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Bio-based Plastics Biodegradability Myth Busted: Wageningen Study Reveals Lasting Negative Impact


Wageningen University in the Netherlands has recently conducted a pivotal study that challenges the widely held belief in the biodegradability of bio-based plastics. This research, commissioned by the Dutch environmental charity Plastic Soup Foundation, reveals alarming findings about the longevity of so-called “biodegradable” bioplastics in agricultural soils.

The Study’s Alarming Findings


The study examined soil samples from ditches surrounding agricultural fields at eight flower farms in the Netherlands and eight coriander farms in Spain. Astonishingly, researchers found approximately 3,000 microplastics per gram of sediment, indicating significant environmental microplastic accumulation. This finding was further compounded by the discovery of 48 different types of microplastics in the tested samples, with 61% derived from fossil fuels and the remaining 39% from biological origins​​.

Debunking Biodegradability Claims


A major revelation of the study was the persistence of “biodegradable” plastic mulches in soil beyond the industry-prescribed two-year degradation period, thereby violating the EN 17033 standard. Dr. Esperanza Huerta Lwanga, the study’s lead researcher, emphasized the seriousness of this finding, noting that biodegradable plant-based mulches developed to quickly degrade in soil do not live up to these claims. Instead, these particles move from soils and accumulate in sediments where they fail to degrade any further​​

The Impact on Agricultural Practices


The study's results have significant implications for agricultural practices. Maria Westerbos, director of the Plastic Soup Foundation, highlighted that farmers increasingly use biodegradable plastic mulches under the false promise of degradability within two years. These mulches, which are supposed to degrade and be plowed under, instead pose a risk of contaminating the soils where our food is grown​​.

Call for Action and Regulatory Reforms


In light of these findings, environmental campaigners and organizations are calling for stricter regulations on environmental claims made by bioplastic manufacturers. The study has sparked advocacy for comprehensive measures to combat plastic pollution globally. The upcoming review of the EU Fertiliser regulation in July 2024 is a crucial juncture where the findings of this research must be considered. The Plastic Soup Foundation and other environmental organizations are advocating for a strong and comprehensive treaty to address plastic pollution at the Global Plastic Treaty negotiations at the United Nations Environmental headquarters​​​​.

Rethinking Solutions


To address the concerns raised by the study, companies like Mondi have joined forces with Cotesi to develop more sustainable solutions, such as Advantage Kraft Mulch, a 100% compostable kraft paper solution without plastic or coating. This development suggests a growing awareness and effort to find truly sustainable alternatives to plastic mulch in agriculture​​.

The Wageningen University study serves as a stark reminder of the complexities and challenges in achieving true sustainability in agricultural practices. It calls for a critical reassessment of the materials we use and a push for genuine solutions that align with environmental and ethical standards. As we move forward, it is imperative that both the industry and regulatory bodies take these findings seriously and work towards developing and enforcing standards that ensure the protection of our environment and the health of our ecosystems.


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