Using a forensic science approach to minimize environmental contamination and to identify microfibres in marine sediments

Abstract

There is growing evidence of extensive pollution of the environment by microplastic, with microfibres representing a large proportion of the microplastics seen in marine sediments. Since microfibres are ubiquitous in the environment, present in the laboratory air and water, evaluating microplastic pollution is difficult. Incidental contamination is highly likely unless strict control measures are employed. Here we describe methods developed to minimize the amount of incidental post-sampling contamination when quantifying marine microfibre pollution. We show that our protocol, adapted from the field of forensic fibre examination, reduces fibre abundance by 90% and enables the quick screening of fibre populations. These methods therefore allow an accurate estimate of microplastics polluting marine sediments. In a case study from a series of samples collected on a research vessel, we use these methods to highlight the prevalence of microfibres as marine microplastics.

Microplastic Distribution at Different Sediment Depths in an Urban Estuary

“…Most microplastics observed were fibers (87%). This phenomenon has been observed in other sediment analyses (MONAS, 2014;Woodall et al, 2015;Zobkov and Esiukova, 2017). Browne (2015) suggests microplastic fibers found in marine habitats may be derived from sewage as consequence of washing clothes.…”

Frequency of Microplastics in Mesopelagic Fishes from the Northwest Atlantic

“…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.…”

Microplastic in three urban estuaries, China

“…Because of the extensive measurements adopted during the entire process of samples analysis, airborne contamination was successfully prevented in present study. More rigorous precautions generally used in the forensic investigations should be taken in the future research (Woodall et al, 2015). Heterogeneous distributed pattern of microplastics were shown between replicates, ranging from 100.0 n/m 3 to 4100.0 n/m 3 .…”