|Imhof, HK; Laforsch, C; Wiesheu, AC; Schmid, J; Anger, PM; Niessner, R; Ivleva, NP: Pigments and plastic in limnetic ecosystems: A qualitative and quantitative study on microparticles of different size classes, Water Research, 98, 64-74 (2016), online: 10.03.2016, doi:10.1016/j.watres.2016.03.015|
|Stichworte: (micro)plastic, Paint (micro)particles, Subalpine lake, Raman microspectroscopy (RM), Heavy metal, Inductively coupled plasma mass, spectrometry (ICP-MS)|
Recently, macroplastic (>5 mm) and especially microplastic (<5 mm) particles have been reported as emerging contaminants in marine and limnetic ecosystems. Their coloration is gained by the addition of pigments to the polymer blend which is the major component of the respective product. However, color is also a feature of paint and coatings whereby the pigment is the major component. Once abraded from a surface, paint particles may enter the environment via similar pathways as microplastic particles. So far no detailed studies of microplastic particles (pigmented and non-pigmented) as well as paint particles have been performed focusing on very small microparticles (1e50 mm), in either marine or limnetic ecosystems. Using Ramanmicrospectroscopy with a spatial resolution down to 1 mm, we report a remarkable increase in the occurrence of (pigmented) microplastic particles below 500 mm. Among those, most particles were found at a size of ~130 mm in a freshwater ecosystem (subalpine Lake Garda, Italy). Moreover, our qualitative and quantitative analyses revealed that the number of paint microparticles significantly increased below the size range of 50 mmdue to their brittleness (the smallest detected paint particle had a size of 4 mm). Inductively coupled plasmamass spectrometry measurements showed that both colored particles found in nature as well as virgin particles contain a high variety of metals such as cadmium, lead and copper. These additives may elicit adverse effects in biota ingesting these mi- croparticles, thus paints and associated compounds may act as formerly overlooked contaminants in freshwater ecosystems.