Location: Food Animal Metabolism Research
Project Number: 3060-32420-003-000-D
Project Type: In-House Appropriated
Start Date: Jan 5, 2021
End Date: Jan 4, 2026
Objective:
Objective 1: Determine the absorption, distribution, metabolism, and excretion of emerging and legacy chemicals in food animals.
Sub-objective 1.A: Determine the metabolism and disposition of [14C]-nitrofurazone in broiler chickens.
Sub-objective 1.B: Determine the ADME of [14C]-PBDEs 47, 99, and 153 in laying turkeys.
Sub-objective 1.C: Determine the ADME of 1,3,7,8-tetrabromo [14C]-dibenzo-p-dioxin in laying hens.
Sub-objective 1.D: Determine the ADME of a defined mix of PFAS, including perfluorohexane sulfonic acid (PFHxS) in lactating cattle.
Sub-objective 1.E: Determine the fate of PFAS originating in a contaminated water source during the life cycle of laying hens.
Sub-objective 1.F: Determine the ADME of [14C]-(-)-trans-'9-tetrahydrocannabinol (THC) and/or [14C]-cannabidiol (CBD) in lactating dairy goats.
Sub-objective 1.G: Determine the accumulation and depuration kinetics of THC and CBD in feedlot cattle supplemented with dietary hemp.
Sub-objective 1.H: Evaluation of cellular uptake, translocation, and toxicity of microplastics using cell models.
Sub-objective 1.I: Determination of the fate of microplastics in laying hens.
Sub-objective 1.J: Determination of the uptake and depuration of microplastics in lactating dairy goats.
Objective 2: Develop and validate sensitive and accurate rapid analytical tools to detect emerging and legacy residues in food animals and food animal systems.
Sub-objective 2.A: Develop ambient ionization mass spectrometric detection and quantitation techniques of chemicals in matrices easily collected from live animals (blood, hair, urine, saliva).
Sub-objective 2.B: Develop ambient ionization mass spectrometric detection and quantitation techniques of chemicals in postmortem matrices (blood, tissues).
Objective 3: Determine levels and sources of emerging and legacy chemical or biological residues in the domestic food supply.
Sub-objective 3.A: In cooperation with regulatory agencies, determine the levels of dioxins, furans, and PBDEs in the U.S. meat supply.
Sub-objective 3.B: Determine the source(s) contributing to high background levels of PBDEs in commercial turkey.
Approach:
Consumers loathe the idea of chemical residues in milk, meat, and eggs even though quantifiable risk of harm from chemicals in U.S. livestock products is exceedingly low. Regardless, consumers equate trace-levels of chemical residues in food with poor product quality and safety. Consequently, producers, regulatory officials, industry representatives, and consumers agree that chemical residues in food should be minimized to the greatest extent possible.
We propose to conduct absorption, distribution, metabolism, and excretion (ADME) studies on legacy and emerging chemicals for which significant data gaps exist. These chemicals include hemp-derived cannabinoids, a legacy antibiotic (nitrofurazone), halogenated persistent pollutants, and environmentally relevant microplastic contaminants (Objective 1). Basic ADME studies will allow the science-based selection of target matrices (saliva, urine, milk, liver, kidney, fat, etc.) and ‘marker compounds’ (parent compound or metabolites) of critical importance to the development of practical rapid screening technologies (Objective 2). ADME studies also provide data from which pre-harvest residue accumulation rates and post-exposure depuration rates can be calculated. Such data will facilitate the marketing of essentially residue-free animals in instances of known animal exposures. In some cases, especially for highly potent halogenated hydrocarbons and emerging contaminants, the U.S. government has a vested interest in ensuring that residues in remain well below regulatory thresholds. Under Objective 3, we propose a continuation of a 25-year cooperative effort with the USDA Food Safety and Inspection Service (FSIS) to survey the U.S. meat supply for dioxins and dioxin-like chemical residues. This survey has been critical to the discovery of environmental sources of dioxins and has been critical to reducing food animal exposures. We also propose to continue discovery efforts to elucidate contamination sources of livestock-based foods.
Collectively, the goal of this proposal is to develop science-based solutions that minimize consumer exposures to chemical residues in food animal products.
