New and improved methods for risk assessment of food and pharmaceutical products safety and for forensic analysis

为了测量固体食品和药品中潜在有害元素（如铅和砷）的浓度，政府机构首先将它们溶解，这涉及多个步骤。这不仅需要时间和苛刻的化学品，而且还增加了污染的可能性（假阳性）或可能导致某些元素的损失（假阴性）。此外，这种方法不提供任何关于每种元素的化学形式的信息，而化学形式决定了毒性。最关键的是，它也没有提供任何关于生物可及性的信息，即在胃肠道中的溶解度。然而，一种毒素只有在进入血液时才会引起安全问题，因为它可能在血液中发挥毒性作用。拟议的研究计划将涉及开发简单的分析方法，以快速确定固体中存在的每种元素的水平。如果一种元素的含量对人类健康构成潜在危险，那么将使用另一种相对快速的分析方法来测量生物可接近的部分。最后，如果生物可及部分含有不同化学形式的元素，将使用另一种方法来区分和量化有毒和毒性较小的形式，以真正评估风险。快速和具有成本效益地获取食品和药品中元素形态和生物可及浓度的信息，将使毒理学研究能够确定不同元素之间是否存在协同作用或拮抗作用。这将使加拿大当局能够将食品和药品中的元素（甚至可能是特定元素形式）的水平控制在安全水平，从而减少其免疫毒理学影响。在一个相关的项目中，将在其他谷物上测试清洗或浸泡食物的效果，以确定何时可以使它们更安全地食用。众所周知，清洗或浸泡食物可以去除大米中的一些有毒砷。将研究烹饪的影响，包括烹饪食物的方式（如煮沸、烘烤、压力烹饪等）对主食（大米、小麦、玉米、面包等）中存在的生物可及部分和化学形式的影响，以确定烹饪是否有有益的影响。在第三个相关项目中，将优化一种快速分析技术，用于区分各种法医样本（头发、肇事逃逸案件中留下的汽车油漆碎片、指甲等），从而为警察机构的武库增加一种新工具，帮助他们破案。包括加拿大皇家骑警在内的执法机构将能够轻松、经济地实施所开发的方法。至少有9名研究生和25名本科生将参与这项研究的不同方面，该研究将使用现代仪器和协议进行，以保证加拿大人的安全。

To measure the concentration of potentially harmful elements such as lead and arsenic in solid food and pharmaceutical products, government agencies first dissolve them, which involves multiple steps. This not only takes time and requires harsh chemicals but also increases the likelihood of contamination (false positive) or may result in the loss of some of the elements (false negative). In addition, this approach does not provide any information on the chemical form of each element, which determines toxicity. Most critically, it also does not provide any information on bio-accessibility, i.e. solubility in the gastrointestinal tract. Yet, a poison is only a safety concern if it enters the blood stream, where it may exert its toxic effect. The proposed research program will involve the development of simple analysis methods that quickly determine the level of each element present in a solid. If the level of an element poses a potential danger to human health, another relatively fast analysis method will then be used to measure the fraction that is bio-accessible. Finally, if the bio-accessible fraction contains different chemical forms of the elements, another method will be used to distinguish and quantify the toxic and less toxic forms to truly assess the risk. Rapid and cost-effective acquisition of information on both element forms and bio-accessible concentrations in foods and pharmaceutical products will enable toxicological studies to establish if a synergistic or antagonistic effect exists between different elements. This will empower Canadian authorities to regulate the levels of elements (and perhaps even specific element forms) in food and pharmaceutical products at safe levels, thereby reducing their immuno-toxicological effects. In a related project, the effect of washing or soaking food, which is known to remove some toxic arsenic from rice, will be tested on other grains to find out when it can make them safer for consumption. The effect of cooking, including the manner in which food is cooked (such as boiling, toasting, pressure cooking, etc.) on the bio-accessible fraction and the chemical forms present in staple food (rice, wheat, corn, bread, etc.) will be studied to establish if cooking has a beneficial effect. In a third related project, a quick analysis technique will be optimized for the discrimination of various forensic samples (head hair, automotive paint fragments left in hit-and-run cases, finger nails, etc.), thereby adding a new tool to the arsenal of police agencies to help them solve crimes. Law enforcement agencies, including the Royal Canadian Mounted Police, will be able to implement the methods developed easily and cost-effectively. At least 9 graduate and 25 undergraduate students will participate in different aspects of this research, which will be carried out using modern instruments and protocols in an attempt to guarantee the safety and security of Canadians.