Exposure Assessment of Emerging and Fugitive Contaminants: Rapid Screening of Plant Uptake and Translocation

<p>Increased production and use of man-made chemicals have benefited development, and, human welfare greatly, including unprecedented food production and increasing world-wide standard of living. However the benefit gained has the unintended consequence of increasing ubiquity and diversity of emerging compounds in our biosphere. Society is shortening the water cycle via water reuse and reclamation while advancements in organic molecule design, such as advanced pharmaceuticals and industrial compounds, introduce new potential contaminants at an ever-increasing pace. This proposal describes a high throughput screening, tiered approach to efficiently assess plant uptake and translocation of emerging and fugitive compounds. Understanding the uptake and distribution from a physicochemical perspective will advance knowledge of emerging and fugitive compound fate in plant systems.</p>

<p>To achieve the goal of high throughput screening, in silico (using computers) tools will be developed to predict plant uptake from physicochemical properties. In silico predictions will be validated using agronomic plants subjected to specific emerging and fugitive compounds spanning a broad chemical space. To advance knowledge of transport through the plant vascular systems after uptake, poly-parameter linear free energy relationships will be developed to predict fate of the diverse emerging and fugitive compounds in plant tissues (e.g., lignin). From individual poly-parameter linear free energy relationships, a composite partitioning model will be developed to better elucidate distribution within vascular plants, and to offer insight to emerging and fugitive compound fate in food compartments such as edible stalks, fruits and grains. Fundamental knowledge will advance in several ways. First, single-parameter prediction of emerging and fugitive compound uptake are inaccurate for polar compounds, as chemical space covers multiple dimension. 5-dimensional partitioning poly-parameter linear free energy relationships will be parameterized using high quality data. Second, the in silico predictive tools integrate fundamental chemical and biological understanding, beyond single-parameter relationships or generic box models. Third, a standardized approach to predict and measure emerging and fugitive compounds translocation by plants will increase the value of future research. The tiered approach combines multidisciplinary knowledge to generate a holistic picture of chemical transport and fate in vascular plants, particularly relating to food. Increasing knowledge on organic molecule uptake and translocation in plants will widely impact science and engineering disciplines, including: a) predicting crop uptake of pollutants from irrigation waters, b) though phytoremediation to remove contaminants from the subsurface, and, c) guiding the use of plants as biosensors of subsurface contamination in phyto-forensics. All three approaches protect human health. Agrochemical development and fundamental plant biology will also benefit from the advanced tools to understand and predict organic molecule transport, including plant hormones and community signaling. Given recent breakthroughs that elucidate similarities in transmembrane transport in roots to mammalian intestinal membranes and the blood-brain barrier, the long term merit could be tremendous to many fields. The proposed platform forecasts transport of proposed compounds, many destined to be future emerging and fugitive compounds. Broadly stated, knowledge resulting from this endeavor will address critical societal and health issues, many related to water-food interactions. Society needs to be more proactive to protect human health as human interactions shorten the water cycle, potentially funneling contaminants into and potentially up the food chain. The findings will be incorporated into numerous outreach efforts with a variety of hands-on demos and media-based examples that appeal to multiple levels of education and a variety of citizenry. All efforts rely on familiarity of plants to convey larger messages of health and pollutant impacts. This work directly translates to education platforms and can benefit both contamination assessments and safety of urban gardening in blighted urban areas, where increased exposure potential exists. Overall, society needs better knowledge on pollutant entry to global food supplies to avoid instances where widespread chemical use results in global distribution decades before a pollutant is noted as emerging.</p>