The REI index values were 2.4 for PP straws, 6.4 for PLA straws, and 5.1 for PA straws with landfill and 3.2 for PP straws, 6.8 for PLA straws, and 4.9 for PA straws with incineration. The results show that US daily consumption of disposable drinking straws (500 million straws daily) may carry significant environmental burdens regardless of straw types, with the feedstock manufacture stage of the life cycle creating most of the contribution.

Eight environmental impact categories, not including marine litter, were analyzed and a composite relative environmental impact index (REI) was derived for quantitative comparison. This research employs the standard life cycle assessment (LCA) approach to assess and compare the environmental impact of plastic straws made from polypropylene (PP), and its biodegradable alternatives made from polylactic acid (PLA) and paper (PA) in the United States. Sound environmental management to control marine plastic pollution requires a careful assessment of environmental costs and benefits of replacing single-use plastics with their biodegradable counterparts.