Presenter: Cara Megill (Hawai'i Pacific University Center for Marine Debris Research)

Description:
Plastic products consist of approximately 93% by mass of plastic polymer and 7% of chemical additives. The number of individual chemical additives used in plastics is staggering and are categorized into a wide range of chemical classes including colorants, light stabilizers, antioxidants, plasticizers, flame retardants, and heat stabilizers.  Many of these chemicals leach out of plastic products into the environment, and can produce a range of toxicities in organisms if exposure exceeds the toxic threshold. Research addressing the environmental exposure of marine organisms to these compounds is lacking. To discover the most impactful data gaps, we compiled a comprehensive database of plastic additive concentrations measured in marine environments separated by four compartments (plastic, water, sediment, biota). Using this database, we performed meta-analyses to summarize the state of the science and begin to answer a myriad of questions. 193 studies have been entered, ranging from 1978 to 2021. Seawater is the compartment that has received the most attention and plastic debris found in the ocean has received the least. A broader diversity of additive classes have been measured in the plastic samples than in the other compartments. Among studies analyzing biological tissues, most focus on brominated flame retardants followed by phthalates, most are from Europe and Asia, and most analyzed marine invertebrates. The database can be mined to assess the selection of sampling and analytical methods used, investigate spatial and temporal trends for a particular chemical, and determine which samples exceed toxicity thresholds.