Safe environment concentrations under uncertainty

描述(由申请人提供)： 使用包含污染物浓度和其他因素的风险方程来估计环境污染物的风险。由于风险管理的总体目标是确保此类风险不会大到无法容忍的程度，我们需要一些方法来计算从法规或审慎规定的风险限制到污染物的允许环境浓度。现在众所周知，确定性评估中使用的简单倒置风险方程式来计算清理目标的方法在概率评估中不起作用。已经提出了几种方法，但没有一种方法足够普遍。我们已经开发了简单而高效的方法来计算在概率评估的背景下满足多个同时标准的清理目标。该方法可以与多个受体一起使用，并对目标风险的百分位数进行任意多个限制。拟议的研究将探索这一方法的特性，将其扩展到更复杂的问题，涉及多种影响(例如，毒物导致两种疾病)、多种热带水平(例如，浮游生物对贝类对人类的影响)、多种接触途径(例如，呼吸、饮用、皮肤吸收)、多种潜在协同作用的毒物、暴露建议，以及人类健康风险评估的相关领域。将为每个主题领域开发案例研究，以证明该方法的可行性和通过科学文献传播的结果。将开发用户友好的软件，使风险管理专业人员可以使用这些方法。

DESCRIPTION (provided by applicant): The risk from an environmental contaminant is estimated with a risk equation involving the contaminant's concentration and other factors. Because the overall goal of risk management is to ensure such risks are not intolerably large, we need some way to back calculate from constraints on risk mandated by regulation or prudence to the allowable environmental concentration for the contaminant. It is now well known that the approach used in deterministic assessments of simply inverting the risk equation to compute the cleanup goal does not work in a probabilistic assessment. Several approaches have been proposed, but none is sufficiently general. We have developed simple and efficient methods to compute cleanup goals that satisfy multiple simultaneous criteria in the context of a probabilistic assessment. The approach can be used with multiple receptors and with arbitrarily many constraints on percentiles of the target risk. The proposed research will explore the properties of this approach, extend it to more complex problems involving multiple effects (e.g., the toxicant causes two diseases), multiple tropic levels (e.g., plankton to shellfish to humans), multiple exposure pathways (e.g., breathing, drinking, dermal absorption), multiple potentially synergistic toxicants, exposure advisories, and related areas of human health risk assessment. Case studies will be developed for each of these subject areas to demonstrate the workability of the approach and the results disseminated via the scientific literature. User-friendly software will be developed to make these methods available to risk management professionals.