Measuring Microplastics in the Middle Rio Grande Through Albuquerque, New Mexico

The vast production of plastics has resulted in an increase of microplastics (MPs) in the environment. MPs are found in water and food systems, and we demonstrate that MPs are present in the Rio Grande near Albuquerque. In this project, we collected samples from four sites on the Rio Grande in Albuquerque. At each site, we collected water and sediment samples in non-plastic containers to reduce the risk of cross-contamination. Density separation methods were used to float MPs and separate the MPs from sediment, and the MPs were decanted into a vacuum filter. Our procedure for sediment sample processing did not produce reasonable results, therefore these samples were not analyzed or assessed. MPs were manually picked from water sample filter paper using microscopes and tweezers. The primary finding of this project indicates that MPs are present in the Rio Grande. At the upstream site we observed 20 MPs/L, at the first intermediate site there were 19 MPs/L, at the second intermediate site 14 MPs/L were found, and at the site downstream from Albuquerque's water treatment plant 32 MPs/L were found. Although MPs were identified in the Rio Grande and an increase in MPs down river through Albuquerque was observed, we consider these results to be preliminary. Significant uncertainty and variability in our processing approaches exist, therefore additional samples should be collected to verify the results.