Plastic pollution: useful measures here, new concerns there

The problem of plastic pollution is widely known by now. Since the first production of synthetic polymers the amount of produced plastic worldwide has risen exponentially. Up to the year 2015, approximately 8.3 billion tons of plastic have been produced. And while plastic products do bring with them certain benefits, the handling of plastic waste raises serious questions. About 6.3 billion tons of the produced plastic to date has reached the end of its lifecycle. However, only 9% of this is recylced, while the majority of plastic waste (app. 79%) ends up in landfills or the environment. Pictures of trash lying on agricultural fields or floating in rivers, lakes and the oceans cause strong reactions from the public. The quantification of plastic production and its paths through the anthroposphere however bear large benefits: plastic pollution is widely accepted as a problem of our society and correspondingly, actions are being taken.

Germany takes action against plastic waste

Several measures to reduce the amount of plastic waste are already in place, as a matter of fact. The European Union passed a ban on single-use plastics at the beginning of this year and in Switzerland, a tiny charge on single use plastic bags are showing a strong effect. The German cabinet is now taking things one step further. “Plastic bags are the epitome of wasteful use of our resources: they are produced from crude oil and are mostly used for only a couple of minutes. Then they likely end up somewhere in the environment where they persist for several decades and may cause damages”, says Svenja Schulze, head of the federal environmental ministry of Germany. Her proposal to ban plastic bags with a wall thickness below 50 micrometers was accepted by the German cabinet at the beginning of November. The bill is intended to also reach those final distributors which previously did not partake in the current voluntary agreement. Schulze aims to reduce the use of single use plastic bags per person from 20 per year to zero with this measure.
The proposal is restricted to those bags with wall thickness below 50 micrometers because they are easier to remove from the market since they are reused far less then bags made of stronger materials. It further includes an exception concerning the small bags often used for vegetables and fruits. These only have a wall thickness of 15 micrometers and a ban would likely result in the use of more resource-intensive alternatives.

Reduce, Reuse, Recycle – there are alternatives available

Possible alternatives for consumers are reusable bags made from synthetic materials or polyester. After only a couple uses they are already more environmentally friendly than the single- use plastic bags and the more consumers use them, the more eco-friendly they get. “The future is not the single-use plastic bag. The future is reusable – and for bags, this is really not hard to achieve. A reusable bag out of plastic is more eco-friendly than a single-use one after just three uses. They are also mostly produced from recycled materials instead of crude oil”, Schulze says.

Large amounts of rubber wear in the environment

Once plastic reaches the environment it takes a long time to degrade. It breaks into small particles, microplastics which is under suspicion to cause strong detrimental effects on living organisms. Now, attention is shifting to a new type of tiny particles: tire abrasion also produced such small particles, called micro-rubber. According to the Fraunhofer Institute for the environment, security and energy technology (UMSICHT) only about 7% of synthetic particles found in the environment are made of plastic, while micro-rubber accounts for the lion’s share of 93%. Now scientists from the Swiss Federal Laboratories for Materials Science and Technology in St. Gallen have calculated the input of micro-rubber into the environment. The material flow analysis was conducted for Switzerland between the years 1988 and 2018. It included data on the life cycle of tires from import to their decommissioning as well as possible reuse. Only about a quarter of total micro-rubber mass is retained by treatment plants located in close proximity to the streets. The calculations resulted in an estimated 7'500 tons per year reaching in the environment. The majority of this (74%) ends up in roadside soils within approximately 5 meters. The rest is distributed in surface waters (22%) and other soils. Between 1990 and 2018 the amount of micro-rubber entering the environment has furthermore increased by approximately 10%.

Data is still scarce on micro-rubber

While the discussion on risks caused by microplastics is in full effect, there is only very little data on micro-rubber and its possible effects. “For humans this should not really constitute a problem as we can not inhale any micro-rubber since none of it is airborne. It may be different for organisms living in soils where most micro-rubber ends up. It may cause problems there, but at this point in time, not enough scientific investigations have been conducted in this regard”, Bernd Nowack, main author of the study, explains in an interview with the Swiss TV station, SRF. Further studies on this subject have however been commissioned already.

Author: Alex von Wyl

Sources:

Original article (Pre-proof) and image source: "Dynamic probabilistic material flow analysis of rubber release from tires into the environment"

«Weniger ist mehr»-campaign of the German ministry of environment (German): https://www.bmu.de/wenigeristmehr/

Swiss Television News on Micro-rubber (German): https://www.srf.ch/play/tv/tagesschau/video/mikrogummi-in-der-umwelt?id=57a98f7f-b723-4499-ab47-dcd5adb71702