Assuring quality in microplastic monitoring: About the value of clean-air devices as essentials for verified data

Abstract

Avoiding aerial microfibre contamination of environmental samples is essential for reliable analyses when it comes to the detection of ubiquitous microplastics. Almost all laboratories have contamination problems which are largely unavoidable without investments in clean-air devices. Therefore, our study supplies an approach to assess background microfibre contamination of samples in the laboratory under particle-free air conditions. We tested aerial contamination of samples indoor, in a mobile laboratory, within a laboratory fume hood and on a clean bench with particles filtration during the examining process of a fish. The used clean bench reduced aerial microfibre contamination in our laboratory by 96.5%. This highlights the value of suitable clean-air devices for valid microplastic pollution data. Our results indicate, that pollution levels by microfibres have been overestimated and actual pollution levels may be many times lower. Accordingly, such clean-air devices are recommended for microplastic laboratory applications in future research work to significantly lower error rates.

Frequency of Microplastics in Mesopelagic Fishes from the Northwest Atlantic

“…For future studies we strongly recommend a more thorough cleaning of plastic particles with filtered, ultrapure water. Furthermore, it is interesting to note that despite taking a forensic approach during the extraction of microplastics (Wesch et al, 2017) we noted a large amount of fibres (98%) amongst the sampled microplastics. This is in agreement with other findings (Lusher et al, 2013(Lusher et al, , 2016Neves et al, 2015;Rochman et al, 2015;Bellas et al, 2016).…”

“…The extraction of microplastics and subsequent examination of the filters was performed in compliance with the most recent findings in microplastic contamination prevention methodologies (Woodall et al, 2015;Wesch et al, 2017). All equipment used was pre-rinsed with 0.2 µm filtered MilliQ TM water and all clothing worn during laboratory work was of nonpolymer nature.…”

“…Since then, new and improved methodologies for microplastic extraction have been developed with an emphasis on ultra-clean techniques in order to prevent airborne contamination (Wesch et al, 2017).…”

A temporal sediment record of microplastics in an urban lake, London, UK

“…Discounting the low number found in pre-twentieth-century mud and likely occurrence from modern contamination (Woodall et al 2015;Wesch et al 2017;Willis et al 2017), it may be significant that the few coloured fibres found were red. Fibres of the same colour and form were identified in the upper 50 cm of the core as possibly being made of polysulphide rubber (Table 2).…”

“…This proportion of identified versus unidentified particles is common in aquatic microplastic studies using Raman spectroscopy (identified 41-67%) (Ballent et al 2016;Clunies-Ross et al 2016;Frère et al 2017). Because of the low number and size of microplastics found, and the ubiquity of microfibres found in urban atmospheres, contamination during coring and processing (Woodall et al 2015;Wesch et al 2017) must be acknowledged as a possible source of error. The number of fibres in the blanks examined during processing, and their potential influence on the interpretation of early plastic occurrence, is recognized.…”