Research & reports

Javier Bayo, Joaquín López-Castellanos, Marta Doval-Miñarro, Sonia Olmos · Scientific Reports · Spain

An ATR-FTIR analysis of 11 commercial compost products found microplastics in every sample, averaging 137.65 ± 6.01 items/kg dry weight and up to 631.14 mg/kg. Eco-labeled composts had significantly lower microplastic abundance, size, and concentration than non-eco products. Microplastic concentration correlated negatively with pH and nitrogen content and positively with organic matter content.

Géant Basimine Chuma, Jean M. Mondo, Adrien Byamungu Ndeko, Etienne M. Akuzibwe, Espoir Mukengere Bagula, Gustave Nachigera Mushagalusa · Discover Sustainability · Democratic Republic of Congo (Bukavu City)

This study investigated the quantity, composition, and disposal practices of domestic waste in Bukavu City, Eastern D.R. Congo. Findings revealed significant challenges in waste management infrastructure and practices, showing that approximately 5% of waste undergoes composting, while 10% is used as livestock feed, 66% incinerated, and 17% buried. Waste management is primarily handled by children (82%), with very limited involvement from non-governmental organizations.

Jaume Vilasís Pamos, Pablo Aránguiz, Stefhania Lozano, Guillermo Palau Salvador · Revista Lecciones Vitales · Spain (Valencia)

This study examines urban agriculture initiatives in Valencia, Spain, which adopt an agroecological approach to promote sustainable practices like composting. While these collective strategies aim for sustainable agricultural models and contribute to food sovereignty, they face significant challenges, particularly regarding access to water. The initiatives also engage in political action and promote equitable organizational models.

Anne-Kristin Løes, Sebastian Eiter, Tatiana Rittl · Environmental Sciences Europe · Europe

Using soil data from ten peri-urban case farms near Oslo and Bergen, Norway, this study estimated how quickly potentially toxic element (PTE) concentrations would rise in soil under intensive application of compost or digestate from food waste, composted garden waste, or horse and poultry manure applied annually to meet a theoretical carrot crop's nitrogen, phosphorus and potassium demand. Under this intensive fertilization scenario, Norwegian soil quality limits for PTEs would be reached within 20-85 years, faster in soils with more organic matter, with limits reached first for copper and zinc, both essential micronutrients. The urban waste-based fertilizers were also found to be poorly balanced in macronutrients, with rates covering potassium demand leading to high phosphorus and nitrogen surpluses. The study concludes Norway's PTE regulations are stricter than the EU's and do not support recycling organic matter and nutrients from urban waste.

Danielle Purkiss, Ayşe Lisa Allison, Fabiana Lorencatto, Susan Michie, Mark Miodownik · Frontiers in Sustainability · United Kingdom

A citizen-science study invited 9,701 UK residents to test how biodegradable and compostable plastics actually degrade in home composting. Many items, including certified products, failed to fully break down; 60% of TUV OK Compost Home-certified items were still clearly visible afterward. The authors conclude home composting is not an effective or environmentally beneficial disposal method for these materials in the UK.

Marta Bożym · Ochrona Środowiska i Zasobów Naturalnych · Poland

A study measuring heavy-metal content (cadmium, lead, copper, zinc, nickel, chromium) in compost and resident earthworms sampled from home composters and allotment gardens in the Opole region of Poland. The compost samples themselves were not contaminated with heavy metals and stayed within Polish legal limits for solid organic fertilizers. However, metal accumulation in earthworms varied by metal: the bioaccumulation factor (BAF) was high for cadmium, lead and zinc, while no accumulation was found for nickel, chromium or copper. The authors conclude that earthworm species native to Poland, such as Eisenia fetida, can serve as potential bioindicators of metals in the environment.