We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Determination of microplastic contamination levels and trends in vast oceanic sediment areas with uncertainty
AI summary Read the abstract
This study developed a Monte Carlo simulation method to distinguish real changes in microplastic contamination from measurement noise and natural heterogeneity in a large offshore area near Portugal. Applied to sediment samples collected over time across a 700 km² zone, the approach successfully identified meaningful contamination trends despite high spatial variability. This statistical tool is valuable for regulators and researchers who need objective evidence of whether ocean microplastic levels are actually worsening.
Small plastic particles, designated as microplastics, are known vehicles of several contaminants desorbed from their surface after being ingested by marine organisms. The monitoring of the levels and trends of microplastics in oceanic areas is essential to identify relevant threats and respective sources whose management should be improved to protect the environmental resources. However, the assessment of contamination trends in large oceanic areas is affected by contamination heterogeneity, sampling representativeness, and the uncertainty of collected sample analyses. Only contamination variations not justifiable by system heterogeneity and their characterisation uncertainty are meaningful and should be taken seriously by the authorities. This work describes a novel methodology for the objective identification of meaningful variation of microplastic contamination in vast oceanic areas by the Monte Carlo simulation of all uncertainty components. This tool was successfully applied to the monitoring of the levels and trends of microplastic contamination in sediments from a 700 km2 oceanic area from 3 km to 20 km offshore Sesimbra and Sines (Portugal). This work allowed concluding that contamination has not varied between 2018 and 2019 (difference of mean total microplastic contamination between -40 kg-1 and 34 kg-1) but that microparticles made of PET are the major type of studied microplastics (in 2019, mean contamination is between 36 kg-1 and 85 kg-1). All assessments were performed for a 99 % confidence level.
More Papers Like This
Bottom-Up Evaluation of the Uncertainty of the Quantification of Microplastics Contamination in Sediment Samples
AI summary Read the abstract
Researchers developed a statistical methodology to quantify measurement uncertainty in microplastic contamination assessments of sediments, using Poisson-lognormal modeling and Monte Carlo methods. Applied to Portuguese inland waters, the approach enables objective comparison of contamination levels across sites.
How many samples do we need to be representative? Grid sampling in Danish waters for assessing the distribution of microplastics and tire wear particles in seabed sediments
AI summary Read the abstract
Researchers conducted grid sampling at two Danish coastal sites to assess microplastic and tire wear particle variability in seabed sediments, finding significant concentration variation within and between sites, no tire wear particles at the more remote Strandby site, and Monte Carlo simulations showing that 10 sampling points give only a 50% probability of estimating the true mean within 94-119%.
Microplastic pollution characteristics in global marine sediments: A meta-analysis.
AI summary Read the abstract
This review combined data from many studies on microplastics in ocean floor sediments worldwide, finding amounts varied widely, with most pieces smaller than 1 millimeter. The analysis found differences in testing methods, rather than location, explained most of the variation between studies, highlighting a need for standardized measurement approaches.
Quantifying microplastic pollution on sandy beaches: the conundrum of large sample variability and spatial heterogeneity
AI summary Read the abstract
This methodological study tested different sampling approaches for measuring microplastic pellets on sandy beaches and found that concentrations vary greatly over small spatial distances, making single samples unreliable. The authors recommend specific multi-sample strategies to get accurate estimates of beach microplastic contamination.
A large-scale investigation of microplastic contamination: Abundance and characteristics of microplastics in European beach sediment
AI summary Read the abstract
This large-scale investigation characterized microplastic contamination across a wide geographic area, documenting abundance and polymer types and providing a baseline dataset for tracking pollution trends over time.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.