We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Quantification of microplastics in biowastes including biosolids, compost, and vermicompost destined for land application
AI summary Read the abstract
Researchers measured microplastic concentrations in biosolids, compost, and vermicompost destined for land application in New Zealand, finding contamination across all biowaste types. The study highlights how spreading these materials on farmland introduces microplastics into soil, where they could persist and potentially enter the food chain through crop uptake.
The land application of biowastes, including biosolids and compost, is a significant source of microplastics (MP) to terrestrial environments, yet global data on contamination levels are limited. We determined the concentrations of microplastics in biowastes destined for land application in Aotearoa New Zealand. Microplastics were extracted from biosolids, vermicompost, bulk compost, and bagged compost via wet peroxide oxidation digestion and density separations using a modified sediment-microplastics isolation (SMI) unit. The polymer type of each suspected microplastic was confirmed by micro-Fourier-transform infrared (µ-FTIR) spectroscopy, with a minimum detection size of 18 µm. Microplastic concentrations > 0.48 MP/g were identified in every sample, with the highest average abundances in biosolids (2.71 MP/g) and vermicompost (2.69 MP/g), followed by bulk compost (1.94 MP/g) and bagged compost (1.1 MP/g). Fragments (62.7%) were the most frequently detected microplastic morphotype, followed by films (24.7%), fibers (12.2%), and beads (0.4%). Common polymers detected were polypropylene (37.9%), polyethylene (28.6%), and polymethyl methacrylate (PMMA) (11.7%). Identifiable morphotypes included polyurethane foam sponge fragments, polyethylene terephthalate glitter, and PMMA multicolored films. Biodegradable polymers were identified, and their presence in mature compost suggests that compost facilities were unable to provide optimal conditions to support the complete biodegradation of polymers. Annual microplastic contamination in soils from the application of biowaste amendments is projected to be between 1.10 × 107 to 2.71 × 107 MP/ha. The product origin of most microplastics could not be identified, highlighting the ubiquity of microplastics and the urgent need to reduce plastic at the source to reduce instances of pollution in valuable biowastes.
More Papers Like This
Municipal biosolids and effluent irrigated onto land are significant sources of microplastics to the terrestrial environment in New Zealand
AI summary Read the abstract
Researchers found that the application of municipal biosolids and treated wastewater effluent to agricultural land is a significant source of microplastic contamination in soils. Analysis of biosolids and irrigation water from wastewater treatment plants confirmed that even after treatment, these materials carry substantial microplastic loads onto farm fields. The study highlights a major pathway by which microplastics from household and industrial waste are continuously introduced into agricultural soils.
Microplastic in Australian processed organics: Abundance, characteristics and potential transport to soil ecosystem
AI summary Read the abstract
Researchers analyzed processed organic waste products from 11 facilities across Australia and found microplastics in every sample, with concentrations ranging from 1,500 to 16,000 particles per kilogram. They estimated that billions to trillions of microplastic particles could be transferred to Australian soils annually through the application of compost and biosolids. The findings highlight that recycling organic waste, while beneficial for waste reduction, may inadvertently spread microplastic contamination to agricultural land.
Microplastics and impurities in digestates and compost: A comparative study of waste-derived soil amendments
AI summary Read the abstract
Researchers analyzed five types of compost and digestate from organic waste treatment facilities over three months, finding microplastics in all samples at concentrations comprising 30–65% of total plastic content, with fibers, films, and fragments of polyethylene, polypropylene, and PET being most common — highlighting how even properly managed biowaste streams can introduce plastics into agricultural soils.
Quantification and Characterisation of Microplastics in Organic Waste-Derived Soil Amendments
AI summary Read the abstract
Researchers quantified microplastics in Scottish compost, anaerobic digestate, and biosolids used as soil amendments, finding contamination in all samples at concentrations of 34 to 160 particles per gram. Biosolids contained the highest levels, dominated by high-density fibers likely from textile washing, along with over 20,000 cellulosic microfibers per gram. The findings suggest that applying these organic amendments to agricultural land could introduce substantial quantities of microplastics into soil.
Origin, Distribution, Fate, and Remediation of Microplastics in Biowastes and Biowaste-Amended Soil
AI summary Read the abstract
This review chapter tracks how microplastics enter agricultural soil through land-applied biowastes — manure, compost, crop residues, and biosolids — and how they then become available for uptake by soil organisms and entry into the food chain. Because microplastics adsorb other contaminants and act as vectors for co-pollutants, the authors argue that biowaste land application is a significant but underappreciated pathway for microplastic accumulation in the human food supply.
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.