0
Meta Analysis Tier 1 Environmental Sources Marine & Wildlife Sign in to save

Microplastics have shape- and polymer-dependent effects on soil processes

2020 26 citations

AI summary Read the abstract

This meta-analysis combined published research with lab experiments to show that microplastic shape matters when it comes to soil health effects. Fibers were especially harmful to soil structure regardless of their chemical makeup, while films and foams have been largely overlooked in research. Since healthy soil is essential for growing safe food, understanding how different microplastic shapes affect soil helps us grasp the full scope of plastic pollution's impact.

Study Type Review

Abstract Microplastics are a diverse and ubiquitous contaminant, a global change driver with potential to alter ecosystem properties and processes. Microplastic-induced effects in soils are manifold as microplastics differ in a variety of properties among which the shape is of special interest. Microplastic shapes can resemble natural forms or be dissimilar from natural objects. Our knowledge is limited regarding the impact of various microplastic shapes on soil processes. Therefore, we conducted this two-part research comprising a meta-analysis on published literature and a lab experiment focusing on microplastic shapes- and polymer-induced effects on soil aggregation and organic matter decomposition. We here focus on fibers, films, foams and fragments as microplastic shapes. In the meta-analysis, we revealed a strong research focus on fibrous and particulate microplastic materials, with films and foams neglected. Our experiment showed that microplastic shapes are important modulators of responses in soil aggregation and organic matter decomposition. Fibers, irrespective of their chemistry, negatively affected the formation of aggregates. This supported the shape dissimilarity hypothesis. However, for other shapes like foams and fragments, the polymer identity is clearly an important factor co-modulating the soil responses. Further research is needed to generate a data-driven foundation to build on our developing mechanistic understanding of the importance and consequences of microplastic shapes added to our soils.

More Papers Like This

Meta Analysis Tier 1

Microplastics have shape- and polymer-dependent effects on soil aggregation and organic matter loss – an experimental and meta-analytical approach

AI summary Read the abstract

This meta-analysis combined with lab experiments shows that different shapes of microplastics affect soil differently. Fiber-shaped microplastics were especially harmful, breaking apart soil structure and increasing the loss of organic matter — changes that could reduce soil health and crop productivity over time.

Article Tier 2

Microplastics Increase Soil pH and Decrease Microbial Activities as a Function of Microplastic Shape, Polymer Type, and Exposure Time

AI summary Read the abstract

Researchers tested twelve different types of microplastics in soil and found that their effects on soil health depended heavily on the shape, plastic type, and how long they were present. Foam and fragment shapes raised soil pH the most, while polyethylene foam increased soil respiration, and several types reduced the activity of important soil enzymes. These findings help explain why microplastic studies often show conflicting results, since the specific characteristics of the plastic matter as much as its presence.

Meta Analysis Tier 1

Effects of Environmentally Relevant Microplastic and Nanoplastic Concentrations on Soil Hydro-Physical Properties: A Global Meta-Analysis

AI summary Read the abstract

This global meta-analysis found that microplastics and nanoplastics in soil reduce its ability to hold water and maintain healthy structure. These changes to soil properties could affect crop growth and water cycling in agricultural areas, with fiber-shaped plastics causing the most disruption.

Article Tier 2

Microplastic shape, concentration and polymer type affect soil properties and plant biomass

AI summary Read the abstract

Experiments showed that microplastic shape, concentration, and polymer type all influence soil physical properties and plant biomass, with certain types reducing plant growth. The findings highlight that the wide variety of plastic particle types entering soils creates complex and variable ecological risks.

Article Tier 2

Microplastics affect soil bacterial community assembly more by their shapes rather than the concentrations

AI summary Read the abstract

Researchers conducted a two-year field study examining how different shapes of polyethylene microplastics affect soil bacterial communities and found that shape matters more than concentration. Fiber and fragment-shaped microplastics caused the most significant changes in bacterial diversity and community structure compared to spherical or powder forms. The findings challenge the common assumption that microplastic concentration is the primary factor driving ecological impacts in soil.

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.

Email me about

Share this paper