We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
An Overlooked Entry Pathway of Microplastics into Agricultural Soils from Application of Sludge-Based Fertilizers
AI summary Read the abstract
Researchers analyzed sludge-based fertilizers applied to agricultural soils and found high microplastic concentrations (hundreds to thousands per kilogram of dry weight) that were transferred to soils after application, identifying this as an important but overlooked pathway for terrestrial microplastic contamination.
The widespread application of sewage sludge produced from wastewater treatment plants for agricultural use has been regarded as a primary source of microplastics (MPs) into soils. However, little is known regarding MPs in sludge-based fertilizers and their relevant fate in soils as being applied in agriculture. We comprehensively investigated the abundance, polymer size, type, and morphology of MPs in dewatered sludge, sewage sludge composts, sludge-based fertilizer-amended soils, and earthworms by stereoscopy and micro Fourier transform infrared (μ-FTIR) spectrometry methods. The results clearly showed that the quantity of MPs in soils exhibited a close correlation with the application rate of sludge-based fertilizers. The total abundances of MPs were 545.9 and 87.6 items/kg in soils after annual amendment with 30 (field A) and 15 t/ha (field B) of sludge composts, which is significantly higher than that without compost application (field C, 5.0 items/kg). Correspondingly, MPs were found in earthworms with low quantities of 1.8 and 0.4 items/individual in fields A and B, respectively, while no MP was detected in field C. We speculate that sludge composts may act as a vehicle of MPs into soils and then enter soil biota and in turn influence the spread of MPs in the environment.
More Papers Like This
The overlooked pathway: A systematic review on sewage sludge treatment as a critical secondary source of terrestrial micro(nano)plastics
AI summary Read the abstract
This systematic review examines sewage sludge as an overlooked pathway for microplastics to contaminate land, with concentrations reaching over 1,300 particles per kilogram. When this sludge is applied to farmland as fertilizer, aged and chemically modified microplastics enter agricultural soil, where they may be more toxic than fresh particles and can potentially be taken up by crops.
Microplastics in liquid biofertilizers: An overlooked threat to agricultural soil?
AI summary Read the abstract
Researchers quantified microplastic concentrations in liquid biofertilizers and estimated their contribution to agricultural soil loading, finding that fragment-dominated particles in the 5–50 μm range represent a measurable but minor input compared with sewage sludge, though repeated long-term application could cause gradual accumulation.
Evidence of microplastic accumulation in agricultural soils from sewage sludge disposal
AI summary Read the abstract
Agricultural soils from 31 fields with different sludge application histories were analyzed for microplastics, finding significant accumulation in fields with repeated sludge applications and a positive correlation between application frequency and plastic particle counts. The study provides direct field evidence that sewage sludge fertilization is a major pathway for microplastic accumulation in agricultural soil.
Sewage sludge application as a vehicle for microplastics in eastern Spanish agricultural soils
AI summary Read the abstract
Scientists measured microplastics in sewage sludge from Spanish wastewater treatment plants and in agricultural soils receiving sludge applications, finding that sludge application transferred hundreds to thousands of microplastic particles per kilogram into agricultural soil.
Microplastics in Sludges and Soils: A Comprehensive Review on Distribution, Characteristics, and Effects
AI summary Read the abstract
This review summarizes research on microplastics in sewage sludge and soil, noting that when contaminated sludge is used as fertilizer, it turns farmland into a major reservoir for microplastic pollution. The accumulated microplastics can alter soil properties, harm soil organisms, and potentially enter crops and groundwater, creating pathways for human exposure through food and drinking water.
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.