We might have unknowingly been dumping huge quantities of microplastics on our croplands. It’s all due to the high levels of these particles in sewage-sludge-derived fertilizers, reports Alexandru Micu in an article for ZME Science.
According to Micu’s report, researchers at Cardiff University estimate that anywhere between 31,000 and 42,000 tons of microplastics (or 86 – 710 trillion microplastic particles) find their way into Europe’s farmlands every year. These quantities mean that the average plot of farmland in the old world mirrors the microplastic levels of ocean surface waters, they add.
As for the source of these plastics, the team points to sewage sludge, a material that is commonly used as feedstock for fertilizers on farmlands across Europe. They estimate that around 1% of the weight of sewage sludge is made up of microplastics.
The UK has potentially the highest amounts of microplastic contamination in its soil, with between 500 and 1000 particles per square meter of agricultural land applied per year, judging from mean fertilizer (from sewage sludge) use annually. Spain, Portugal, and Germany follow.