An outdoor mesocosm experiment was done to realistically assess the
effects of three different types of microplastic pollution (one biodegradable type; polylactic acid and two
conventional types; polyethylene and polyvinylchloride) at increasing concentrations (0.02, 0.2 and 2% of
wet sediment weight) on the health and biological activity of lugworms, Arenicola marina (Linnaeus,
1758), and on nitrogen cycling and primary productivity of the sediment they inhabit.