GBF Report - Polystyrene Foam

4 1. Introduction 1.1 Background Polystyrene (PS) foam is widely used, which is why it is found in the environment. A common material used in floating docks, unencapsulated PS foam floats are directly exposed and can fragment into pieces of foam. Large pieces of foam litter from boat docks are sometimes referred to as “icebergs,” and the small fragmented pieces of foam that litter shorelines and waterways have the potential to break down even further into small foam microplastics (plastic pieces <5mm). Many mechanisms that physically and chemically degrade PS foam into microplastics are outlined in this report. This report describes the production and use of PS foam, describing some of the sources of PS foam to the environment. Common types of PS foam include expanded polystyrene (EPS) and extruded polystyrene (XPS). These materials are used in water for dock floatation and contain a range of different chemicals. This report then provides evidence on how PS foam is often reported as one of the most common types of plastic pollution around the world and in the Laurentian Great Lakes. The impacts of PS foam in the environment are wide ranging. PS foam impacts fish and wildlife, navigation, beach aesthetics, and there are potential health concerns from exposure to chemical additives. These PS foam docks, especially when unencapsulated, are a known source of plastic pollution and chemical contaminants to waterways around the world. When PS foam enters habitats, it can be ingested by animals in the wild. Examples of PS effects demonstrated in the laboratory include reduced growth, mortality, oxidative stress, changes to behaviour, and reduced reproductive output. Reducing environmental impacts from dock floats is a known challenge to managers worldwide (ERDC, 2009). The results presented in the main body of the document are brief so as to facilitate quick reference for what is known about the production, fate, and effects of PS foam, and associated chemicals. More detail on the underlying evidence base is provided as a series of annexes. 1.2 Objectives The objectives of the report are: 1. to provide evidence on the relationship between dock floats and plastic pollution; 2. to present on the known fate and effects of PS foam in the environment; 3. to share data on where PS foam pollutes the environment in Georgian Bay and the Great Lakes basin from (1) shoreline cleanups and other citizen science efforts, (2) the Seabin Pilot Project, (3) peer review journal articles and (4) reports; 4. to facilitate evidence-based information on the ecotoxicity of PS by bringing together a number of existing studies; 1.3 Scope The report provides evidence to identify sources, understand environmental fate and determine effects to aquatic species of PS foam. This report shares data from shoreline cleanups and other citizen science efforts, the Seabin Pilot Project, peer review journal articles and other reports. This report also outlines what is known currently about PS foam associated chemicals. The evidence presented here relies on aquatic studies from Georgian Bay, the Great Lakes, St. Lawrence River, and other freshwater and marine studies. “Iceberg”PS foam litter picked up by volunteers in 2019 Examples of the thousands and thousands of fragmented pieces of PS foam on shorelines