受体的体循环系统（BA）部分的“黄金”标准是在体内系统中确定生物利用度。为此已使用了各种动物模型。由于动物伦理问题以及进行体内研究的相关费用，人们已开发出多种体外方法来确定BAC，作为估计生物利用度的替代模型。然而，很少有体外BAC研究针对可靠的动物模型（如未成年猪）进行校准。在本综述中，我们确定了评估砷和铅BAC的合适方法，并提出了一个决策树，用于确定污染物生物利用度和生物可及性以进行健康风险评估。
