Key facts
- Plastic contamination is an overlooked concern in food waste management efforts.
- Diverting food waste from landfills can reduce climate impacts by 89% to 99%.
- Microplastics can persist in compost, potentially contaminating US agricultural soils with 20,000 tonnes annually.
- Even with highly efficient separation technologies, microplastic pollution could increase significantly.
- Vermont's Universal Recycling Law mandates food waste diversion from landfills.
Plastic contamination is a significant but overlooked issue in food waste management schemes, according to researchers. A new study published in Nature Food utilized life-cycle analysis modeling to assess the impacts of various food waste management scenarios on climate, nutrient pollution, and plastic contamination.
The research, conducted by scientists at the University of Vermont, found that diverting food waste from landfills could drastically reduce climate impacts by 89% to 99% and also mitigate nutrient pollution. However, the study highlighted that composting or other recycling pathways for food waste can lead to increased microplastic contamination in agricultural soils, potentially reaching 20,000 tonnes annually in the U.S.
Lead author Kate Porterfield explained that the methodology was akin to calculating a carbon footprint, tallying emissions across all life-cycle stages of food waste management. She noted that a substantial amount of food waste still in packaging spoils before reaching consumers. Even with advanced separation technologies achieving 99% efficiency, the diversion of food waste from landfills could still result in a tenfold increase in microplastic pollution due to the prevalence of plastic packaging.
Co-author Eric Roy pointed to Vermont's Universal Recycling Law, which mandates food waste diversion from landfills, as an example of ambitious regulation. The study's findings offer an evaluation of scaling such regulations nationwide and underscore the necessity of addressing plastic contamination from the policy's inception.
Phil Holtam, director of food waste social enterprise Sussex Surplus, suggested that plastic packaging, while contributing to waste, is often a necessary trade-off for extending the shelf life of produce, particularly for smallholder farms. Max La Manna, who has experience with farmers and restaurants, added that consumer expectations for cosmetically perfect produce also contribute to food waste. Roy further noted that food safety concerns can sometimes lead to the continued use of highly packaged foods, even with well-intentioned recycling rules.