RII Track-4: Advanced Techniques for Assessing Toxicity and Chemical Uptake in Plants in Water Reuse Situations

University Of Nevada Las Vegas, Las Vegas NV

Investigators

Abstract

Nontechnical Description Water shortages are becoming more frequent, and this lack of freshwater is expected to increase due to population growth and long-term drought. Alternative water supplies such as treated wastewater or stormwater runoff can help cities meet their drinking water and agricultural water demands with water that is available locally. However, there are some challenges associated with using these alternative water supplies. One is the formation of harmful substances that result from chemical disinfection (disinfection byproducts or DBPs). A second challenge is the uptake of chemicals, including DBPs, into the edible portion of plants when alternative waters are used for agricultural irrigation. The research addresses these two issues that are at the intersection of food, water, and health. The project will 1) assess new bioassays to measure the toxicity of DBPs in the alternative water supplies, and 2) investigate a novel use for laser ablation electrospray ionization mass spectrometry (LAESI-MS) to detect chemicals taken up into plants that were irrigated with treated wastewater or stormwater runoff. Future benefits include rapid and comprehensive bioassays to screen the toxicity of disinfected water and a better understanding of the risks of using alternative water supplies for agriculture. Technical Description Water shortages are a continual concern, and this lack of freshwater is expected to increase due to population growth and long-term drought. Alternative water supplies (i.e., treated wastewater or stormwater) can help cities meet their drinking water and agricultural water demands with locally-sourced water. However, using these alternative water supplies poses some challenges: 1) the formation of toxic and/or carcinogenic disinfection byproducts (DBPs) and 2) the uptake of chemicals, including DBPs, into the edible portion of plants. This project addresses these interrelated challenges and consists of hands-on skill training (i.e., toxicity bioassays, laser ablation electrospray ionization mass spectrometry; LAESI-MS), as well as research studies over two summers at the host institution, George Washington University (GWU). The research involves the intersection of critical issues: food, water, and health. The first project lays the groundwork for developing rapid and comprehensive bioassays to screen the toxicity of disinfected water. Bioassay screening is necessary to cope with the large number of known (500+) and unknown DBPs and to provide a meaningful approach for understanding the toxicity of disinfected water. The second project uses LAESI-MS for direct molecular analysis of living plants. This would be the first use of LAESI-MS to analyze chemical uptake and metabolite transformation in plants irrigated with reclaimed water. This technique could significantly reduce sample preparation time, and it would allow researchers to monitor chemical transformation over the lifecycle of the plant, which is not possible using the standard process (i.e., plant harvesting). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.