Tiny plastic particles also present a threat to creatures on land and may have damaging effects similar or even more problematic than in our oceans. Researchers from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) and their Berlin colleagues warn: the impact of microplastics in soils, sediments and the freshwaters could have a long-term negative effect on terrestrial ecosystems throughout the world.
It is now widely accepted that microplastics contaminate our oceans and are harmful to coastal and marine habitats. And yet what effect do fragments of plastic have on ecosystems “on dry land”?
This question is the subject of a research initiated by IGB in partnership with Freie Universität Berlin that reviews previous individual studies on the topic of microplastics in relation to the effect of microplastics on terrestrial ecosystems. “Although only little research has been carried out in this area, the results to date are concerning: fragments of plastic are present practically all over the world and can trigger many kinds of adverse effects. The previously observed effects of microplastics and nanoplastics on terrestrial ecosystems around the world indicate that these ecosystems may also be in serious jeopardy,” explains IGB researcher Anderson Abel de Souza Machado, who is leading the study. Researchers from IGB have demonstrated in earlier studies that microplastics might be harmful to ecosystems when ingested by aquatic key organisms.
Over 400 million tons of plastic are produced globally each year. It is estimated that one third of all plastic waste ends up in soils or freshwaters. Most of this plastic disintegrates into particles smaller than five millimetres, referred to as microplastics, and breaks down further into nanoparticles, which are less than 0.1 micrometre in size. In fact, terrestrial microplastic pollution is much higher than marine microplastic pollution – an estimate of four to 23 times more, depending on the environment. Sewage, for example, is an important factor in the distribution of microplastics. In fact, 80 to 90 per cent of the particles contained in sewage, such as from garment fibres, persist in the sludge. Sewage sludge is then often applied to fields as fertilizer, meaning that several thousand tons of microplastics end up in our soils each year.
Potentially toxic effect on many organisms
Some microplastics exhibit properties that might have direct damaging effects on ecosystems. For instance, the surfaces of tiny fragments of plastic may carry disease-causing organisms and act as a vector that transmits diseases in the environment. Microplastics can also interact with soil fauna, affecting their health and soil functions. Earthworms, for example, make their burrows differently when microplastics are present in the soil, affecting the earthworm’s fitness and the soil condition….ReadMore