Microplastics in Irish Freshwaters: a Preliminary Study

Microplastics in the marine environment have been recognized as an issue of concern in recent decades, leading to a significant body of research in this area, as summarised in recent review articles by by Andrady (2011) and Cole et al. (2014). Microplastics can be categorised as primary or secondary microplastics. Primary microplastics are manufactured with sub-millimeter dimensions and used in cosmetic products such as facial scrubs, in air-blasting processes for rust or paint removal, and as vectors for drug delivery in medicine. Secondary microplastics arise from the breakdown of larger plastic materials and debris, due to physical, chemical and biological processes in the aquatic or terrestrial environment. Microplastics are of concern due to their potential for ingestion and subsequent bioaccumulation by aquatic organisms from plankton to fish, birds and mammals, as well as their potential to release plasticizers and other additives by leaching and due to further breakdown of the microplastic particles (Wagner et al., 2014). Until recently however, there has been relatively little focus on microplastics in freshwater systems (Imhof et al., 2013; Free et al., 2014; Lechner et al., 2014) despite their obvious significance as inputs to the marine environment. To date, no data has been published on the prevalence or characteristics of microplastic pollution in Irish freshwaters. In this study we have validated methods for the detection, characterization and quantification of microplastics in water and sediment samples. Samples were collected from lake and riverine locations and the microplastics content was analyzed using physico-chemical tests and FTIR spectroscopy. Samples from wastewater treatment plants were also collected and analyzed in order to assess the contribution of these plants to microplastic inputs to freshwater systems.