We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Assessing microplastics contamination and characteristics in organic soil amendments in the Greater Accra Metropolitan Area of Ghana
Summary
Researchers assessed microplastic contamination in organic soil amendments, including municipal compost and sewage sludge, used in the Greater Accra region of Ghana. They found microplastic concentrations ranging from about 2,000 to over 4,300 particles per kilogram, far exceeding levels in native soil. The study reveals that organic fertilizers, often considered eco-friendly alternatives, can be a significant source of microplastic pollution in agricultural soils.
The study examines the increasing use of organic soil amendments (OSA) due to declining soil fertility and the high cost of synthetic fertilizers, alongside growing concerns about microplastics (MPs) accumulating in soil, which negatively impact soil, crop, and food quality. This research assessed the presence and characteristics of microplastics in Municipal Solid Waste Composts (MSWC) and dry sewage sludge (DSS) within the Greater Accra Metropolitan Area (GAMA) of Ghana. The study analyzed two sources of MSWC (MSWC 1 and MSWC 2) and two sources of DSS (Sludge 1 and Sludge 2), with five samples each, for microplastic concentrations. A reference soil sample, collected from a depth of 0-25 cm, was also tested. The microplastics were extracted using acid digestion (30 % H2O2 at 70 °C), density separation with a ZnCl2 solution, and vacuum filtration. Results revealed that Sludge 1 had the highest concentration of microplastics (4316 ± 968 MP kg-1), followed by MSWC 1 (3572 ± 1196 MP kg-1), MSWC 2 (3104 ± 418 MP kg-1), and Sludge 2 (2024 ± 562 MP kg-1). The soil sample had the lowest concentration of 232 ± 62 MP kg-1. Statistical analyses (Kruskal Wallis and Dunn's multiple comparisons) showed significant differences (p < 0.05) in microplastic concentrations among the samples. The composition of microplastic polymers varied among the samples. The soil sample predominantly contained cellophane (91.67 %) and polyvinyl propionate (8.33 %). MSWC 1 contained urethane alkyd (31.11 %), polyethylene (26.67 %), and polyester (20 %), while MSWC 2 had polyethylene (24.10 %), polyester (20.48 %), cellophane (18.07 %), and polypropylene (15.66 %). Sludge 1 was dominated by polyethylene (35.29 %), polypropylene (30.25 %), cellophane (15.13 %), and urethane alkyd (11.76 %), whereas Sludge 2 mainly contained polyester (42.86 %), cellophane (23.21 %), urethane alkyd (21.43 %), and polyethylene (12.50 %). Microplastics were prevalent in the MSWC and sewage sludge which were obtained from the GAMA, with significantly higher concentrations than those in the soil samples. Further research is needed to develop strategies to mitigate microplastic pollution in OSAs to improve soil health.
Sign in to start a discussion.
More Papers Like This
Unveiling the abundance and potential impacts of microplastic contamination in commercial organic fertilizers/compost produced from different solid waste
Researchers analyzed commercial organic fertilizers made from different waste sources and found microplastics in 80% of the samples, with compost from mixed municipal waste containing the highest levels. The estimated amounts of microplastics being introduced into agricultural soils through these fertilizers exceeded previous reports. The study highlights the need for stricter regulations on organic fertilizer quality to prevent microplastic contamination of farmland.
Quantification and identification of microplastics in organic fertilizers: the implication for the manufacture and safe application
Researchers measured microplastic contamination in 23 commercial organic fertilizers, finding widespread presence at levels that could meaningfully contribute to agricultural soil pollution when fertilizers are applied. The results raise concerns about organic fertilizers as an underappreciated pathway for microplastics entering farm soils and the food system.
The potential contribution of microplastic pollution by organic fertilizers in agricultural soils of Bangladesh: quantification, characterization, and risk appraisals
Researchers found an average of 1,530 microplastic particles per kilogram of commercial organic fertilizer in Bangladesh, estimating that annual fertilizer application could introduce up to 1,387 metric tons of microplastics to agricultural soils nationwide.
Microplastic contamination of organic fertilisers applied to agricultural soils
This study examined microplastic contamination in organic fertilizers applied to agricultural soils, finding plastic particles in multiple fertilizer types. Organic fertilizers derived from sewage sludge or compost can introduce microplastics into farmland, potentially contaminating crops and groundwater.
Organic amendments as vectors of micro and macro plastic pollution of terrestrial ecosystems
Researchers analyzed seven types of organic amendments commonly applied to farmland, including sewage sludge, manure, composts, and digestates, for microplastic contamination. They found microplastics in all samples, with sewage sludge containing the highest levels and a wide variety of polymer types. The study demonstrates that organic soil amendments are an important and underappreciated pathway through which both micro and macro plastics enter agricultural soils.