We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Methodology for assessing microplastic quantity in contemporary urban surface deposited sediments
Summary
Scientists tested new ways to measure how much microplastic dust settles on city streets, using Ekaterinburg, Russia as a test case—and found that street dust in just this one residential area contained hundreds of tonnes of tiny plastic particles (specifically polyethylene, a common plastic used in bags and packaging). This matters because that dust can get kicked up into the air we breathe or washed into water supplies, and this study's real total is likely even higher since it only counted the smallest, easiest-to-measure particles. The bigger takeaway: better tools for measuring microplastics in everyday city grime are still being developed, which is a
The aim of this exploratory study is to develop an approach for assessing the microplastic content in an urban area. Urban surface-deposited sediments (USDS) are used as a geoindicator component. Three research design schemes have been proposed for determining the microplastic content in USDS. The first scheme involves manually counting polymer particles identified by Raman spectroscopy. The second scheme is based on FTIR (Fourier-transform infrared) analysis of the floating fraction of the USDS, obtained by treating the sediments with a saturated NaCl solution (120 g/L), with quantitative assessment carried out using standard samples prepared from the identified polymers and the mineral matrix. According to the third scheme, polymers in both the floating fraction and the mineral matrix of the USDS were identified using FTIR. The carbon (C), hydrogen (H), and nitrogen (N) contents were then measured. The content of the identified polymers was assessed on the basis of the C:H ratio in the USDS. The first scheme does not allow reliable identification of polymers. The second scheme did not permit reliable quantitative assessment of polymer content in the USDS. However, a combination of FTIR spectroscopy and elemental analysis of floating fraction subsamples <100 μm, separated using a 120 g/L NaCl solution, enabled the quantity of polyethylene (PE) in the USDS to be determined. The total amount of PE in particle size fraction <100 μm of the USDS a residential urban area, using Ekaterinburg (Russia) as a case study, was estimated to range between 242 and 623 tonnes, average value 352 tonnes (corresponding approximately 1100 mg/kg). The quantity of polymers contained within both the mineral matrix and the floating fraction > 100 μm of contemporary sediments remains unknown; it is evident that the total is higher. This estimate is preliminary and may be refined in future studies.