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Meta Analysis ? AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button. Tier 1 ? Systematic review or meta-analysis. Synthesizes findings across many studies. Strongest evidence. Environmental Sources Human Health Effects Sign in to save

Microplastics andSoil Greenhouse Gas Emissions: ACritical Reflection on Meta-Analyses

Figshare 2025
Linjie Zhang (1476433), Chenya Wang (3944234), Bing Xie (234712)

Summary

This meta-analysis found that different types of microplastics in agricultural soil affect greenhouse gas emissions in varying ways, with some plastics increasing methane and carbon dioxide output. While focused on environmental impact rather than direct health effects, the findings highlight how microplastic contamination of farmland can have far-reaching consequences for both climate and food production.

Study Type Review

Microplastics (MPs) are widespread in agricultural soils and may influence emissions of greenhouse gases (GHGs), though their specific impacts remain uncertain. This study utilized conventional and network meta-analysis to evaluate the effects of long-term exposure to environmentally relevant MP concentrations. Results showed that, compared with uncontaminated soil, polypropylene increased CH4 emissions by 2.01 times, while polyethylene terephthalate reduced them to 0.47 times. Polybutylene adipate terephthalate (PBAT) and polylactic acid/PBAT increased CO2 emissions by 3.13 and 2.70 times, respectively; polyethylene raised N2O emissions by 1.52 times. Other MPs had no significant impact. Most types of MPs increased GHG emissions, with conventional MPs contributing more to N2O emissions and biodegradable MPs contributing more to CO2 emissions. Biodegradable plastics were not necessarily more environmentally friendly in terms of global warming potential. Moreover, the study summarized issues in current meta-analyses targeting MPs, emphasizing the need to prioritize MP types, account for correlations and interactions among moderators, ensure effect size independence, and address potential “P-hacking” during the discretization of continuous variables. This deepens our comprehension of the environmental impacts of MPs and provides valuable guidance for future meta-analyses to accurately assess effects of MPs.

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