Are Microplastics a Soil Pollutant?

• Blog
• No comments

Scandanavian research  warns growers of the high concentration of microplastic in soil.

Microplastics are tiny plastic particles used in scrubs, toothpaste and beauty products.  They also originate from the degeneration of car tyres, and surfaces composed of ( or coated with) plastics ( e.g. artificial grass) and end up as urban run-off water. All these microplastics land  in our sewage treatment plants.

Researchers are concerned about the lack of knowledge regarding potential consequences of microplastics in soil from the application of sewage sludge.

Sewage sludge is used to supplement fertilisers as it contains valuable nutrients.  Most of the microplastics accumulate in the sewage sludge,  of which about 50% ends up on fields in Europe and North America.

The scientists admit that the level of knowledge concerning the effects of microplastic on soil-dwelling animals is very low and their impact on food safety is unknown. But in 2016, high concentrations of microplastic were shown to adversely affect the fertility of earthworms; & it was thought that hormone-active substances may be absorbed by plant foods.  Are microplastics a soil pollutant?

References:

Nizzetto et al (2016): “A theoretical assessment of microplastic transport in river catchments and their retention by soils and river sediments” in Environ. Sci.: Processes Impacts, 2016, 18, 1050-1059. DOI: 10.1039/C6EM00206D

Besseling et al. (2016): “Fate of nano- and microplastic in freshwater systems: A modeling study” in Environmental Pollution, 2016. DOI: 10.1016/j.envpol.2016.10.001

Nizzetto, Futter, Langaas (2016): “Are Agricultural Soils Dumps for Microplastics of Urban Origin?“ in Environ. Sci. Technol. DOI: 10.1021/acs.est.6b04140

Nizzetto, Langaas, Futter (2016): “Pollution: Do microplastics spill on to farm soils?” in Nature 537, 488. DOI:10.1038/537488b