Advancing Exposure Assessment for Food Contaminants Through Implementation of Probabilistic Modeling

Risk assessments for foods, ingredients and additives have evolved over the past few decades to incorporate new techniques such as benchmark dose modeling, and to further develop the utility of tools such as the threshold of toxicological concern, and even to explore advancements in carcinogen risk assessment. However, exposure assessments still tend to rely on deterministic approaches utilizing conservative inputs. Deterministic assessments are easy to conduct and easy to interpret; however, as point estimates of exposure, they do not account for variability in the level and/or likelihood of occurrence of a chemical or population differences in exposure inputs. Probabilistic assessments can further refine deterministic assessments using distributions for various exposure inputs and, as such, better account for exposure uncertainty. This project will survey the current state of adoption of probabilistic exposure modeling by regulatory agencies to inform risk management decisions and regulations for food contaminants, develop criteria for determining high quality distributions for input variables, and highlight the value of further integration of probabilistic exposure assessments into regulatory frameworks, including a discussion of factors that hinder widespread adoption.

Institution: Risk Science International

Principal Investigators: Greg Paoli, Principal Risk Scientist

Amount of Award: $67,500

Year Awarded: 2021

This work is supported by the IAFNS Food and Chemical Safety Committee.

Development of a Research Framework for Evidence-Based Assessment of Potential Carcinogens in Human Diets

Risk assessment of chemicals that are potentially carcinogenic in humans often relies on extrapolation from carcinogenicity bioassays. There is a growing belief in the scientific community that evidence-based risk assessment can replace historical, over-protective guidance-based approaches. However, there is no consensus within the scientific community on an approach or framework for the application of an evidence-based risk assessment. This project will develop such an approach by, first, categorizing potential exposure and mode of action scenarios leading to a carcinogenic response, followed by development of a framework based on sectoral examples such as hepatically activated electrophiles that are potential genotoxic carcinogens.

Institution: Cardno ChemRisk
Principal Investigator: Andrew Maier, PhD, DABT
Amount: $130,000
Year Awarded: 2020

This project is supported by the IAFNS Food and Chemical Safety Committee.

Updating the Metal Dietary Exposure Screening Tool

The IAFNS Food and Chemical Safety Committee invests in the training and education of future scientists and leaders in the fields of food and chemical safety and food toxicology by supporting a Summer Fellowship Program for doctoral students. This project focuses on updating the Metal Dietary Exposure Screening Tool.

Detection of heavy metals at trace levels in foods and food ingredients is common given the unavoidable presence of metals in nature coupled with advancement in analytical methods and lower detection limits. In 2015, the Heavy Metal Subcommittee of the IAFNS Food and Chemical Safety Committee sponsored the development of a Metal Dietary Exposure Screening Tool and publication of the paper titled “Partitioning of Dietary Metal Intake—A Metal Dietary Exposure Screening Tool”. The tool provides a screening-level approach that serves as a first step in a tiered risk assessment process to evaluate potential public health risks when confronted with the detection of select heavy metals in foods and food ingredients. IAFNS and the Joint Institute for Food Safety and Applied Nutrition (JIFSAN) have agreed to collaborate on the continued development and biennial updating of the Metal Dietary Exposure Screening tool.

Institution: University of Rochester
Summer Fellow: Candace Wong, PhD Candidate
Amount Awarded: Summer fellows receive a stipend intended to cover living expenses and transportation to/from Washington, DC.
Year Awarded: 2019

Access the Metal Dietary Exposure Screening Tool.

Learn more about the IAFNS Food and Chemical Safety Committee.

Assessing Human Health Impacts of Global Adoption of Codex Deoxynivalenol (DON) Guidelines

Due to climate change, there has been an increase in occurrence of mycotoxins in food and food ingredients. Multiple strategies have been developed to reduce mycotoxin risks before harvest (in the field), after harvest (in storage, transportation, or processing), and in diets. Developed nations have stricter limits for mycotoxins as compared to developing nations. Strict mycotoxin standards mean that developing nations will export their best quality foods and keep more heavily contaminated foods for domestic consumption, resulting in higher mycotoxin exposure in developing countries. Using Deoxynivalenol (DON, vomitoxin) as a case study, this research project will shed light on the potential human health impacts of the new Codex DON regulations on wheat trade worldwide.

Institution: Michigan State University
Principal Investigator: Felicia Wu, PhD
Amount Awarded: $50,000
Year Awarded: 2018

Read more: Risk Assessment of Dietary Deoxynivalenol Exposure in Wheat Products Worldwide: Are New Codex DON Guidelines Adequately Protective?

Learn more about the IAFNS Food and Chemical Safety Committee.

Evaluation of the Dose-Response for Peanut Allergen

Due to the potentially severe nature of the response and absence of approved treatments, allergic individuals have been advised to avoid the food of concern, and food allergens must be included in the ingredients lists of packaged food. However, with statements such as "may contain allergen X" or "also packaged in a facility that contains allergen Y," it is difficult for consumers, food manufacturers and public health authorities to understand and manage the potential risk of exposures in the food supply. The 2016 National Academy of Sciences Report on Food Allergies provided a series of recommendations, including that regulatory agencies adopt a risk-based approach to identify threshold-based RfDs (Reference Doses) for food allergens. The aim of this project is to to use available data from controlled clinical trials of peanut allergen to conduct a risk-based dose-response analysis to enable establishment of RfDs for peanut allergen.

Institution: University of Cincinnati
Principal Investigator: Lynne Haber, PhD
Total Project Cost: $200,000
Year Awarded: 2017

View this project on the Center for Open Science's Open Science Framework.

Learn more about the IAFNS Food and Chemical Safety Committee.

Evaluating the Applicability of Read-Across Tools and High-Throughput Screening Data for Food Relevant Chemicals

The IAFNS Food and Chemical Safety Committee invests in the training and education of future scientists and leaders in the fields of food and chemical safety and food toxicology by supporting a Summer Fellowship Program for doctoral students. This project focused on Evaluating the Applicability of Read-Across Tools and High-Throughput Screening Data for Food Relevant Chemicals.

Institution: University of Wisconsin Madison
Summer Fellow: Jalissa Wynder, PhD
Amount Awarded: Summer fellows receive a stipend intended to cover living expenses and transportation to/from Washington, DC.
Year Awarded: 2017

Learn more about the IAFNS Food and Chemical Safety Committee.

Comparison and Analysis of Toxcast Data with In Vivo Data for Food-Relevant Compounds Using The Risk21 Approach

The IAFNS Food and Chemical Safety Committee invests in the training and education of future scientists and leaders in the fields of food and chemical safety and food toxicology by supporting a Summer Fellowship Program for doctoral students. This project focused on Comparison and Analysis of Toxcast Data with In Vivo Data for Food-Relevant Compounds Using The Risk21 Approach.

Institution: Michigan State University
Summer Fellow: Alex Turley, PhD
Amount Awarded: Summer fellows receive a stipend intended to cover living expenses and transportation to/from Washington, DC.
Year Awarded: 2016

Read more: Incorporating New Approach Methodologies in Toxicity Testing and Exposure Assessment for Tiered Risk Assessment Using the RISK21 Approach: Case Studies on Food Contact Chemicals

Learn more about the IAFNS Food and Chemical Safety Committee.

Evaluation of Arsenic-Induced Intracytoplasmic Inclusions

Intracytoplasmic inclusions have been observed in various cell types in individuals exposed to high levels of inorganic arsenic in the drinking water or diet and have been classified as micronuclei. However, in our laboratory, we have observed identical types of inclusions in mice exposed to arsenicals and in patients treated with arsenic trioxide for promyelocytic leukemia, and have conclusively demonstrated that these are not micronuclei using electron microscopy and staining with DAPI, a chromosome specific stain. Similar to what has been reported in the literature as micronuclei in the epidemiology studies, the inclusions we observed stain positive with Giemsa, but this is a very non-specific stain. The purpose of this study is to obtain cells from individuals in epidemiology studies that have been exposed to high levels of inorganic arsenic in the drinking water and/or diet and to examine them in detail to determine whether they represent true micronuclei or if they are what we have identified as intracytoplasmic inclusions.

Institution: University of Nebraska Medical Center
Principal Investigator: Samuel Cohen, PhD
Amount Awarded: $28,009
Years Awarded: 2014

Learn more about the IAFNS Food and Chemical Safety Committee.

Evaluating the Association between Dietary Exposure to Inorganic Arsenic on Health Outcomes for the US Population

Chronic adverse health effects have been observed with exposure to high levels of inorganic arsenic. The health effects related to lower levels inorganic arsenic exposure have not been established. The aim of this study is to evaluate longitudinal cohort studies for their utility in estimating dietary
inorganic arsenic exposure and quantifying statistically reliable associations with health outcomes.

Institution: Exponent
Principal Investigator: Joyce Tsuji, PhD, DABT
Amount Awarded: $22,000
Year Awarded: 2014

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An Approach to Standardize the Concepts of Low Dose and Nonmonotonic Dose Response in Toxicological Research and Regulatory Science

The IAFNS Food and Chemical Safety Committee invests in the training and education of future scientists and leaders in the fields of food and chemical safety and food toxicology by supporting a Summer Fellowship Program for doctoral students. This project focused on An Approach to Standardize the Concepts of Low Dose and Nonmonotonic Dose Response in Toxicological Research and Regulatory Science.

Institution: New York University
Summer Fellow: Joshua Vaughan, PhD
Amount Awarded: Summer fellows receive a stipend intended to cover living expenses and transportation to/from Washington, DC.
Year Awarded: 2014

Learn more about the IAFNS Food and Chemical Safety Committee.