Microplastics in lowland Irish karst aquifers

Microplastics have been reported in various environments worldwide. Many studies have documented the occurrence of microplastic particles in the different bodies of water such as oceans, estuaries, and freshwater bodies. Nevertheless, investigations of microplastic contamination of groundwater are still extremely rare since microplastics presence in aquifers has been confirmed only in recent years. In this study, five karst springs in the West of Ireland have been sampled over five consecutive months for quantification and identification of microplastic particles using Fourier-transform infrared spectroscopy (FTIR). Microplastics concentrations ranged from 8.7 particles per litre up to 46.6 particles per litre. It has been found that most of these particles were fibres, as well as that clear and blue fibres were the most dominant colour-types. In terms of polymer types, polyethylene (PE) fibres were identified as the single most dominant microplastic pollutant, however, some notable concentrations of polypropylene (PP) and polyamide (PA) were also found. The results show a very strong and significant correlation between microplastic particle counts and fluorescent whitening compounds signals (well-known indicators of human wastewater contamination since their origin is mostly from laundry detergents) at several springs, which helps to understand the contribution of household-derived contaminants to this environmental problem.