In an article published on April 5, 2018 by the magazine Science News, writer Rachel Ehrenberg reported on a new study on organic fertilizers as a source of microplastic pollution. The study was published on April 4, 2018 in the peer-reviewed journal Science Advances and conducted by Nicolas Weithmann and colleagues from the University of Bayreuth, Germany.
The researchers analyzed different types of organic fertilizers from plants converting biowaste into energy for occurrence of plastic particles. They found that compost from supermarket waste contained the highest amount of plastic particles (895 pieces >1 mm per kg dry weight). Also in household compost microplastics were abundant (20-24 pieces per kg of dry weight). Styrene-based polymers, polyethylene, and polyester were the most frequent types of plastic found in household compost. All these are commonly used in food packaging. In contrast, digestates from agricultural biogas production contained only isolated or even no plastic particles at all.
Organic fertilizers from biowaste fermentation and composting are used in agriculture and gardening around the world. Consequently, “plastic gets spread over fields, where it may be eaten by worms and enter the food web, make its way into waterways or perhaps break down further and become airborne,” according to Christian Laforsch, the study’s corresponding author.
Rachel Ehrenberg (April 5, 2018). “Microplastics may enter freshwater and soil via compost.” Science News
Weithmann, N., et al. (2018). “Organic fertilizer as a vehicle for the entry of microplastic into the environment.” Science Advances (published online April 4, 2018).