Microplastics ubiquitous in the environment
A new study conducted by the Umweltbundesamt (Environment Agency Austria) reveals: microplastics are now present everywhere in the environment. Experts from the Environment Agency Austria carried out an assessment of national and international studies that are currently available. A large number of analyses around the globe show that microplastics are present in water, soil and in air, but also in food, cosmetics and cleaning products. Despite an increase in data, the studies are comparable only to a limited extent. "What we need is more - and more reliable - data so that we can make better recommendations for action. To achieve this, Europe-wide standards for sampling and analysis are urgently required", says Bettina Liebmann, microplastics expert at the Environment Agency Austria.
Microplastics end up in the environment in different ways: when added to products such as cosmetics, cleaning products or paints, they are often released to the sewage system through washing. Even more relevant in terms of quantity are microplastic particles, which are formed by abrasion or fragmentation, e.g. tyre abrasion which, with 6800 tonnes generated every year (in Austria), is the biggest source of microplastics, followed by emissions from waste disposal, fibres released through clothes washing, paints that flake off from road markings and buildings, microplastics carried off by the wind from artificial grass sports pitches, and microplastics released from construction sites. The most commonly found polymer types of can be related to global plastics production.
Microplastics not only found in oceans
Analyses of drinking water indicate that there is no or hardly any microplastic contamination in tap water coming from ground and surface water sources. Bottled drinking water, however, tends to contain more microplastic particles. PET (polyethylene terephthalate) is the most common type of plastic found, due to abrasion of the packaging material. Plastic used in drinking water treatment processes or transport also contributes to contamination.
Wastewater is also affected by microplastic pollution. This is a problem, as large amounts of microplastics end up in wastewater through the washing of synthetic clothes, inappropriate disposal of personal care products or industrial effluents. Even if wastewater treatment plants remove a considerable amount of microplastics, part of them still enter the environment.
The volumes of microplastics cited in the studies vary considerably, which is inter alia due to different sampling and analytical methods.
Microplastics in soils
International data reveal that microplastic pollution is also affecting soils. The use of plastic mulches or plastic-based materials, and the application of sewage sludge, compost or fermentation residues to fields play a critical role here. In Austria, one study (from Vorarlberg) is available to date: microplastic fragments have been found by experts from the Environment Institute of Vorarlberg in several fields in the Rhine Valley.
Especially sewage sludge is a major source of microplastics entering the soil environment. Analyses carried out by experts found microplastic concentrations ranging from 1,500 to 170,000 particles per kilogramme of sewage sludge (dry weight). The most common types of plastic found were polyester, PET, PE (polyethylene) and PA (polyamide). As sewage sludge is often used as fertiliser in agriculture and landscaping, the application of sewage sludge is a major route for microplastics entering the soil.
Tyre abrasion: the biggest source of microplastics
Another entry point for microplastics to the environment is tyre abrasion. A study carried out by the Environment Agency Austria in 2015 estimated the amount of fragments created by abrasion on Austrian roads at 6,766 tonnes every year. For the whole of EU transport, an estimated 500,000 tonnes of microplastics are created by tyre abrasion every year. Compared to that, around 50,000 tonnes of microplastics are added intentionally to products every year. The quality of the tyres and the road conditions, traffic flow or the weight of the vehicles have an influence on the amount of particles that are released through abrasion.
First evidence of microplastics in air
Although there is limited data, studies have detected microplastics in air in urban environments and in remote mountain areas. Because of their small size and density, microplastics are transported over long distances and end up even in remote areas. A recently published study found microplastics in snow both in Europe and across the Arctic.
Particles that are relevant for humans and potentially dangerous to human health are those with a size smaller than ten micrometres as they can overcome barriers in the human body (e.g. skin, organs) and be inhaled by humans. Ten micrometres correspond roughly to the size of bacteria in diameter.
Microplastics in humans
A pilot study carried out by the Environment Agency Austria and the Medical University of Vienna found microplastics in human stools in 2018, in all of the eight international participants, who consumed food wrapped in plastic or drinks from PET bottles. The majority of the group ate fish and seafood. That microplastics are present in food such as fish, seafood or salt has also been revealed by other studies that were considered in the assessment. However, it is currently not clear how much microplastic is present in food and what it consists of.
