FATE AND BIOAVAILABILITY OF EMERGING MICROPOLLUTANTS FROM BIOSOLID-AMENDED AGRICULTURAL SOILS

Polycyclic synthetic musk fragrances (SMF) are used extensively in personal care products, detergents, and industrial applications. Because of their resistance to heat, water, and oil, polyfluoroalkyl substances (PFASs) are used in non-stick cookware, stain-resistant fabric, food packaging, paints, fire-fighting foam, and industrial surfactants and emulsifiers.The recent environmental detection of these micropollutants has raised concern because of evidence of environmental persistence, the risk of bioaccumulation, and the potential for toxicity, carcinogenesis and endocrine disruption. One potential environmental pathway of concern is through the agronomic land application of industrial and municipal biosolids. A recent study found biosolid concentrations of SMFs and PFASs to be in the ppm and ppb concentrations respectively, with both compound classes appearing on multiple high priority watch lists. Little is known, however, about the environmental fate of these compounds within the 4 million dry tons of biosolids that are land-applied for their agronomic benefit each year. This project seeks to address the USDA priority and AFRI challenge area of food safety by filling in scientific gaps and quantifying the fate and bioavailability of two high priority classes of micropollutants - SMFs and PFASs - from biosolid-amended agricultural soils. The information gleaned from the proposed study will help us to better assess the potential risk of the land-application of biosolids to ecological and food safety, aid in the development of best management practices of biosolid waste disposal and associated risk management plans based on trade-offs, and address stakeholders who have expressed concerns about biosolid safety.We hypothesize that biosolids will provide a source of SMFs and PFASs where they will be available for plant uptake from the vadose zone, potentially impacting both human food and feedstock safety. To test this hypothesis, we have 3 primary objectives:Objective 1: To quantify the aerobic degradation kinetics of SMFs and PFASs in biosolids and biosolid-amended soils. A batch aerobic microcosm study will be used to test the hypothesis that SMFs and PFASs will persist in soils and biosolids after land-application.Objective 2: To quantify the bioaccessibility of SMFs and PFASs from biosolids by measuring desorption kinetics. A batch desorption study will be used to test the hypothesis that SMFs and PFASs in biosolids will leach from the biosolid matrix into the vadose zone where they will be available for plant uptake.Objective 3: To quantify the bioavailability and potential bioaccumulation of SMFs and PFASs from biosolid-amended soils. Greenhouse and field sampling studies will be used to test the hypothesis that SMFs and PFASs from biosolid-amended soils are available for bioaccumulation in plant roots and tissues where they may potentially enter the food chain.While primarily focused on research, this project will also include extension and educational outreach including: mentoring K-12 students and undergraduate researchers, developing undergraduate and graduate learning modules, outreach to local stakeholders through the Lafayette Science Café series (which is open and advertised to the public) and to a broader audience through the release of a Purdue Extension Bulletin on our findings.