Kelley A. Uhlig was awarded $500 by the Chesapeake Potomac Regional Chapter (CPRC) of the Society of Environmental Toxicology and Chemistry (SETAC). This travel award allowed Kelley to present her research at the National SETAC meeting held 1-5 November 2015 in Salt Lake City, Utah.
Kelley's research aims at determining how natural biofilms may influence sorption and leaching of toxic chemicals. Her supervisor is Dr. Rob Hale.
Kelley's poster was entitled "Sorption of persistent organic pollutants to two bio-based polymers, polylactic acid and polyhydroxyalkanoate".
Abstract. Plastic production has grown 620% since 1975, with over 200 million metric tons produced annually. With the lack of cradle-to-grave waste practices, plastic intrusion on the aquatic and terrestrial environments has become a major environmental concern. Plastics are now ubiquitous in aquatic environments, extending from urban areas to polar seas and the ocean floor. Leaching of chemical additives, present in plastics at % by weight levels, is hypothesized to be enhanced as plastics degrade. Microplastics (plastic particles < 5mm) have also become increasingly recognized as an important transporter of persistent organic pollutants. Ingestion of microplastics containing either additives or surface-sorbed chemicals may deliver enhanced toxicant dosages to organisms of all trophic levels. Biofilms rapidly accumulate on submerged surfaces, acting as a barrier that chemicals need to cross. It has been previously demonstrated that the biofilms play an important role in the accumulation and transfer of some contaminants and various studies have investigated the kinetics and sorption of pesticides in natural river biofilms. However, a specific investigation has not been conducted to examine if natural estuarine biofilms influence the sorption and leaching of persistant, bioaccumulative and toxic (PBT) chemicals to and from microplastics. It has also been implied that plastics may preferentially adsorb different contaminants, but the effects of biofilms on this competition have not been evaluated. Furthermore, consumers are beginning to demand eco-friendly plastics, such as polylactic acid (PLA) used as a replacement for non-degradable plastic packaging and agricultural mulch films and polyhydroxyalkanoate (PHA) suggested as a replacement for cosmetic microbeads. These bioplastics are often characterized as biodegradable therefore investigation of their interactions with PBTs in aquatic environments should be performed before wide adoption of these alternative plastics. This study compares the sorption of PBT chemicals to widely used polyethylene (PE) versus alternatives PLA and PHA and evaluates the influence of natural estuarine biofilms on PBT/microplastic partitioning.