We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Microplastic in Dredged Sediments: From Databases to Strategic Responses
Summary
Researchers reviewed the existing scientific literature on microplastics in dredged sediments and built a publicly available database to improve understanding of contamination patterns. They found that microplastic concentrations were generally highest in the top 15 centimeters of sediment and that current guidelines do not address microplastic risks in dredging operations. The study recommends developing strategic management frameworks for handling microplastic-contaminated sediments during dredging projects.
Microplastics (MPs) accumulate in sediments, yet guidelines for evaluating MP risks in dredged sediments are lacking. The objective of this study was to review existing literature on MPs in sediments to improve fundamental knowledge of MP exposures and develop a publicly available database of MPs in sediments. Twelve percent of the reviewed papers (nine studies) included sediment core samples with MP concentrations generally decreasing with depth, peaking in the top 15 cm. The remaining papers evaluated surficial grab samples (0 to 15 cm depth) from various water bodies with MPs detected in almost every sample. Median MP concentrations (items/kg dry sediment) increased in this order: lakes and reservoirs (184), estuarine (263), Great Lakes nearshore areas and tributaries (290), riverine (410), nearshore marine areas (487), dredge activities (817), and harbors (948). Dredging of recurrent shoaling sediments could be expected to contain MPs at various depths with concentrations influenced by the time elapsed since the last dredging event. These results offer key insights into the presence and variability of MPs in dredged sediments, informing environmental monitoring and risk assessment strategies.
Sign in to start a discussion.
More Papers Like This
Initial survey of microplastics in bottom sediments from United States waterways
Researchers measured microplastic occurrence and abundance in sediments from nine dredged US waterways and two undredged reference sites, providing baseline contamination data relevant to the US Army Corps of Engineers' dredging operations. Microplastics were found in all dredged sediment samples, with higher concentrations in more urbanized areas. This study provides context for assessing risks when dredging contaminated sediments that may redistribute microplastics in waterways.
Initial Survey of Microplastics in Bottom Sediments from United States Waterways
Researchers conducted an initial survey of microplastic abundance, occurrence, and polymer composition in bottom sediments from nine dredged US waterways and two reference areas, finding particle counts ranging from 162 to 6,110 particles per kilogram dry weight.
Global mapping for the occurrence of all-sized microplastics in seafloor sediments
Researchers compiled global seafloor microplastic data from 155 marine sediment samples including detailed sampling metadata and abundance measurements for 20 microplastic categories, providing foundational data for understanding the distribution and uncertainty of microplastic contamination on the seafloor.
Microplastics in the Dredged Soil
Researchers (in Japan) developed a standardized method for detecting microplastics in dredged marine sediment and applied it to samples from harbors across Japan. This is the first comprehensive nationwide survey of microplastics in harbor dredge spoils, revealing widespread contamination that raises concerns about where this material is disposed.
Microplastics in sediments: A review of techniques, occurrence and effects
This review examined techniques, occurrence data, and ecological effects of microplastics in sediments, synthesizing evidence that sediments act as a major long-term repository for microplastic contamination in both freshwater and marine systems.