LB 2-8 - CANCELLED - Rapid monitoring of microplastics in 133 Iowa lakes in relation to recreational activities and land use.

The global annual plastic production rate is approaching 400 million metric tons, and every year significant portion ends up in the aquatic environment. While there have been numerous studies conducted to monitor plastic litter in marine environments, freshwater monitoring is lagging, especially for microplastics (MPs). MPs are plastic particles between 100 nm and 5 mm in length/diameter. Their ubiquitous presence, coupled with the small size, is of potential concern, especially, since the effects of MPs on aquatic ecosystems are not well understood .The objectives of the present research is to develop the first rapid monitoring of MPs in lakes and correlate MPs concentrations with abiotic, biotic, and anthropogenic factors such as recreational activities, land use, lake morphometry, and zooplankton biomass. Fully automated custom-built Bruker LUMOS-II Fourier-transform infrared spectro-microscope was used to identify MPs from water column samples. MPs and zooplankton samples were collected with Wisconsin nets with a mesh size of 63 µm. Samples were collected three times during summer of 2021 from 133 Iowa lakes. Average concentration of MPs across all lakes was 5.2 particles/L (range 0.1-95.5 particles/L). Level of the contamination of the field blanks was 0.1 particles/L. Average dimensions of MPs were 139 µm in length and 77 µm in width. Three most common MPs types were polyvinyl chloride, polyester, and polyethylene representing 46, 30, and 11 %, respectively. Pending statistical analysis will reveal any potential interplay in a multivariate environment.