In their Correspondence in The Lancet Diabetes & Endocrinology, Roy Gerona and colleagues have shown that indirect analytical methods using enzymatic hydrolysis to determine bisphenol A (BPA) metabolites in urine do not provide the same results as direct measurement of the identified metabolites using authentic reference standards. The authors explain that direct and indirect methods allow total BPA (free and conjugated) levels to be determined in urine. After which, like most data published in the field of environmental sciences, exposure is expressed as the amount of this fictional compound, total BPA. Finally, they conclude that indirect techniques requiring deconjugation are flawed and that previous studies using these methods underestimated actual levels of BPA in humans and risks to human health. In our opinion, however, the approach using total BPA as a biomarker of BPA exposure is also flawed. Adding concentrations of BPA to those of BPA glucuronide and BPA sulfate, is like adding apples and oranges, it does not make sense.

中文翻译：

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BPA和风险评估。

在《柳叶刀》糖尿病与内分泌学的通讯中Roy Gerona及其同事表明，使用酶水解法测定尿液中双酚A（BPA）代谢物的间接分析方法所提供的结果与使用真实参考标准物直接测量鉴定出的代谢物的结果不同。作者解释说，直接和间接方法可以测定尿液中的总BPA（游离和结合）水平。然后，就像环境科学领域中发布的大多数数据一样，暴露量表示为该虚构化合物的总量BPA。最后，他们得出结论，要求脱变的间接技术存在缺陷，并且使用这些方法的先前研究低估了人类的BPA实际水平以及对人类健康的风险。但是，我们认为，将总BPA用作BPA暴露生物标志物的方法也存在缺陷。