We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
AQuantitative Environmental Risk Assessment for Microplasticsin Sewage Sludge Applied to Land
Summary
Researchers combined exposure data with species sensitivity distributions to conduct the first quantitative ecological risk assessment of microplastics in sewage sludge-amended soils. Results indicated that current sludge application rates pose a chronic risk to certain soil invertebrates, particularly at sites receiving repeated applications.
The application of sewage sludge to land delivers high levels of microplastics (MPs), contributing to soil contamination and chronic effects on soil biota. Despite this, the quantitative chronic risk assessment of MPs in sludge-amended soils (SAS) to soil biota has not been thoroughly addressed, and none has been done directly on sludge samples. Here, we combined environmental exposure and species sensitivity distributions, built on published data, with two-dimensional Monte Carlo simulations to characterize the risk from MPs in sludge samples and in SAS, testing worst-case and realistic case scenarios of sludge behavior in soil. Contamination with MPs frequently exceeded the concentration likely to affect more than 5% of the species. Risk characterization showed that the worst-case MP scenario affects 39% of species, while the realistic scenario affects 15–18% of soil species, implying that the current state of sludge application fails to protect 95% of soil biota. The percentage of species affected by MPs approximately doubled in SAS. Our conservative results suggest that regulatory limits on MPs in sludge being applied to land should be urgently considered.
Sign in to start a discussion.
More Papers Like This
A Quantitative Environmental Risk Assessment for Microplastics in Sewage Sludge Applied to Land
Researchers conducted a quantitative risk assessment of microplastics in sewage sludge applied to farmland and found that contamination levels frequently exceed safe thresholds for soil organisms. Even under realistic scenarios, the microplastic concentrations in sludge-amended soils were estimated to affect 15 to 18 percent of soil species. The study suggests that regulatory limits on microplastics in agricultural sludge should be urgently considered to protect soil ecosystems.
Microplastics in an agricultural soil following repeated application of three types of sewage sludge: A field study
Researchers investigated microplastics in agricultural soil after repeated sewage sludge application, finding that sludge-amended soils contained significantly more small microplastic particles than unamended soils, with particle accumulation varying by sludge type.
Soil-dwelling species-based biomarker as a sensitivity-risk measure of terrestrial ecosystems response to microplastics: A dose–response modeling approach
A dose-response modeling approach was applied to data from soil-dwelling organisms to assess the relative sensitivity of terrestrial ecosystems to microplastic contamination, producing species sensitivity distributions as a risk metric. The analysis revealed that certain soil invertebrates are particularly vulnerable even at relatively low microplastic concentrations.
Extent and impact of microplastics on soil nutrients and biota: a trade-off assessment
This review examines the extent of microplastic inputs from sewage sludge applied to agricultural soils, synthesizing evidence on how sludge-derived microplastics affect soil nutrient availability, soil biota, plant performance, and crop productivity, concluding that the benefits of sludge as a soil amendment must be weighed against its role as a vector for microplastic contamination.
Evidence of microplastic accumulation in agricultural soils from sewage sludge disposal
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.