In its December 9, 2013 issue Chemical and Engineering News reports on how “Plastic pollution harms marine life”. In her article, Deidre Lockwood discusses findings from two recently published peer-reviewed scientific studies looking at fish and lugworms exposed to microplastics enriched with persistent organic pollutants (POPs). In the first study, scientists from University of California at Davis, U.S. fed Japanese medaka fish with microplastic fragments containing POPs at realistic environmental concentrations, as well as virgin microplastic material (Rochman et al. 2013). Compared to the unexposed control group, both plastic-fed groups of fish showed stress-induced changes to the liver. The group exposed to enriched microplastics additionally had statistically significantly higher levels of polybrominated diphenyl ether flame retardants (PBDEs). Polyaromatic hydrocarbons (PAHs) and polychrlorinated biphenyls (PCBs) were also elevated in this group, albeit the finding was not statistically significant.
In the second study, scientists from University of California at Santa Barbara, Exeter University, UK and other institutes exposed the sediment-dwelling lugworm to plastics contaminated with additional chemicals including nonylphenol and triclosan (Browne et al. 2013). Like the fish, the invertebrates showed increased body burdens of plastic additives and contaminants following plastics exposure.
These findings confirm previous concerns that aquatic plastic pollution can affect chemical contamination of the food chain. Microplastics accumulate POPs like PBDEs, PAHs and PCBs and transfer these compounds into animal fatty tissue. Once present in fat tissue, enrichment across the food chain occurs. The tiny plastics fragments are however also an original source of chemical contamination when their additives or monomers are enriched in plastics-ingesting animals. Both studies are among the first to clearly demonstrate that microplastics contaminants are enriched in the food chain, and therefore a serious concern both for environmental and human health.
Plastic pollution harms marine life by Deidre Lockwood. Chemical & Engineering News, 9 December 2013
Rochman, et al. (2013) “Ingested plastic transfers hazardous chemicals to fish and induces hepatic stress.” Nature Scientific Reports 3.
Browne et al. (2013) “Microplastic Moves Pollutants and Additives to Worms, Reducing Functions Linked to Health and Biodiversity.” Current Biology 23(23): 2388-2392.